From MCD at goshenarc.org Thu Dec 1 06:32:22 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 01 Dec 2005 01:32:22 -0500 Subject: [MCD] SWOMCD Message-ID: <200512010630.jB16UgO4017705@mail.goshen.edu> ACUS11 KWNS 010630 SWOMCD SPC MCD 010629 IDZ000-NVZ000-ORZ000-011130- MESOSCALE DISCUSSION 2514 NWS STORM PREDICTION CENTER NORMAN OK 1229 AM CST THU DEC 01 2005 AREAS AFFECTED...SWRN ID / SERN OREGON / FAR NRN NV CONCERNING...HEAVY SNOW VALID 010629Z - 011130Z SNOW IS LIKELY TO INCREASE IN COVERAGE AND INTENSITY THROUGH THE NIGHT FROM SERN OREGON ACROSS NRN NV AND INTO SWRN ID. SNOW RATES NEAR 1 IN/HR WILL BE POSSIBLE. THERMAL GRADIENT WILL TIGHTEN A BIT ACROSS OREGON...NRN NEVADA...SRN IDAHO AND NRN UT AS WARM ADVECTION PERSISTS. RESULTING FRONTOGENETIC FORCING AND INCREASE IN PRECIPITABLE WATER VALUES IS EXPECTED TO INCREASE PRECIPITATION RATES ACROSS THE AREA. RUC AND NAM SOLUTIONS ARE IN GOOD AGREEMENT SUGGESTING HEAVIEST SNOW RATES MAY OCCUR OVER SWRN ID AND FAR NRN NV. FURTHER...THERMODYNAMIC PROFILES WILL FAVOR DENDRITIC AND AGGREGATE GROWTH. ..JEWELL.. 12/01/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...PIH...BOI...LKN... 41381454 41111603 41451793 41901888 42801848 42961763 43251681 42441469 42021415 WWWW From MCD at goshenarc.org Sat Dec 3 11:43:53 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sat, 03 Dec 2005 06:43:53 -0500 Subject: [MCD] SWOMCD Message-ID: <200512031142.jB3Bg5Lv001471@mail.goshen.edu> ACUS11 KWNS 031141 SWOMCD SPC MCD 031141 NYZ000-031545- MESOSCALE DISCUSSION 2515 NWS STORM PREDICTION CENTER NORMAN OK 0541 AM CST SAT DEC 03 2005 AREAS AFFECTED...W CNTRL NY CONCERNING...HEAVY SNOW VALID 031141Z - 031545Z LAKE EFFECT SNOW BAND/BANDS EMANATING FROM LAKE ONTARIO SHOULD PERSIST INTO THE AFTERNOON ACROSS W CNTRL NY FROM NEAR FULTON TO NEAR SYRACUSE AND ORISKANY. SNOWFALL RATES LOCALLY FROM 1 TO 1.5 INCHES PER HOUR MAY CONTINUE NEXT FEW HOURS. HOWEVER...INTENSITIES MAY GRADUALLY DECREASE THROUGH THE MORNING. LAKE EFFECT SNOW BANDS FROM FULTON TO ORISKANY ARE EXPECTED TO CONTINUE INTO THE AFTERNOON. THE BAND WAS MORE INTENSE EARLIER THIS MORNING WITH A SINGLE BANDED STRUCTURE BUT APPEARS TO HAVE WEAKENED SLIGHTLY AND BECOME LESS ORGANIZED DURING THE LAST HOUR. THIS BAND APPEARS TO HAVE MULTIPLE CONNECTIONS WITH TRAJECTORIES FROM LAKE SUPERIOR AND LAKE HURON AS WELL AS A FAIRLY LONG FETCH ACROSS LAKE ONTARIO. WNWLY BOUNDARY LAYER FLOW...VERY COLD TEMPERATURES WITH -13C AT 850 MB AND STEEP LOW LEVEL LAPSE RATES WILL PERSIST THIS MORNING OVER LAKE ONTARIO. HOWEVER...MID LEVEL HEIGHTS WILL CONTINUE TO RISE AND UPPER RIDGE WILL BUILD IN WAKE OF UPPER LOW LIFTING NWD THROUGH QUEBEC. BUILDING HEIGHTS WILL BE ACCOMPANIED BY WARMING IN THE 700 TO 750 MB LAYER AND A LOWERING OF INVERSION HEIGHTS WHICH SHOULD CONTRIBUTE TO LESS INTENSE BANDS WITH TIME. ..DIAL.. 12/03/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...ALY...BGM...BUF... 43557557 43067455 42567468 42877603 43207725 43617722 WWWW From MCD at goshenarc.org Sat Dec 3 18:27:49 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sat, 03 Dec 2005 13:27:49 -0500 Subject: [MCD] SWOMCD Message-ID: <200512031826.jB3IQ2t1019932@mail.goshen.edu> ACUS11 KWNS 031825 SWOMCD SPC MCD 031825 INZ000-ILZ000-WIZ000-IAZ000-MOZ000-NEZ000-KSZ000-040030- MESOSCALE DISCUSSION 2516 NWS STORM PREDICTION CENTER NORMAN OK 1225 PM CST SAT DEC 03 2005 AREAS AFFECTED...EXTREME NRN KS/SERN NEB/IA/SRN WI/NRN IL CONCERNING...HEAVY SNOW VALID 031825Z - 040030Z ...MODERATE TO HEAVY SNOW IS EXPECTED THIS AFTN ACROSS MAINLY SERN NEB/IA WITH SNOW INCREASING ACROSS SRN WI/NRN IL. HOURLY RATES WILL RANGE FROM 1 TO 2 INCHES... SEVERAL FACTORS WILL CONTRIBUTE TO BANDS OF MODERATE TO HEAVY SNOW THIS AFTN. ON THE SYNOPTIC SCALE...A SHORTWAVE TROUGH IS NOW LIFTING NEWD FROM KS/NEB...AND THIS PLACES THE ENTIRE AREA WITHIN A ZONE OF LARGE SCALE SLOPED ASCENT. SOME JET COUPLING IS ALSO LIKELY OCCURRING AS 12Z UPPER AIR ANALYSIS DEPICTS JET STREAK ACROSS SRN KS/MO AND ANOTHER DEPARTING JET MAX FROM IND INTO THE MID ATLANTIC. A BAND OF MODERATE TO HEAVY SNOW HAS BEEN ONGOING FOR THE LAST SEVERAL HOURS ACROSS SERN NEB INTO IA PER LOCAL RADAR IMAGERY...WITH MODERATE/HEAVY SNOW NOW EXTENDING FROM NEAR HARLAM IA TO JUST NORTH OF DSM...FROM AMES TO MARSHALLTOWN. FAVORABLE MID LEVEL FRONTOGENETICAL FORCING WILL ENCOURAGE NARROW BUT HEAVY MESOSCALE BANDS OF SNOW. THERMODYNAMIC PROFILES LOOK VERY SUPPORTIVE OF HEAVY SNOW...WITH FORECAST SOUNDINGS SUGGESTING DEEP LIFT THROUGHOUT THE DENDRITIC LAYER EXTENDING FROM 700-500MB. LATEST NAM GUIDANCE SUGGESTS HEAVIEST SNOWS WILL SET UP FROM ERN IA ALONG THE WI/IL BORDER BETWEEN 21Z-00Z. EXPERIMENTAL SHORT RANGE ENSEMBLE SOLN SUPPORTS THIS WITH MEAN 1 INCH PER HOUR RATES CONTINUING ACROSS MUCH OF CNTRL/ERN IA THIS AFTN BEFORE SPREADING TO NEAR MKE/ORD BY 04/00Z. ..TAYLOR.. 12/03/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LOT...MKX...DVN...ARX...DMX...EAX...OAX...TOP...GID... 41638865 39489733 40099833 41979563 43229242 43478986 43338758 41688715 WWWW From MCD at goshenarc.org Sat Dec 3 21:55:00 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sat, 03 Dec 2005 16:55:00 -0500 Subject: [MCD] SWOMCD Message-ID: <200512032153.jB3LrCVv006513@mail.goshen.edu> ACUS11 KWNS 032151 SWOMCD SPC MCD 032151 TNZ000-ALZ000-MSZ000-MOZ000-ARZ000-032345- MESOSCALE DISCUSSION 2517 NWS STORM PREDICTION CENTER NORMAN OK 0351 PM CST SAT DEC 03 2005 AREAS AFFECTED...ERN AR...WRN TN...NRN MS...NWRN AL CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 032151Z - 032345Z A WATCH MAY BE REQUIRED ACROSS PORTIONS OF THE LOWER/MIDDLE MS RIVER VALLEY AREA WITHIN 2 HOURS. WV SATELLITE IMAGERY WAS DEPICTING STRONG MID/UPPER LEVEL IMPULSE MOVING RAPIDLY EAST ACROSS THE SRN PLAINS LATE THIS AFTERNOON. SURFACE LOW PRESSURE WAS DEEPENING IN RESPONSE TO THIS IMPULSE AND WAS RECENTLY LOCATED OVER THE OZARKS OF SRN MO/NRN AR. IN ADDITION... A SHARP COLD FRONT WAS SPREADING STEADILY ESEWD FROM ERN OK AND WRN AR AS A WARM FRONT WAS RETREATING GRADUALLY NWD AHEAD OF THE SURFACE LOW...FROM NERN AR TO WRN TN TO NWRN AL. RECENT RUC AND ACARS SOUNDINGS ARE BEGINNING TO SUGGEST A GRADUAL EROSION OF THE CAPPING INVERSION IN THE 800-700MB LAYER ACROSS AR AS LARGE SCALE ASCENT/DPVA SPREADS EAST WITH THE MID/UPPER LEVEL SHORT WAVE TROUGH. HOWEVER...RECENT ACARS SOUNDINGS FROM MEM AREA ARE STILL INDICATING A RELATIVELY STRONG CAPPING INVERSION AT THE BASE OF THE ELEVATED MIXED LAYER AROUND 800MB. MEANWHILE...WARM SECTOR BOUNDARY LAYER FROM LA TO WRN TN CONTINUES TO WARM/MOISTEN WITH LATEST OBJECTIVE ANALYSIS DATA INDICATING 500-1000 MLCAPE IN THIS CORRIDOR. EXPECT THAT DEEP LAYER CONVERGENCE AND ADIABATIC COOLING ACCOMPANYING THE MID/UPPER IMPULSE AND ASSOCIATED COLD FRONT/SURFACE LOW WILL PROVE ADEQUATE TO LOCALLY OVERCOME INHIBITION ACROSS ERN AR WITHIN THE NEXT 1-2 HOURS. RESULTING STORMS WILL DEVELOP IN A STRONGLY SHEARED ENVIRONMENT WHERE SWLY/WSWLY FLOW ACROSS THE WARM SECTOR INCREASES TO OVER 50KT AT 850MB. THIS ENVIRONMENT WILL SUPPORT SUPERCELLS WITH HAIL AND WIND DAMAGE POTENTIAL POSSIBLY EVOLVING INTO A SQUALL LINE AS THE FRONT MOVES EAST ACROSS THE MS RIVER LATER THIS EVENING. ..CARBIN.. 12/03/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...OHX...HUN...MEG...JAN...LZK... 35119086 36208999 36398799 35268724 33848953 33209130 33349165 WWWW From MCD at goshenarc.org Sun Dec 4 01:00:04 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sat, 03 Dec 2005 20:00:04 -0500 Subject: [MCD] SWOMCD Message-ID: <200512040058.jB40wHKY025891@mail.goshen.edu> ACUS11 KWNS 040057 SWOMCD SPC MCD 040056 MDZ000-VAZ000-PAZ000-WVZ000-OHZ000-KYZ000-INZ000-040700- MESOSCALE DISCUSSION 2518 NWS STORM PREDICTION CENTER NORMAN OK 0656 PM CST SAT DEC 03 2005 AREAS AFFECTED...SRN IND/SRN OH/NRN KY/WV/WRN MD/NRN VA CONCERNING...FREEZING RAIN AND SLEET VALID 040056Z - 040700Z ...AREAS OF FZRA AND SLEET LIKELY THIS EVENING AND OVERNIGHT OVER PORTIONS OF THE OH VALLEY INTO THE CNTRL APPALACHIANS... ELEVATED CONVECTION/OVERRUNNING PCPN IS ALREADY MOVING NORTH OF THE OH RIVER...WHERE SFC TEMPS ARE AT OR BELOW FREEZING. WARMER TEMPERATURES WITHIN THE 750-800MB LAYER PER 00Z SOUNDINGS ARE RESULTING IN FREEZING RAIN ACROSS SRN IND/SRN OH. LARGE SCALE ASCENT WILL INCREASE AHEAD OF MID LEVEL SHORTWAVE NOW OVER THE UPPER MIDWEST. LATEST VAD WIND DATA FROM LOUISVILLE AND JACKSON KY INDICATE AT LEAST A 40-45 KT LLJ AROUND THE 1-2 KM AGL LAYER WITH 50 KT OBSERVED AT 850MB ON THE 00Z MEMPHIS SOUNDING. THE LLJ /850MB FLOW/ IS FORECAST TO INCREASE TO NEARLY 70KT BY 06Z WHICH WILL MAINTAIN STRONG WAA/ISENTROPIC LIFT ACROSS SRN OH/WV THIS EVENING. AMBIENT AIRMASS AT THE SFC IS VERY DRY...WITH DEWPOINTS IN THE TEENS IN MANY LOCATIONS. ALL THE SHORT TERM MODELS ARE TOO SLOW WITH BREAKING OUT PRECIPITATION GIVEN CURRENT TRENDS. HOWEVER RUC/NAM PTYPE ALGORITHMS DO AGREE THAT FZRA POSSIBLY MIXING WITH SLEET WILL DEVELOP ACROSS MUCH OF WV/NWRN VA/SRN OH AND POSSIBLY INTO SW PA THROUGH 04-06Z. FORECAST SOUNDINGS SUGGEST SOME OF THE HEAVIEST FZRA WILL LIKELY FALL AFTER 06Z ACROSS WV/NRN VA...WITH A STRONG INVERSION /+2 TO +4C/ NOTED IN THE 850-700MB LAYER ATOP A SUBFREEZING SFC AIRMASS. ..TAYLOR.. 12/04/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...CTP...LWX...RNK...PBZ...RLX...CLE...JKL...ILN...LMK...IWX...IND...PAH... 37467937 38178286 38498735 39488753 40328719 40157975 39767751 38517797 WWWW From MCD at goshenarc.org Sun Dec 4 01:18:07 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sat, 03 Dec 2005 20:18:07 -0500 Subject: [MCD] SWOMCD Message-ID: <200512040116.jB41GJpv032139@mail.goshen.edu> ACUS11 KWNS 040115 SWOMCD SPC MCD 040115 TNZ000-KYZ000-ILZ000-MOZ000-040315- MESOSCALE DISCUSSION 2519 NWS STORM PREDICTION CENTER NORMAN OK 0715 PM CST SAT DEC 03 2005 AREAS AFFECTED...EXTREME SERN MO...WRN/S CNTRL KY...NWRN/NRN MIDDLE TN CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 040115Z - 040315Z ELEVATED CONVECTION IS BEGINNING TO DEVELOP FROM SERN MO INTO EXTREME WRN KY AND NWRN TN. PARTS OF KY AND TN WILL BE MONITORED FOR INCREASING THUNDERSTORM DEVELOPMENT AND POSSIBLE WW. STRONG MID/UPPER LEVEL JET STREAK IS MOVING EWD ACROSS OK INTO AR...WITH INCREASING DYNAMIC FORCING FOR LARGE SCALE ASCENT APPROACHING THE LOWER OH VALLEY REGION. SWLY LOW LEVEL JET OF 45-55 KT EXTENDS FROM MS INTO MIDDLE TN...AND IS PROVIDING STRONG WARM ADVECTION LIFT ALONG AND NORTH OF THE WARM FRONT THAT CURVES FROM A LOW ALONG THE AR/TN BORDER SEWD INTO CENTRAL AL. RUC SOUNDINGS INDICATE PRESENCE OF ELEVATED INSTABILITY ABOVE THE COOL SURFACE LAYER NORTH/NORTHEAST OF THE SURFACE FRONT...AND ALTHOUGH MODEL LAPSE RATES ALOFT ARE MODEST...VERY STRONG DEEP LAYER SHEAR WILL ENHANCE UPDRAFT STRENGTH SUGGESTING POTENTIAL FOR HAIL FORMATION IN STRONGER CELLS. WE ARE MONITORING THIS AREA FOR POSSIBLE WW. ..WEISS.. 12/04/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MRX...JKL...LMK...OHX...PAH...MEG... 36818968 37298855 37568616 37508415 36848355 35958417 35748713 35668890 35848956 WWWW From MCD at goshenarc.org Sun Dec 4 01:46:41 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sat, 03 Dec 2005 20:46:41 -0500 Subject: [MCD] SWOMCD Message-ID: <200512040144.jB41isd0011981@mail.goshen.edu> ACUS11 KWNS 040143 SWOMCD SPC MCD 040143 PAZ000-NYZ000-WVZ000-OHZ000-MIZ000-INZ000-ILZ000-WIZ000-IAZ000-040645- MESOSCALE DISCUSSION 2520 NWS STORM PREDICTION CENTER NORMAN OK 0743 PM CST SAT DEC 03 2005 AREAS AFFECTED...CNTRL AND NRN IL/SERN WI/SRN LOWER MI/NRN IND/NRN OH/WRN PA CONCERNING...HEAVY SNOW VALID 040143Z - 040645Z PERIODS OF MODERATE TO OCNL HEAVY SNOW WILL CONTINUE ACROSS NRN AND CNTRL IL/SERN WI SPREADING INTO NRN IND/LOWER MI WITHIN THE NEXT FEW HOURS. HRLY SNOW RATES WILL BE AROUND 1 INCH. ACROSS CNTRL IL...A MIX OF FZRA AND SLEET IS EXPECTED FOR ANOTHER 1-2 HOURS. PCPN IS FILLING IN RAPIDLY ACROSS CNTRL/NRN IL IN RESPONSE TO INCREASING LARGE SCALE LIFT FROM UPSTREAM WAVE. MEANWHILE...ORIGINAL DEFORMATION BAND FROM EARLIER IN THE AFTN HAS MOVED INTO LOWER MI. 00Z SOUNDINGS FROM KILX /CENTRAL IL/ AND KILN /WILMINGTON OH/ BOTH SHOW A SUBTLE INVERSION...NEAR THE 750-800MB LAYER. TEMPERATURES ON THE CNTRL IL SOUNDING ARE MAINLY BELOW FREEZING WITH THE EXCEPTION OF A VERY SHALLOW WARM LAYER NEAR 800MB. THIS HAS BEEN SUFFICIENT TO ALLOW FOR FREEZING RAIN AT SEVERAL LOCATIONS. HOWEVER...FORECAST SOUNDINGS SUGGEST PCPN SHOULD CHANGE OVER TO SNOW WITHIN AN HOUR OR TWO. DOWNSTREAM...FZRA MAY PERSIST FOR A FEW HOURS THIS EVENING MAINLY SOUTH OF A MUNCIE/INDIANAPOLIS LINE /REFER TO MCD 2518 FOR MORE INFO/. ACROSS LOWER MI/NRN IND...PROFILES ARE COLD ENOUGH THROUGH A DEEP LAYER TO SUPPORT ALL SNOW. STRONG LIFT THROUGH A SATURATED DENDRITIC LAYER WILL CONTRIBUTE TO HEAVIER SNOW RATES...UP TO AN INCH PER HOUR. SNOW WILL EVENTUALLY SPREAD INTO WRN/CNTRL PA AROUND 06Z. ..TAYLOR.. 12/04/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...BUF...CTP...PBZ...CLE...ILN...DTX...IWX...GRR...IND...LOT...ILX...MKX...DVN... 40428707 39768875 39879009 40139047 40539079 41079075 42968936 43508837 43158233 42267936 40227986 40268031 40418478 WWWW From MCD at goshenarc.org Sun Dec 4 01:50:21 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sat, 03 Dec 2005 20:50:21 -0500 Subject: [MCD] SWOMCD Message-ID: <200512040148.jB41mWVF013748@mail.goshen.edu> ACUS11 KWNS 040147 SWOMCD SPC MCD 040147 COR MDZ000-VAZ000-PAZ000-WVZ000-OHZ000-KYZ000-INZ000-040700- MESOSCALE DISCUSSION 2518 NWS STORM PREDICTION CENTER NORMAN OK 0747 PM CST SAT DEC 03 2005 AREAS AFFECTED...SRN IND/SRN OH/NRN KY/WV/WRN MD/NRN VA CONCERNING...FREEZING RAIN AND SLEET VALID 040147Z - 040700Z CORRECTED FOR NASHVILLE SOUNDING ...AREAS OF FZRA AND SLEET LIKELY THIS EVENING AND OVERNIGHT OVER PORTIONS OF THE OH VALLEY INTO THE CNTRL APPALACHIANS... ELEVATED CONVECTION/OVERRUNNING PCPN IS ALREADY MOVING NORTH OF THE OH RIVER...WHERE SFC TEMPS ARE AT OR BELOW FREEZING. WARMER TEMPERATURES WITHIN THE 750-800MB LAYER PER 00Z SOUNDINGS ARE RESULTING IN FREEZING RAIN ACROSS SRN IND/SRN OH. LARGE SCALE ASCENT WILL INCREASE AHEAD OF MID LEVEL SHORTWAVE NOW OVER THE UPPER MIDWEST. LATEST VAD WIND DATA FROM LOUISVILLE AND JACKSON KY INDICATE AT LEAST A 40-45 KT LLJ AROUND THE 1-2 KM AGL LAYER WITH 50 KT OBSERVED AT 850MB ON THE 00Z NASHVILLE SOUNDING. THE LLJ /850MB FLOW/ IS FORECAST TO INCREASE TO NEARLY 70KT BY 06Z WHICH WILL MAINTAIN STRONG WAA/ISENTROPIC LIFT ACROSS SRN OH/WV THIS EVENING. AMBIENT AIRMASS AT THE SFC IS VERY DRY...WITH DEWPOINTS IN THE TEENS IN MANY LOCATIONS. ALL THE SHORT TERM MODELS ARE TOO SLOW WITH BREAKING OUT PRECIPITATION GIVEN CURRENT TRENDS. HOWEVER RUC/NAM PTYPE ALGORITHMS DO AGREE THAT FZRA POSSIBLY MIXING WITH SLEET WILL DEVELOP ACROSS MUCH OF WV/NWRN VA/SRN OH AND POSSIBLY INTO SW PA THROUGH 04-06Z. FORECAST SOUNDINGS SUGGEST SOME OF THE HEAVIEST FZRA WILL LIKELY FALL AFTER 06Z ACROSS WV/NRN VA...WITH A STRONG INVERSION /+2 TO +4C/ NOTED IN THE 850-700MB LAYER ATOP A SUBFREEZING SFC AIRMASS. ..TAYLOR.. 12/04/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...CTP...LWX...RNK...PBZ...RLX...CLE...JKL...ILN...LMK...IWX...IND...PAH... 37467937 38178286 38498735 39488753 40328719 40157975 39767751 38517797 WWWW From MCD at goshenarc.org Sun Dec 4 03:38:25 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sat, 03 Dec 2005 22:38:25 -0500 Subject: [MCD] SWOMCD Message-ID: <200512040336.jB43aYw8028052@mail.goshen.edu> ACUS11 KWNS 040336 SWOMCD SPC MCD 040335 TNZ000-ALZ000-MSZ000-ARZ000-LAZ000-040530- MESOSCALE DISCUSSION 2521 NWS STORM PREDICTION CENTER NORMAN OK 0935 PM CST SAT DEC 03 2005 AREAS AFFECTED...SWRN TN...SERN AR...NRN/CENTRAL MS...SWRN/SRN MIDDLE TN CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 040335Z - 040530Z CONVECTION APPEARS TO DEVELOPING ALONG THE SEWD MOVING FRONT OVER EXTREME NWRN MS...AND OVER PARTS OF SWRN AR. WW WILL LIKELY BE NEEDED BY 04Z. AIRMASS AHEAD OF THE FRONT IS WARM/MOIST WITH TEMPERATURES NEAR 70F AND DEW POINTS OF 60-65F. STRONG WSWLY WINDS ALOFT /500 MB FLOW OF 50-70 KT/ AND VEERING PROFILES IN THE LOWEST 1.5-2 KM AGL ARE CREATING A FAVORABLE ENVIRONMENT FOR ROTATING STORMS GIVEN PERSISTENT UPDRAFTS. 00Z ETA AND 02Z RUC BOTH INDICATE ADDITIONAL THUNDERSTORM DEVELOPMENT ALONG THE FRONT INTO THE OVERNIGHT HOURS. A NEW WATCH WILL LIKELY BE NEEDED TO BE ISSUED BY 04Z. ..WEISS.. 12/04/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...OHX...BMX...HUN...MEG...JAN...LZK...SHV... 33219334 34339117 35248958 35668906 35698807 35568749 35408686 34828708 34138765 33668810 32719031 31959268 31989328 32289373 32899398 WWWW From MCD at goshenarc.org Sun Dec 4 05:41:37 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sun, 04 Dec 2005 00:41:37 -0500 Subject: [MCD] SWOMCD Message-ID: <200512040539.jB45dmCk009703@mail.goshen.edu> ACUS11 KWNS 040539 SWOMCD SPC MCD 040538 VAZ000-TNZ000-KYZ000-040745- MESOSCALE DISCUSSION 2522 NWS STORM PREDICTION CENTER NORMAN OK 1138 PM CST SAT DEC 03 2005 AREAS AFFECTED...S CNTRL/SERN KY...NRN MIDDLE/NERN TN CONCERNING...SEVERE THUNDERSTORM WATCH 888... VALID 040538Z - 040745Z A BAND OF STRONG/SEVERE ELEVATED THUNDERSTORMS IS MOVING RAPIDLY EWD ACROSS NRN TN...IN ADVANCE OF A STRONG UPPER LEVEL SHORT WAVE TROUGH MOVING ACROSS THE MIDDLE MS VALLEY. WATER VAPOR IMAGERY SHOWS VERY PRONOUNCED DRYING/SUBSIDENCE ADVANCING INTO THE LOWER PARTS OF THE OHIO AND TN RIVER VALLEYS WITH LARGE SCALE ASCENT IMMEDIATELY DOWNSTREAM OVER PARTS OF KY AND TN. THE SYNOPTIC SCALE LIFT APPEARS CO-LOCATED WITH ZONE OF FORCED ASCENT ALONG THE SURFACE COLD FRONT...ENHANCING THUNDERSTORM ACTIVITY DESPITE MARGINAL ELEVATED INSTABILITY AOB 600 J/KG PER LATEST RUC SOUNDING. LARGE HAIL WILL BE THE PRIMARY SEVERE THREAT WITH THE STRONGEST CELLS. ADDITIONAL CONVECTION CONTINUES TO MOVE RAPIDLY EWD ACROSS SOUTH CENTRAL/SERN KY WHERE LOW LEVEL WARM ADVECTION ASSOCIATED WITH THE 50-60 KT LOW LEVEL JET LOCATED ACROSS TN INTO KY. MARGINALLY SEVERE HAIL REMAINS POSSIBLE ACROSS THIS AREA. ..WEISS.. 12/04/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MRX...JKL...LMK...OHX... 37358554 37448351 36008330 35838517 35858649 35898778 WWWW From MCD at goshenarc.org Sun Dec 4 06:07:01 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sun, 04 Dec 2005 01:07:01 -0500 Subject: [MCD] SWOMCD Message-ID: <200512040605.jB465DMt019161@mail.goshen.edu> ACUS11 KWNS 040604 SWOMCD SPC MCD 040604 NYZ000-NJZ000-PAZ000-MDZ000-DCZ000-VAZ000-WVZ000-OHZ000-041030- MESOSCALE DISCUSSION 2523 NWS STORM PREDICTION CENTER NORMAN OK 1204 AM CST SUN DEC 04 2005 AREAS AFFECTED...NRN WV/NRN VA/MD/PA/SRN NY/NRN NJ CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION VALID 040604Z - 041030Z POTENTIAL FOR SLEET/FREEZING RAIN AND SOME ICE ACCUMULATION WILL EXIST OVERNIGHT FROM NRN WV INTO WRN/CNTRL MD...SRN PA...AND PERHAPS FAR NRN VA. FURTHER NORTH...MAINLY LIGHT/MDT SNOW WILL SPREAD EWD ACROSS MUCH OF PA AND FAR SRN NY OVERNIGHT. WATER VAPOR IMAGERY DEPICTS LOW AMPLITUDE IMPULSE PROGRESSING EWD ACROSS THE OHIO/TENNESSEE VALLEYS...WITH ASSOCIATED FORCING FOR ASCENT AND WARM AIR ADVECTION/MOISTURE TRANSPORT RESULTING IN EWD SPREAD OF PRECIPITATION ACROSS OH/WV INTO PA/NRN VA/MD AT THIS TIME. ATTRIBUTABLE TO 50-60 KT LOW LEVEL JET /AS SAMPLED BY CHARLESTON WV AND STERLING VA WSR-88D VADS/...21Z SREF GUIDANCE/03Z RUC FCST SOUNDINGS SUGGEST ELEVATED WARM LAYER WILL BE MAINTAINED ABOVE SHALLOW COLD BOUNDARY LAYER. THIS SCENARIO WILL BE SUPPORTIVE OF FREEZING RAIN AND/OR SLEET WHERE SUB 32F SFC TEMPS ARE MAINTAINED...WHICH IS LIKELY ACROSS SRN PA...AND MUCH OF MD/FAR NRN VA PRIMARILY NW OF I-95 AND ALONG/NORTH OF I-66. FURTHER NORTH...SUFFICIENTLY COLD PROFILES WILL FAVOR LIGHT/MDT SNOW AS PREDOMINANT PRECIP TYPE ACROSS THE BULK OF PA INTO SRN NY OVERNIGHT. ALTHOUGH SNOW RATES SHOULD GENERALLY BE LESS THAN 1 IN/HR...CONVECTIVE ENHANCEMENT COULD YIELD LOCALLY HIGHER BURSTS MAINLY ACROSS CNTRL/SRN PA. OBSERVATIONAL TRENDS/SHORT TERM MODEL GUIDANCE SUGGEST LIGHT/MDT SNOW SHOULD SPREAD EWD INTO SE NY/NRN NJ BY 12Z. ..GUYER.. 12/04/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...OKX...ALY...PHI...BGM...BUF...CTP...LWX...PBZ...RLX...CLE... 42437502 42107429 41277422 40727454 40387505 39577628 38877714 38587875 38297997 38608044 39478084 41588037 42307898 WWWW From MCD at goshenarc.org Sun Dec 4 08:03:17 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sun, 04 Dec 2005 03:03:17 -0500 Subject: [MCD] SWOMCD Message-ID: <200512040801.jB481SrT024812@mail.goshen.edu> ACUS11 KWNS 040800 SWOMCD SPC MCD 040800 GAZ000-TNZ000-ALZ000-MSZ000-040930- MESOSCALE DISCUSSION 2524 NWS STORM PREDICTION CENTER NORMAN OK 0200 AM CST SUN DEC 04 2005 AREAS AFFECTED...NRN LA...SERN AR...N CNTRL MS...NRN AND CNTRL AL AND SERN TN CONCERNING...TORNADO WATCH 889... VALID 040800Z - 040930Z NRN PORTION OF SQUALL LINE FROM SERN TN THROUGH NERN AL IS EXPECTED TO GRADUALLY WEAKEN AS IT MOVES INTO NWRN GA. THE SWRN TWO THIRDS OF THE LINE SHOULD CONTINUE TO DEVELOP SEWD. CONVECTIVE TRENDS WILL BE MONITORED FOR A POSSIBLE WW ACROSS PARTS OF CNTRL AL. EARLY THIS MORNING A SQUALL LINE EXTENDS FROM SERN TN SWWD THROUGH NRN AL AND FARTHER SW INTO N CNTRL MS. A WARM/WEDGE FRONT EXTENDS FROM CNTRL GA NWWD THROUGH NERN AL WHERE IT INTERSECTS THE SQUALL LINE. STRONGEST PORTION OF THE LINE IS CURRENTLY MOVING THROUGH NRN AL WHERE SIGNIFICANT WIND DAMAGE HAS BEEN REPORTED. HOWEVER...NRN THIRD OF THE LINE SHOULD WEAKEN AND BECOME MORE ELEVATED AS IT CROSSES THE WEDGE FRONT AND MOVES OVER A MUCH MORE STABLE BOUNDARY LAYER IN NRN GA AND SE TN WHERE TEMPERATURES ARE IN THE 40S. FARTHER SW STORMS WILL HAVE A MUCH WIDER WARM SECTOR TO TRAVERSE. HOWEVER...THE BOUNDARY LAYER FLOW IS EXPECTED TO GRADUALLY WEAKEN AND VEER WITH TIME AS THE LOW LEVEL JET SHIFTS NEWD AWAY FROM THE WARM SECTOR. THE WEAKENING AND VEERING BOUNDARY LAYER FLOW SHOULD RESULT IN A GRADUAL DECREASE IN CONVERGENCE AND MAY SERVE AS AN OVERALL LIMITING FACTOR FOR SEVERE WEATHER LATER THIS MORNING. NEVERTHELESS...CONVECTIVE TRENDS WILL CONTINUE TO BE MONITORED FOR A POSSIBLE WW OVER CNTRL AL AS STORMS APPROACH THE ERN EDGE OF WW 889. ..DIAL.. 12/04/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MRX...FFC...BMX...HUN...MEG...JAN... 32999102 33668842 34418663 35088570 34758452 33898467 32918602 32548860 32619089 WWWW From MCD at goshenarc.org Sun Dec 4 16:17:07 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sun, 04 Dec 2005 11:17:07 -0500 Subject: [MCD] SWOMCD Message-ID: <200512041615.jB4GFIY5023414@mail.goshen.edu> ACUS11 KWNS 041614 SWOMCD SPC MCD 041614 MSZ000-LAZ000-TXZ000-041815- MESOSCALE DISCUSSION 2526 NWS STORM PREDICTION CENTER NORMAN OK 1014 AM CST SUN DEC 04 2005 AREAS AFFECTED...SWRN/CENTRAL LA INTO CENTRAL MS CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 041614Z - 041815Z SEVERE TSTM THREAT EXPECTED TO SLOWLY INCREASE THROUGH THE LATE MORNING/EARLY AFTERNOON. WW MAY BE REQUIRED BY THE EARLY/MID AFTERNOON. THUNDERSTORMS HAVE INCREASED DURING THE PAST HOUR IN A NE-SW ORIENTED AXIS FROM NEAR HEZ TO JUST SOUTHWEST OF LCH. 12Z SOUNDINGS FROM JAN AND LCH INDICATE AIR MASS IS NOW ONLY WEAKLY CAPPED...IF AT ALL...GIVEN CURRENT SFC TEMPERATURES IN THE LOWER 70S F AND DEW POINTS IN THE UPPER 60S F. MLCAPES ARE NOW IN THE 500-1000 J/KG RANGE...BUT WILL INCREASE INTO THE 1000-1500 J/KG BY THE MID AFTERNOON GIVEN FURTHER HEATING. LATEST SURFACE ANALYSES INDICATES SURFACE WAVE FORMING ALONG THE FRONT NEAR LFK WHICH WILL LIKELY DEVELOP SLOWLY EWD INTO CENTRAL LA AS COLD FRONT CONTINUES MOVING SOUTHEAST. THOUGH LARGE SCALE ASCENT ACROSS THE REGION WILL REMAIN WEAK...LOW LEVEL FOCUS ALONG FRONT AND NEAR MESO LOW SHOULD SUPPORT INCREASED THUNDERSTORM DEVELOPMENT ACROSS THIS GENERAL REGION. SWLY WINDS ALOFT ARE NOT EXPECTED TO STRENGTHEN TODAY OVER THIS AREA...HOWEVER EFFECTIVE SHEAR IS STILL ANTICIPATED TO BE SUFFICIENT FOR SUPERCELLS/SMALL BOW ECHOES WITH STRONGER CELLS IF INSTABILITY CAN DEVELOP AS EXPECTED. THEREFORE...SEVERE THREAT SHOULD SLOWLY INCREASE THROUGH THE LATE MORNING AND WW MAY BECOME NECESSARY LATER TODAY. ..EVANS.. 12/04/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...JAN...LIX...LCH...SHV... 29649341 30149415 31079349 31709144 31928984 30858957 29999135 WWWW From MCD at goshenarc.org Sun Dec 4 18:27:36 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sun, 04 Dec 2005 13:27:36 -0500 Subject: [MCD] SWOMCD Message-ID: <200512041825.jB4IPiKx018784@mail.goshen.edu> ACUS11 KWNS 041825 SWOMCD SPC MCD 041824 GAZ000-ALZ000-042000- MESOSCALE DISCUSSION 2527 NWS STORM PREDICTION CENTER NORMAN OK 1224 PM CST SUN DEC 04 2005 AREAS AFFECTED...AL INTO WRN GA CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 041824Z - 042000Z THE THREAT OF ISOLATED LARGE HAIL AND DAMAGING WINDS SHOULD INCREASE ALONG AND SOUTH OF SURFACE FRONT ACROSS THE AREA THIS AFTERNOON. TRENDS ARE BEING MONITORED FOR A WW. SATELLITE IMAGERY AND 18Z SURFACE ANALYSES INDICATE STRONG TEMPERATURE/HEATING GRADIENT ACROSS CENTRAL AL INTO NRN/CENTRAL GA. WELL DEFINED SURFACE FRONT IS EXPECTED TO CONTINUE SHIFTING SLOWLY SSEWD THROUGH THE DAY...WITH TEMPERATURES APPROACHING 80F TO ITS SOUTH. REGION REMAINS ALONG NERN EXTENT OF PRIMARY LOW LEVEL MOISTURE AXIS EXTENDING OUT OF THE LOWER MS RIVER VALLEY WITH SURFACE DEW POINTS IN THE LOWER 60S F. THIS IS LIMITING AVAILABLE INSTABILITY WITH CURRENT MLCAPES LESS THAN 1000 J/KG. HOWEVER... STRONG HEATING WITHIN WARM SECTOR WILL STEEPEN LOW LEVEL LAPSE RATES AND DEEP LAYER SHEAR REMAINS MORE THAN ADEQUATE FOR ORGANIZED STORMS INCLUDING SUPERCELLS/SMALL BOW ECHOES. THE POTENTIAL FOR ORGANIZED/SUSTAINED UPDRAFTS AND STEEP LOW LEVEL LAPSE RATES MAY OVERCOME LIMITED INSTABILITY AND SUPPORT MARGINALLY SEVERE HAIL AND ISOLATED DAMAGING WINDS. SEVERE THUNDERSTORM WATCH BEING CONSIDERED FOR PART OF THIS REGION. ..EVANS.. 12/04/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...FFC...TAE...BMX...MOB... 33338829 34098426 32818350 31918507 31398825 WWWW From MCD at goshenarc.org Sun Dec 4 20:14:28 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sun, 04 Dec 2005 15:14:28 -0500 Subject: [MCD] SWOMCD Message-ID: <200512042012.jB4KCbnM010778@mail.goshen.edu> ACUS11 KWNS 042011 SWOMCD SPC MCD 042011 ALZ000-MSZ000-LAZ000-TXZ000-042215- MESOSCALE DISCUSSION 2528 NWS STORM PREDICTION CENTER NORMAN OK 0211 PM CST SUN DEC 04 2005 AREAS AFFECTED...FAR SERN TX...LA...CENTRAL MS CONCERNING...SEVERE THUNDERSTORM WATCH 890... VALID 042011Z - 042215Z SEVERE THUNDERSTORMS WILL CONTINUE DEVELOPING WEST TO EAST ACROSS WW INTO THE EARLY EVENING. CONTINUE VALID PORTION OF WW. 19Z SURFACE ANALYSIS INDICATES SURFACE COLD FRONT HAS PROGRESSED SOUTH-SOUTHEASTWARD THIS AFTERNOON AND EXTENDS FROM NEAR MEI SWWD TO JUST OFF THE FAR SOUTHEAST TX COAST. INTERMITTENT SUPERCELL AND SMALL BOW ECHO STRUCTURES HAVE DEVELOPED ALONG BROKEN LINE OF STORMS NOW EXTENDING FROM CENTRAL LA INTO FAR SERN TX. AIR MASS REMAINS MODERATELY UNSTABLE FROM THE LOWER SABINE RIVER INTO CENTRAL LA WHERE RICHER GULF MOISTURE AND WARMER TEMPERATURES HAVE DEVELOPED. SURFACE-BASED CAPES OVER THIS AREA ARE CURRENTLY IN EXCESS OF 1000 J/KG...WITH MORE MARGINAL INSTABILITY NOW INTO CENTRAL MS. SHEAR ACROSS THE WHOLE REGION REMAINS QUITE STRONG...WITH EFFECTIVE SHEAR FROM 40-50 KT ACCORDING TO REGIONAL VWP/S. SEASONABLY COOL MID LEVEL TEMPERATURES WILL SUSTAIN A THREAT OF LARGE HAIL...ESPECIALLY WITHIN SWRN PORTION OF WW WHERE GREATER INSTABILITY SHOULD SUPPORT HAIL TO GOLF BALL SIZE IN THE STRONGER CORES. THE THREAT OF MARGINALLY SEVERE HAIL WILL ALSO CONTINUE BEHIND SURFACE COLD FRONT ACROSS NORTHERN PORTIONS OF WW /AND ADJACENT AREAS/ ALONG NOSE OF SWLY 35-40 KT LLJ. DAMAGING WINDS WILL ALSO REMAIN A HAZARD AS SMALL LINES EVOLVE IN A MORE N-S ORIENTATION ALONG AND AHEAD OF THE FRONT. ..EVANS.. 12/04/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...BMX...MOB...JAN...LIX...LCH...SHV... 28729404 30529398 33568824 31318833 WWWW From MCD at goshenarc.org Sun Dec 4 21:33:26 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sun, 04 Dec 2005 16:33:26 -0500 Subject: [MCD] SWOMCD Message-ID: <200512042131.jB4LVZZw015501@mail.goshen.edu> ACUS11 KWNS 042131 SWOMCD SPC MCD 042130 SCZ000-GAZ000-ALZ000-042300- MESOSCALE DISCUSSION 2529 NWS STORM PREDICTION CENTER NORMAN OK 0330 PM CST SUN DEC 04 2005 AREAS AFFECTED...CENTRAL AND NRN AL/GA INTO CENTRAL SC CONCERNING...SEVERE THUNDERSTORM WATCH 891... VALID 042130Z - 042300Z THREAT FOR SEVERE THUNDERSTORMS...INCLUDING ISOLATED SUPERCELLS...EXPECTED TO CONTINUE ACROSS WW. ISOLATED SEVERE THREAT ALSO EXPECTED TO PERSIST JUST EAST OF WW ACROSS THE SAVANNAH RIVER VALLEY. CONTINUE WW. THOUGH LARGE SCALE ASCENT REMAINS WEAK ACROSS THE REGION...SEASONABLY WARM/MOIST BOUNDARY LAYER HAS DEVELOPED AHEAD OF A COLD FRONT NOW MOVING SEWD ACROSS NRN GA INTO CENTRAL AL. DEW POINTS REMAIN IN THE LOWER 60S OVER MUCH OF THE SEVERE TSTM WATCH...WITH AXIS OF NEAR 60F DEW POINTS SPREADING INTO AGS DURING THE PAST HOUR OR TWO. DEEP LAYER SHEAR REMAINS QUITE STRONG WITH EFFECTIVE SHEAR FROM 45-55 KT ACROSS THE REGION...AND WILL SUSTAIN A FEW SUPERCELLS WITH PRIMARY THREATS OF LARGE HAIL/DAMAGING WINDS. SHEAR AND INSTABILITY PARAMETERS INDICATE THE SEVERE THREAT WILL LIKELY CONTINUE AHEAD OF THE COLD FRONT INTO E-CENTRAL GA/FAR WRN SC THROUGH SUNSET. WE WILL NEED TO MONITOR THIS AREA INTO THE EARLY EVENING FOR AN ADDITIONAL WW. ..EVANS.. 12/04/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...CHS...CAE...GSP...FFC...BMX...HUN...MOB... 31668818 33848766 34368197 33658077 32208266 WWWW From MCD at goshenarc.org Sun Dec 4 23:48:18 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sun, 04 Dec 2005 18:48:18 -0500 Subject: [MCD] SWOMCD Message-ID: <200512042346.jB4NkQMh013883@mail.goshen.edu> ACUS11 KWNS 042345 SWOMCD SPC MCD 042345 ALZ000-FLZ000-MSZ000-LAZ000-050145- MESOSCALE DISCUSSION 2530 NWS STORM PREDICTION CENTER NORMAN OK 0545 PM CST SUN DEC 04 2005 AREAS AFFECTED...SE LA...SRN MS...SRN AL...FAR WRN FL PANHANDLE CONCERNING...SEVERE THUNDERSTORM WATCH 890... VALID 042345Z - 050145Z AN ISOLATED SEVERE POTENTIAL MAY CONTINUE AS A CONVECTIVE CLUSTER MOVES EWD ACROSS SRN MS AND SRN AL THIS EVENING. A REPLACEMENT WW MAY BE REQUIRED ACROSS THE REGION. SFC ANALYSIS CURRENTLY SHOWS A COLD FRONT EXTENDING ENEWD JUST NORTH OF A LINE FROM NEAR BATON ROUGE LA TO NEAR HATTIESBURG MS TO MONTGOMERY AL. SFC DEWPOINTS SOUTH OF THE FRONT ARE IN THE LOWER TO MID 60S F AND DEWPOINTS MAY INCREASE OVER THE NEXT FEW HOURS DUE TO SLY WINDS. THIS COMBINED WITH LOW-LEVEL CONVERGENCE ALONG THE BOUNDARY MAY ALLOW A BOW ECHO AND CONVECTIVE CLUSTER CURRENTLY ALONG THE MS-LA STATE-LINE TO CONTINUE FOR 3 TO 5 MORE HOURS. AS A RESULT...THE POTENTIAL FOR SEVERE STORMS MAY INCREASE OVER FAR SRN MS AND SRN AL INTO THE FL PANHANDLE. 0-6 KM SHEAR VALUES AROUND 45 KT WITH INCREASING LOW-LEVEL FLOW DUE TO THE STRENGTHENING LOW-LEVEL JET SHOULD BE SUFFICIENT FOR AT LEAST A MARGINAL SEVERE THREAT WITH ISOLATED WIND DAMAGE AND HAIL POSSIBLE WITH THE STRONGER CELLS. HOWEVER...WITH THE LOSS OF DAYTIME HEATING...THE MAGNITUDE OF THE SEVERE THREAT REMAINS QUESTIONABLE. ..BROYLES.. 12/04/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...BMX...MOB...JAN...LIX...LCH... 30689171 31379055 31958851 32078712 31598652 30918642 30118705 29798923 29869132 30029151 WWWW From MCD at goshenarc.org Mon Dec 5 00:38:15 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sun, 04 Dec 2005 19:38:15 -0500 Subject: [MCD] SWOMCD Message-ID: <200512050036.jB50aP2x006103@mail.goshen.edu> ACUS11 KWNS 050035 SWOMCD SPC MCD 050035 NYZ000-050630- MESOSCALE DISCUSSION 2531 NWS STORM PREDICTION CENTER NORMAN OK 0635 PM CST SUN DEC 04 2005 AREAS AFFECTED...NRN NY CONCERNING...HEAVY SNOW VALID 050035Z - 050630Z ...SNOW RATES WILL BE AT LEAST 2 INCHES PER HOUR WITHIN MOST INTENSE PORTIONS OF LAKE EFFECT BAND DOWNWIND OF LAKE ONTARIO... LOCAL RADAR LOOPS INDICATE HEAVY SNOW IS ONGOING ACROSS OSWEGO AND LEWIS COUNTIES IN NRN NY SOUTH OF WATERTOWN. 00Z SOUNDING FROM BUFFALO INDICATES A FAVORABLE UNIDIRECTIONAL WIND PROFILE WITH WESTERLIES INCREASING TO AROUND 40-45 KT NEAR 700MB. WINDS WITHIN THE 850-700MB LAYER WILL CHANGE LITTLE IN DIRECTION OVER THE NEXT FEW HOURS...AND THIS WILL MAINTAIN A SINGLE BUT INTENSE BAND OF HEAVY SNOW. FORECAST GUIDANCE FROM THE SHORT TERM MODELS SUGGESTS THE BAND MAY FLUCTUATE A LITTLE TO THE NORTH OR SOUTH...BUT BASICALLY WILL REMAIN OVER OSWEGO/SRN LEWIS COUNTIES...AND POSSIBLY NRN ONEIDA. THE RUC AND 4KM WRF/NMM BOTH HINT THAT HEAVY SNOW BANDS WILL PERSIST THROUGH THE OVERNIGHT HOURS. ..TAYLOR.. 12/05/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...BTV...ALY...BGM...BUF... 43157632 43287745 43837723 44317513 44087418 42987451 42927487 WWWW From MCD at goshenarc.org Mon Dec 5 04:47:19 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sun, 04 Dec 2005 23:47:19 -0500 Subject: [MCD] SWOMCD Message-ID: <200512050445.jB54jUS0001649@mail.goshen.edu> ACUS11 KWNS 050444 SWOMCD SPC MCD 050443 GAZ000-ALZ000-050645- MESOSCALE DISCUSSION 2532 NWS STORM PREDICTION CENTER NORMAN OK 1043 PM CST SUN DEC 04 2005 AREAS AFFECTED...ERN AL...WRN AND CNTRL GA CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 050443Z - 050645Z AN ISOLATED WIND DAMAGE THREAT MAY EXIST AS A BOW ECHO MOVES EWD ACROSS ERN AL INTO WRN GA OVER THE NEXT FEW HOURS. A WW MAY NEED TO BE ISSUED WITHIN THE NEXT HOUR. SFC ANALYSIS SHOWS A SLOW MOVING COLD FRONT EXTENDING ENEWD ACROSS SRN MS INTO CNTRL GA. SOUTH OF THE BOUNDARY...SFC DEWPOINTS ARE IN THE MID 60S F WITH A THERMAL AXIS EXTENDING NWD FROM THE FL PANHANDLE INTO ERN AL. IN ADDITION...LIFT AND VERTICAL SHEAR MAY INCREASE OVER THE NEXT FEW HOURS AS A SHORTWAVE EVIDENT ON WATER VAPOR IMAGERY AND 60 KT MID-LEVEL JET EVIDENT ON OBJECTIVE ANALYSIS APPROACHES CNTRL GA. AS THIS OCCURS...A GRADUAL INTENSIFICATION OF THE LINE WILL BE POSSIBLE AND ISOLATED WIND DAMAGE AND/OR HAIL MAY OCCUR. ..BROYLES.. 12/05/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...FFC...TAE...BMX...MOB... 31748522 31738598 31898635 32148642 32468625 32778542 33028433 33268340 33058305 32618297 32358339 31848437 WWWW From MCD at goshenarc.org Mon Dec 5 08:43:49 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 05 Dec 2005 03:43:49 -0500 Subject: [MCD] SWOMCD Message-ID: <200512050841.jB58fu55013517@mail.goshen.edu> ACUS11 KWNS 050839 SWOMCD SPC MCD 050839 GAZ000-FLZ000-ALZ000-050945- MESOSCALE DISCUSSION 2533 NWS STORM PREDICTION CENTER NORMAN OK 0239 AM CST MON DEC 05 2005 AREAS AFFECTED...FL PANHANDLE...EXTREME SERN AL AND EXTREME SWRN GA CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 050839Z - 050945Z THREAT FOR ISOLATED TORNADOES AND DAMAGING WIND MAY PERSIST OVER THE WRN AND CNTRL FL PANHANDLE INTO EXTREME SERN AL AND SWRN GA NEXT FEW HOURS. A WW MIGHT BE NECESSARY FOR THIS AREA. PRE-FRONTAL LINE OF STORMS EXTENDS FROM SWRN GA THROUGH SERN AL INTO THE WRN FL PANHANDLE. INDIVIDUAL CELLS WITHIN THIS LINE ARE MOVING NEWD WHILE THE LINE MOVES SLOWLY EAST. A SURFACE BOUNDARY EXTENDS FROM THE NERN GULF NWWD THROUGH THE CNTRL AND WRN FL PANHANDLE. TORNADO THREAT MAY BE AUGMENTED AS STORMS MOVE NEWD WITHIN THE LINE AND INTERACT WITH THE BOUNDARY OVER THE FL PANHANDLE WHERE LOW LEVEL SHEAR/HELICITY IS LIKELY ENHANCED. ACTIVITY WILL LIKELY BECOME MORE ELEVATED AS IT CROSSES DEEPER INTO THE LOWER THETA-E AIR N OF THE BOUNDARY ACROSS SWRN GA. ..DIAL.. 12/05/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...TAE...MOB... 30488641 31298563 31608482 30958452 30278577  From MCD at goshenarc.org Mon Dec 5 12:58:50 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 05 Dec 2005 07:58:50 -0500 Subject: [MCD] SWOMCD Message-ID: <200512051256.jB5CuwMU005984@mail.goshen.edu> ACUS11 KWNS 051256 SWOMCD SPC MCD 051255 VAZ000-WVZ000-051700- MESOSCALE DISCUSSION 2534 NWS STORM PREDICTION CENTER NORMAN OK 0655 AM CST MON DEC 05 2005 AREAS AFFECTED...WRN/CNTRL VA AND FAR SE WV CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION VALID 051255Z - 051700Z SNOW IS EXPECTED TO DEVELOP/GRADUALLY INCREASE THIS MORNING ACROSS THE FAR SE WV/WRN VA APPALACHIANS INTO THE CNTRL VA PIEDMONT. IN SRN VA...INITIAL RAIN SHOULD BEGIN TO MIX WITH SNOW/SLEET BY 15Z-18Z. 12Z SURFACE/UPPER AIR ANALYSIS DEPICTS TIGHTENING BAROCLINIC ZONE ACROSS THE CNTRL APPALACHIANS REGION...WITH BROAD MOISTURE/ASCENT PLUME SPREADING NEWD ACROSS SRN VA AS LOW LEVEL CYCLONE GRADUALLY EVOLVES ALONG THE GA/SC BORDER. ALTHOUGH 35-40F SFC TEMPS ARE COMMON ACROSS MUCH OF WRN/CNTRL VA EARLY THIS MORNING...WITH SATURATION/TIGHTENING BAROCLINIC GRADIENT...THERMODYNAMIC PROFILES SHOULD COOL SUFFICIENTLY TO SUPPORT A RELATIVELY QUICK TRANSITION TO WET SNOW. THIS SCENARIO IS SUPPORTED BY MID LEVEL SATURATION/LOW LEVEL COOLING OBSERVED BETWEEN 00Z-12Z ROANOKE RAOBS...AS WELL AS SREF PRECIP-TYPE CONSENSUS AND 09Z RUC FCST SOUNDINGS. IN SRN VA...AFTER INITIAL BOUT OF RAIN...AFOREMENTIONED GUIDANCE SUGGESTS SLEET/SNOW SHOULD MIX IN BY MID/LATE MORNING ALONG A MARION-WYTHEVILLE-FARMVILLE-RICHMOND CORRIDOR. ..GUYER.. 12/05/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...AKQ...LWX...RNK...RLX...MRX... 38367818 38087744 37367727 36747905 36618002 36658192 37118194 37698089 WWWW From MCD at goshenarc.org Mon Dec 5 17:31:42 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 05 Dec 2005 12:31:42 -0500 Subject: [MCD] SWOMCD Message-ID: <200512051729.jB5HTqsD032086@mail.goshen.edu> ACUS11 KWNS 051728 SWOMCD SPC MCD 051728 GAZ000-FLZ000-ALZ000-051800- MESOSCALE DISCUSSION 2535 NWS STORM PREDICTION CENTER NORMAN OK 1128 AM CST MON DEC 05 2005 AREAS AFFECTED...ERN FL PANHANDLE INTO PARTS OF SWRN GA CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 051728Z - 051800Z ISOLATED SEVERE STORMS WILL BE POSSIBLE THIS AFTERNOON ACROSS THE ERN FL PANHANDLE INTO PARTS OF SWRN GA. IF THREAT APPEARS TO BECOME MORE WIDESPREAD...THEN A WW WOULD BE REQUIRED. REGIONAL RADARS SHOWED AN ISOLATED ROTATING STORM OVER LIBERTY COUNTY FL...WITH ADDITIONAL STORMS LOCATED ALONG/NEAR THE COLD FRONT FROM THE WRN FL PANHANDLE INTO SWRN GA. THE LIBERTY COUNTY STORM IS LOCATED IN THE WARM SECTOR WHERE SURFACE DEWPOINTS ARE MAINLY IN THE UPPER 60S. DESPITE WEAKER SURFACE WINDS/CONVERGENCE IN THIS REGION AHEAD OF THE FRONT...FAVORABLE DEEP LAYER AND LOW-LEVEL SHEAR /0-3 KM SRH NEAR 300 M2/S2/ VALUES CONTINUE TO SUPPORT ROTATING STORMS. MARGINAL INSTABILITY SHOULD...HOWEVER...LIMIT THE NUMBER OF STORMS THAT CAN ATTAIN PERSISTENT ROTATION AND ANY ATTENDANT SEVERE THREAT. ..PETERS.. 12/05/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...JAX...TAE... 29718626 30748540 31468450 31708367 31298291 30018327 29428415 29368524 WWWW From MCD at goshenarc.org Mon Dec 5 18:57:26 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 05 Dec 2005 13:57:26 -0500 Subject: [MCD] SWOMCD Message-ID: <200512051855.jB5ItZGK008668@mail.goshen.edu> ACUS11 KWNS 051854 SWOMCD SPC MCD 051854 NJZ000-PAZ000-DEZ000-MDZ000-VAZ000-DCZ000-WVZ000-060100- MESOSCALE DISCUSSION 2536 NWS STORM PREDICTION CENTER NORMAN OK 1254 PM CST MON DEC 05 2005 AREAS AFFECTED...MUCH OF VA/SE WV/NE MD AND THE ERN SHORE/DE/SRN NJ CONCERNING...HEAVY SNOW/WINTER PCPN TRENDS VALID 051854Z - 060100Z ...MODERATE TO HEAVY SNOW WILL CONTINUE ACROSS PORTIONS OF VA/WV...WITH SNOW RATES OF 1 TO 2 INCHES PER HOUR. SNOW WILL SPREAD INTO NRN VA AND MD THROUGH THE AFTN HOURS... LATEST WV LOOP SHOWS SHORT WAVE TROUGH NOW ACROSS OK/AR. THIS IMPULSE WILL TRACK INTO THE TN VALLEY/SRN APPALACHIANS LATER TONIGHT. SFC LOW IS NOW ANALYZED NEAR ATHENS GA...WITH A WARM FRONT LIFTING NWD ACROSS THE SC PIEDMONT. ETA HAS TRENDED TOWARD THE GFS SOLNS FOR THE PAST FEW RUNS...WITH THE SFC LOW TRACK CLOSER TO HATTERAS...BEFORE MOVING OUT TO SEA. WITH THIS SETUP...BAND OF HEAVIEST PCPN ASSOCIATED WITH UPPER DEFORMATION ZONE WILL BE FOCUSED ACROSS CNTRL INTO NE VA...EVENTUALLY SPREADING INTO SRN NJ/NE MD/DE BY EARLY EVENING. LATEST LOCAL/COMPOSITE RADAR ANIMATIONS SHOW A FAIRLY NARROW BAND OF MODERATE TO HEAVY SNOW EXTENDING FROM BLF/HSP/FVX/RIC. CLOSER TO THE VA/NC BORDER...TEMPS ARE WARM ENOUGH FOR RAIN. 17Z SPECIAL SOUNDINGS FROM DULLES AND NE OF BWI INDICATE THAT WHILE THE THERMODYNAMIC PROFILE IS COLD ENOUGH FOR SNOW...THERE IS STILL SOME DRY AIR THROUGH THE COLUMN. FORECAST SOUNDINGS SUGGEST SATURATION SHOULD OCCUR WITHIN THE NEXT COUPLE OF HOURS WITH ACCUMULATING SNOWS AFTER 21-22Z...ACROSS THE DC/BALTIMORE METRO AREAS...AND CLOSER TO 06/00Z TOWARD DOV/PHL. SUSTAINED MID LEVEL WARM ADVECTION IN THE 700-850MB MAY ALLOW SNOW TO CHANGE TO A SLEET/SNOW MIX LATER THIS AFTN ACROSS PORTIONS OF CNTRL VA CURRENTLY EXPERIENCING SNOW. FORECAST SOUNDINGS ACROSS NRN VA/SE WV/MD BECOME NEARLY ISOTHERMAL WITH STRONG ASCENT IN THE FAVORED DENDRITIC ZONE BY LATE AFTN/EVENING. THIS SHOULD SUPPORT MODERATE TO OCCASIONAL HEAVY SNOW RATES INTO THE EVENING. ..TAYLOR.. 12/05/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...PHI...AKQ...CTP...LWX...RNK...PBZ...RLX...MRX... 40487504 38638016 37228219 36658153 37407659 39307376 40007415 WWWW From MCD at goshenarc.org Mon Dec 5 20:42:48 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 05 Dec 2005 15:42:48 -0500 Subject: [MCD] SWOMCD Message-ID: <200512052040.jB5Keu1p008048@mail.goshen.edu> ACUS11 KWNS 052040 SWOMCD SPC MCD 052039 GAZ000-FLZ000-052215- MESOSCALE DISCUSSION 2537 NWS STORM PREDICTION CENTER NORMAN OK 0239 PM CST MON DEC 05 2005 AREAS AFFECTED...SRN GA/NRN FL CONCERNING...TORNADO WATCH 893... VALID 052039Z - 052215Z ISOLATED TORNADOES AND WIND DAMAGE REMAIN POSSIBLE ACROSS NRN FL AND SRN GA. AT 20Z...REGIONAL RADARS INDICATED THE STRONGEST STORMS WITH ROTATION WERE LOCATED OVER SRN GA IN CLINCH COUNTY...OVER LOWNDES COUNTY GA AND OFFSHORE OVER THE NERN GULF /60 W CTY/. THESE DISCRETE STORMS ARE MOVING NEWD AT 25-30 KT AND ARE LOCATED JUST EAST OF A LOW-TOPPED LEWP WHICH EXTENDED FROM SOUTH CENTRAL GA TO THE ERN FL PANHANDLE...JUST E OF TLH. LACK OF LIGHTNING WITH THE LEWP SUGGESTS THE STRONGEST STORMS WITH GREATEST SEVERE THREAT SHOULD REMAIN WITH THE DISCRETE ACTIVITY MOVING NEWD THROUGH THE MOISTURE/WEAK INSTABILITY AXIS OVER NWRN FL INTO SRN GA. DESPITE THE WEAK INSTABILITY...DEEP LAYER AND LOW-LEVEL SHEAR VALUES WILL CONTINUE TO SUPPORT A THREAT FOR ISOLATED TORNADOES AND/OR DAMAGING WINDS. A FEW STORMS MAY REMAIN STRONG ENOUGH TO RESULT IN A TORNADO THREAT EAST OF WW 893 INTO SERN GA/NERN FL. HOWEVER...GIVEN THE SMALL AREAL COVERAGE AND LIMITED THREAT...A NEW WW DOES NOT APPEAR LIKELY AT THIS TIME. ..PETERS.. 12/05/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...CHS...TBW...JAX...FFC...TAE... 29668497 30608375 31948306 32208239 31838181 30998160 30278172 29598232 29158321 WWWW From MCD at goshenarc.org Mon Dec 5 21:59:56 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 05 Dec 2005 16:59:56 -0500 Subject: [MCD] SWOMCD Message-ID: <200512052158.jB5Lw4CQ004999@mail.goshen.edu> ACUS11 KWNS 052157 SWOMCD SPC MCD 052157 FLZ000-GAZ000-052300- MESOSCALE DISCUSSION 2538 NWS STORM PREDICTION CENTER NORMAN OK 0357 PM CST MON DEC 05 2005 AREAS AFFECTED...SRN GA/NRN FL CONCERNING...TORNADO WATCH 893... VALID 052157Z - 052300Z ISOLATED TORNADOES AND/OR DAMAGING WINDS REMAIN POSSIBLE ACROSS VALID PART OF WW 893. LIGHTNING DATA/REGIONAL RADARS SUGGEST STRONGEST ACTIVITY IS LOCATED OFFSHORE OVER THE NERN GULF...WITH LINE OF THUNDERSTORMS MOVING EWD TOWARD THE NWRN FL GULF COAST /TAYLOR AND DIXIE COUNTIES/. RADAR DATA SHOWED EMBEDDED ROTATING STORMS OFFSHORE WITH THIS ACTIVITY...WHERE GREATEST CAPE WAS LOCATED. INSTABILITY IS WEAKER INLAND ACROSS NRN FL. THIS SHOULD LIMIT THE INLAND THREAT FOR ADDITIONAL SEVERE STORMS...EXCEPT ALONG THE COASTAL REGIONS WITH LAND FALLING STORMS. ..PETERS.. 12/05/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...TBW...JAX...TAE... 29798360 30488292 31158197 30228201 29578267 29228317 29248341 WWWW From MCD at goshenarc.org Mon Dec 5 23:19:06 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 05 Dec 2005 18:19:06 -0500 Subject: [MCD] SWOMCD Message-ID: <200512052317.jB5NHED0023745@mail.goshen.edu> ACUS11 KWNS 052316 SWOMCD SPC MCD 052316 FLZ000-060115- MESOSCALE DISCUSSION 2539 NWS STORM PREDICTION CENTER NORMAN OK 0516 PM CST MON DEC 05 2005 AREAS AFFECTED...COASTAL NW FL CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 052316Z - 060115Z ADDITIONAL WW NOT ANTICIPATED...BUT NARROW CORRIDOR OF SEVERE POTENTIAL MAY EXTEND SEWD ALONG FL GULF COAST AND ADJACENT WATERS...FROM WW 893 TO N OF PIE. STRONG/POSSIBLY SEVERE TSTMS OVER NERN GULF ARE EXPECTED TO MOVE INLAND AND WEAKEN...AS THEY ENCOUNTER INFLOW-LAYER AIR MASS THAT WILL STABILIZE BOTH WITH TIME AND WITH EWD EXTENT. SLGT POTENTIAL FOR DAMAGING WIND OR A TORNADO EXISTS OVER IMMEDIATE COASTAL AREAS...SE OF WW 893...FROM LEVY TO PASCO COUNTIES. VERTICAL SHEAR PROFILES -- ALREADY MARGINAL FROM TBW AREA SWD...ARE FCST TO WEAKEN WITH TIME ALONG ENTIRE W-CENTRAL/NW COAST OF FL AS BOUNDARY LAYER FLOW VEERS...SHRINKING 0-1 AND 0-3 KM AGL HODOGRAPHS. HOWEVER...THIS VEERING MAY ALLOW RELATIVELY BUOYANT BOUNDARY LAYER AIR NOW OFFSHORE TO ADVECT OVER COAST BEFORE PASSAGE OF PRIMARY CONVECTIVE BAND. MODIFIED RAOBS AND RUC SOUNDINGS INDICATE MLCAPES 200-500 J/KG ARE POSSIBLE BETWEEN CONVECTIVE BAND AND PASCO COUNTY THROUGH ABOUT 03Z. LEWP/BOW FORMATIONS NOW EVIDENT INVOF NARROW OFFSHORE CORRIDOR OF BUOYANCY MAY SURVIVE TO REACH COASTLINE BEFORE THEY WEAKEN. ..EDWARDS.. 12/05/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...TBW...JAX...TAE... 29308317 29538282 29488249 29058245 28608236 28238250 28188277 28278318 28508302 28668300 28778304 28818323 28948336 29168344 WWWW From MCD at goshenarc.org Tue Dec 6 00:29:47 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 05 Dec 2005 19:29:47 -0500 Subject: [MCD] SWOMCD Message-ID: <200512060027.jB60Rr91000449@mail.goshen.edu> ACUS11 KWNS 060027 SWOMCD SPC MCD 060026 ILZ000-IAZ000-MOZ000-KSZ000-NEZ000-060530- MESOSCALE DISCUSSION 2540 NWS STORM PREDICTION CENTER NORMAN OK 0626 PM CST MON DEC 05 2005 AREAS AFFECTED...SERN NEB/NERN KS/SRN IA/NRN MO CONCERNING...HEAVY SNOW VALID 060026Z - 060530Z ...BRIEF HEAVY/CONVECTIVE SNOW BURSTS ARE POSSIBLE IN ASSOCIATION WITH FAST MOVING SHORTWAVE TROUGH... LATE AFTN WATER VAPOR LOOPS CLEARLY SHOW SMALL BUT WELL DEFINED VORT MAX QUICKLY MOVING SEWD. THERE HAS BEEN A HISTORY OF MODERATE TO HEAVY SNOW RATES...WITH 20-40 MPH SFC WINDS AS THIS FEATURE MOVES BY. THE SNOW HAS LASTED JUST AN HOUR OR TWO IN MOST PLACES...WITH BRIEF HEAVY/CONVECTIVE SNOW BURSTS. PCPN WILL BE CLOSELY TIED TO UPPER FORCING...AND SINCE THE SYSTEM IS SO PROGRESSIVE...SIGNIFICANT SNOW ACCUMULATIONS ARE NOT EXPECTED. IN ADDITION...TEMPERATURES ARE FALLING SHARPLY...ON THE ORDER OF 12-15 DEGREES WITHIN AN HOUR. ..TAYLOR.. 12/06/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LSX...DVN...DMX...EAX...FSD...OAX...TOP...GID...LBF... 38949272 39829856 41509867 42349744 42139450 41799217 41269097 40259111 39279155 WWWW From MCD at goshenarc.org Tue Dec 6 01:31:56 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 05 Dec 2005 20:31:56 -0500 Subject: [MCD] SWOMCD Message-ID: <200512060130.jB61U3wm002064@mail.goshen.edu> ACUS11 KWNS 060129 SWOMCD SPC MCD 060129 MTZ000-WYZ000-IDZ000-060730- MESOSCALE DISCUSSION 2541 NWS STORM PREDICTION CENTER NORMAN OK 0729 PM CST MON DEC 05 2005 AREAS AFFECTED...WRN AND CNTRL MT CONCERNING...HEAVY SNOW AND NEAR BLIZZARD CONDITIONS VALID 060129Z - 060730Z ...MODERATE TO HEAVY SNOW WILL DEVELOP THIS EVENING INTO THE OVERNIGHT ACROSS CNTRL AND WRN MT WITH VERY STRONG POST FRONTAL WINDS CAUSING NEAR BLIZZARD CONDITIONS... UPPER LOW WILL MOVE SEWD ACROSS ALBERTA...ARRIVING AT THE INTERNATIONAL BORDER BY EARLY TUE MORNING. POTENT 120+KT JET STREAK WILL ALSO DIVE SWD ACROSS THE REGION. LARGE SCALE ASCENT WILL INCREASE IN RESPONSE TO STRONG CYCLONIC VORTICITY ADVECTION...RESULTING IN A PROLONGED PERIOD OF MODERATE TO HEAVY SNOW FOR THE DISCUSSION AREA. IN ADDITION...STRONG ARCTIC FRONT NOW FROM NEAR MSO TO SOUTH OF HLN WILL CONTINUE MOVING SWD THROUGH THE NIGHT. STRONG WINDS OF 20-40 MPH WITH HIGHER GUSTS WILL CREATE BLIZZARD CONDITIONS...ESPECIALLY IN AREAS WITH ONGOING MODERATE/HEAVY SNOW. ..TAYLOR.. 12/06/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...BYZ...RIW...TFX...MSO...OTX... 44631266 47241587 48731480 48571063 47250880 45210851 45020871 WWWW From MCD at goshenarc.org Wed Dec 7 11:27:51 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 07 Dec 2005 06:27:51 -0500 Subject: [MCD] SWOMCD Message-ID: <200512071125.jB7BPuSw023709@mail.goshen.edu> ACUS11 KWNS 071125 SWOMCD SPC MCD 071124 TXZ000-071630- MESOSCALE DISCUSSION 2542 NWS STORM PREDICTION CENTER NORMAN OK 0524 AM CST WED DEC 07 2005 AREAS AFFECTED...N CNTRL TX CONCERNING...WINTER MIXED PRECIPITATION VALID 071124Z - 071630Z PRECIPITATION IS EXPECTED TO GRADUALLY INCREASE ACROSS N CNTRL TX THROUGH THE MORNING. LIGHT FREEZING RAIN WILL BE POSSIBLE OVER THE WRN HALF OF N CNTRL TX BY MID MORNING. THE FREEZING RAIN MAY BEGIN TO MIX WITH SLEET OR SNOW BY LATE MORNING OR AFTERNOON. A COLD FRONT EXTENDS FROM SRN AR INTO N CNTRL TX NEAR FORT WORTH THEN SWWD INTO THE BIG BEND AREA. THIS FRONT WILL MOVE SEWD TODAY...ALLOWING COLD ARCTIC HIGH PRESSURE TO CONTINUE BUILDING INTO TX. POST FRONTAL WET BULB TEMPERATURES ARE WELL BELOW FREEZING OVER THE WRN PARTS OF N CNTRL TX. A 20-30 KT LOW LEVEL JET WILL PERSIST OVER CNTRL TX INTO THE AFTERNOON. THIS WILL MAINTAIN ISENTROPIC ASCENT AND WARM ADVECTION WITHIN THE 1-3 KM LAYER. THIS ASCENT IS ALREADY CONTRIBUTING TO AN INCREASE IN STRATUS AND PRECIPITATION OVER THE SRN HALF OF N CNTRL TX. OWING TO THE RELATIVE DRY BOUNDARY LAYER...MUCH OF THIS ACTIVITY IS NOT LIKELY REACHING THE GROUND IN POST FRONTAL REGION. EVAPORATIVE COOLING WILL EVENTUALLY SATURATE THE LAYER BELOW 3 KM AND MAINTAIN SURFACE TEMPERATURES BELOW FREEZING OVER THE WRN HALF OF N CNTRL TX. RUC SOUNDINGS VALID FOR EARLY THIS MORNING SHOW A WARM LAYER AROUND 2 KM...AND THIS PROFILE WILL LIKELY SUPPORT FREEZING RAIN AS SURFACE TEMPERATURES WET BULB BELOW ZERO. THIS WARM LAYER IS FORECAST TO GRADUALLY ERODE AS THE SUBZERO LAYER DEEPENS WITHIN THE POST FRONTAL ZONE. A CHANGEOVER OR MIX WITH SLEET AND SNOW WILL THEREFORE BE POSSIBLE. THE CHANGEOVER TO SNOW WILL BE MOST LIKELY OVER NWRN PARTS OF N CNTRL TX BY LATE MORNING...ESPECIALLY IF VERTICAL MOTION IS DEEP ENOUGH TO SATURATE THE LAYERS BELOW -10C WHERE DENDRITIC GROWTH IS FAVORED. BOTH ETA AND RUC FORECAST SOUNDINGS SHOW A SHALLOW UNSTABLE LAYER DEVELOPING BETWEEN 3 AND 5 KM BY MID-DAY...WHICH MAY CONTRIBUTE TO SOME CONVECTIVE ENHANCEMENT TO THE PRECIPITATION. ..DIAL.. 12/07/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...SHV...FWD...SJT... 33689593 32529547 32059669 31509814 31139904 31819913 33309755 WWWW From MCD at goshenarc.org Wed Dec 7 18:51:05 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 07 Dec 2005 13:51:05 -0500 Subject: [MCD] SWOMCD Message-ID: <200512071849.jB7InDen019718@mail.goshen.edu> ACUS11 KWNS 071848 SWOMCD SPC MCD 071848 OKZ000-TXZ000-080045- MESOSCALE DISCUSSION 2543 NWS STORM PREDICTION CENTER NORMAN OK 1248 PM CST WED DEC 07 2005 AREAS AFFECTED...CNTRL/NCNTRL TX...SRN OK CONCERNING...WINTER MIXED PRECIPITATION VALID 071848Z - 080045Z ...A WINTRY MIX OF PRECIPITATION WILL CONTINUE ACROSS THE SRN PLAINS. FREEZING RAIN WILL CONTINUE WELL INTO THE EVENING HOURS ACROSS PORTIONS OF THE DFW METROPLEX...SWD ALONG I-35... STRONG LOW LEVEL COLD ADVECTION CONTINUES ACROSS THE HILL COUNTRY THIS AFTERNOON...WITH SUB FREEZING TEMPERATURES NOW OBSERVED OVER MOST OF THE ESCARPMENT WEST OF I-35. SUSTAINED WARM ADVECTION ATOP THIS SHALLOW AIRMASS HAS AIDED RENEWED SHOWER DEVELOPMENT AS PRECIPITATION/SHALLOW CONVECTION EXPANDS NWD ACROSS NCNTRL TX INTO SRN OK. THESE TRENDS WILL LIKELY PERSIST WELL INTO THE EVENING HOURS BEFORE SUBSIDENT...DRYING AIRMASS DEVELOPS AND SPREADS ACROSS NWRN TX. LATEST TRENDS...AND FORECAST SOUNDINGS SUGGEST FREEZING RAIN WILL BE THE GREATEST WINTER THREAT ALONG THE I-35 CORRIDOR FROM JUST NORTH OF AUS...INTO THE DFW METROPLEX. NWRN PORTIONS OF THE METROPLEX HAVE TRANSITIONED TO SLEET. HOWEVER DOWNSTREAM...VERTICAL PROFILES REMAIN FAVORABLE FOR A PROLONGED FREEZING RAIN EVENT THAT SHOULD GENERATE HOURLY FREEZING RAIN TOTALS ON THE ORDER OF .02 IN...ESPECIALLY FROM DALLAS COUNTY TO HILL COUNTY. FARTHER NORTH...LIGHT SNOW IS DEVELOPING/SPREADING NWD ACROSS SRN OK. THIS PRECIPITATION WILL GRADUALLY INCREASE IN INTENSITY AS EVENING APPROACHES...BUT SNOW RATES SHOULD REMAIN WELL LESS THAN 1IN/HR. ..DARROW.. 12/07/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...TSA...FWD...OUN...EWX... 32239822 33669868 35799632 35189551 32889606 32069656 30979711 30329772 30459838 31289825 WWWW From MCD at goshenarc.org Thu Dec 8 01:23:36 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 07 Dec 2005 20:23:36 -0500 Subject: [MCD] SWOMCD Message-ID: <200512080121.jB81Lfjh010535@mail.goshen.edu> ACUS11 KWNS 080121 SWOMCD SPC MCD 080121 MOZ000-OKZ000-KSZ000-NEZ000-080515- MESOSCALE DISCUSSION 2544 NWS STORM PREDICTION CENTER NORMAN OK 0721 PM CST WED DEC 07 2005 AREAS AFFECTED...ERN KS/FAR NE OK/WRN MO CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION VALID 080121Z - 080515Z AREA OF LIGHT/OCNLY MDT SNOW WILL CONTINUE TO TRANSITION EWD ACROSS E KS/FAR NE OK INTO WRN MO THIS EVENING. RATES MAY REACH 1 IN/HR ON A LOCALIZED BASIS. DEEP ASCENT CONTINUES TO SPREAD EWD ALONG THE MISSOURI VALLEY AMIDST STRONG DIFFERENTIAL CVA/ISENTROPIC LIFT REGIME AHEAD OF WRN NEB/WRN KS CLOSED LOW. LIGHT/OCNLY MDT SNOW HAS PERSISTED MUCH OF THE AFTERNOON ACROSS ERN KS INTO THE KC METRO AREA...WITH SOMEWHAT CONCENTRATED BAND OF RELATIVELY HEAVIER SNOWFALL ONGOING EARLY THIS EVENING FROM ALONG/EAST OF THE KS TURNPIKE INTO THE KC METRO AREA. 00Z TOPEKA RAOB/21Z RUC BASED FCST SOUNDINGS FEATURE DEEPLY SATURATED THERMODYNAMIC PROFILES...WITH AMPLE UVVS COINCIDENT WITH RELATIVELY DEEP/FAVORABLE DENDRITIC GROWTH ZONE. COLD ARCTIC AIRMASS WILL PROMOTE SNOW TO LIQUID WATER RATIOS OF 15:1 OR PERHAPS 20:1. ..GUYER.. 12/08/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...SGF...EAX...TSA...OAX...TOP...ICT... 38659636 39249616 40299522 40309462 40079344 39179359 37699438 36839476 36529501 36559615 38179647 WWWW From MCD at goshenarc.org Thu Dec 8 12:10:35 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 08 Dec 2005 07:10:35 -0500 Subject: [MCD] SWOMCD Message-ID: <200512081208.jB8C8enO007241@mail.goshen.edu> ACUS11 KWNS 081208 SWOMCD SPC MCD 081207 KYZ000-INZ000-ILZ000-TNZ000-MOZ000-ARZ000-081600- MESOSCALE DISCUSSION 2545 NWS STORM PREDICTION CENTER NORMAN OK 0607 AM CST THU DEC 08 2005 AREAS AFFECTED...NERN AR...NWRN TN...SERN MO...SRN IL...WRN KY AND SRN IND CONCERNING...WINTER MIXED PRECIPITATION VALID 081207Z - 081600Z MOSTLY LIGHT SNOW ALONG WITH A MIX OF SOME FREEZING RAIN AND SLEET SHOULD CONTINUE FROM NERN AR THROUGH SERN MO...NWRN TN...WRN KY AND SRN IL THIS MORNING. PRECIPITATION RATES SHOULD GRADUALLY INCREASE ACROSS PARTS OF SERN IL INTO SRN IN AND WRN KY BY LATE MORNING INTO THE AFTERNOON. EARLY THIS MORNING A SHORTWAVE TROUGH AND INTENSIFYING MID LEVEL JET WERE MOVING EWD TOWARD THE LOWER/MID MS VALLEY. AN AREA OF MOSTLY LIGHT SNOW WITHIN THE ZONE OF ASCENT DOWNSTREAM FROM THIS FEATURE EXTENDS FROM NERN AR NWD INTO MO. A SLY LOW LEVEL JET IS FORECAST TO STRENGTHEN OVER THE TN VALLEY LATER THIS MORNING IN ASSOCIATION WITH INCREASING FORCING FOR ASCENT ACCOMPANYING THE INTENSIFYING MID LEVEL JET. THIS SHOULD ENHANCE LOW LEVEL MOISTURE TRANSPORT AS WELL AS ISENTROPIC ASCENT OVER SWRN PARTS OF THE OH VALLEY LATE THIS MORNING AND ESPECIALLY INTO THE AFTERNOON. SNOWFALL RATES MAY INCREASE TO NEAR 1 INCH PER HOUR FROM SERN IL...SRN IND INTO PARTS OF NWRN KY BY EARLY AFTERNOON. RUC FORECAST SOUNDINGS SHOW PRESENCE OF A WARM LAYER AROUND 1 KM FROM WRN KY INTO SRN IL AND SRN IND. THE PRECIPITATION MAY BRIEFLY START OUT AS MOSTLY FREEZING RAIN IN THESE AREAS...BUT SHOULD TRANSITION TO SLEET AND SNOW AS TEMPERATURES GRADUALLY WET BULB TO NEAR AND BELOW ZERO. THE SNOW/SLEET/FREEZING RAIN TRANSITION LINE IS EXPECTED TO REMAIN FAIRLY NARROW...EXTENDING FROM EXTREME NERN AR THROUGH NWRN KY. ..DIAL.. 12/08/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LMK...OHX...IND...PAH...ILX...MEG...LSX...LZK...SGF... 35389202 37299066 38948802 39178657 38488563 37408590 36918704 36018928 34679132 WWWW From MCD at goshenarc.org Thu Dec 8 18:04:07 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 08 Dec 2005 13:04:07 -0500 Subject: [MCD] SWOMCD Message-ID: <200512081802.jB8I2DCn008979@mail.goshen.edu> ACUS11 KWNS 081800 SWOMCD SPC MCD 081800 WVZ000-OHZ000-KYZ000-INZ000-ILZ000-090000- MESOSCALE DISCUSSION 2546 NWS STORM PREDICTION CENTER NORMAN OK 1200 PM CST THU DEC 08 2005 AREAS AFFECTED...OH VALLEY CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION VALID 081800Z - 090000Z A NARROW ZONE OF FREEZING RAIN...WITH RATES RANGING FROM .05-0.1 INCH PER HOUR...IS EXPECTED TO SPREAD NEWD ALONG THE OH RIVER VALLEY INTO SRN OH THIS AFTERNOON. THE HIGHEST RATES SHOULD BE 20-25 MILES EITHER SIDE OF A LINE FROM 30 E OWB TO 20 S LUK TO 30 ESE ZZV. SLEET MAY ALSO MIX IN WITH THE FREEZING RAIN AT TIMES...ESPECIALLY ALONG THE NRN PERIPHERY OF THIS REGION...AS PRECIPITATION TRANSITIONS TO SNOW. THIS MIXED PRECIPITATION SHOULD CHANGE TO MAINLY SNOW BY 21-23Z WEST OF A LINE FROM CMH TO CENTRAL KY. MEANWHILE...ALL SNOW IS EXPECTED NORTH OF THE ZONE OF FREEZING RAIN. SNOWFALL RATES WILL LIKELY INCREASE THROUGH THE AFTERNOON WITH RATES UP TO...AND AT TIMES...EXCEEDING 1 INCH PER HOUR. LARGE SCALE ASCENT WILL CONTINUE TO INCREASE THIS AFTERNOON ACROSS THE OH VALLEY AHEAD OF THE MID LEVEL SHORT WAVE TROUGH WHICH IS MOVING EWD TOWARD WRN IL THIS AFTERNOON. IN RESPONSE TO STRONG HEIGHT FALLS WITH THIS STORM SYSTEM...A SLY LLJ WILL STRENGTHEN TO 60-70 KT ACROSS THE TN VALLEY NOSING INTO NRN KY/SRN OH BY MID-LATE AFTERNOON. THE STRONG UVVS EXPECTED ACROSS IND/NRN KY INTO OH WILL AID IN SATURATING THE INITIALLY DRIER AIR MASS LOCATED BELOW 3 KM AS OBSERVED IN SWRN OH PER 12Z ILN SOUNDING. MOISTURE ADVECTION ALONG THE SLY LLJ WILL AID IN ADDITIONAL MOISTENING OF THE OH VALLEY AIR MASS. WAA ALONG THE NOSE OF THE LLJ IS EXPECTED TO SUPPORT A WARM LAYER BETWEEN 1-2 KM AGL SUFFICIENT FOR A NARROW BAND OF FREEZING RAIN AND AT TIMES MIXED WITH SLEET...GENERALLY ALONG THE IND/KY BORDER INTO FAR SWRN OH AND MUCH OF SOUTH CENTRAL TO SERN OH THIS AFTERNOON. SOUTH OF THIS ZONE OF FREEZING PRECIPITATION...SURFACE TEMPERATURES WILL CONTINUE TO RISE ABOVE 32 F...ALLOWING FOR A TRANSITION TO RAIN. AS THE SURFACE LOW...NOW LOCATED OVER NERN MS/WRN TN...TRACKS INTO ERN KY BY 09/00Z...COOLING IN THE 1-2 KM AGL LAYER GENERALLY WEST OF A LINE FROM CMH TO CENTRAL KY WILL SUPPORT THERMODYNAMIC PROFILES FOR ALL SNOW BY 21-23Z. ..PETERS.. 12/08/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...PBZ...RLX...CLE...JKL...ILN...LMK...IWX...IND...PAH...LOT...ILX... 38048680 38768850 40018833 40758684 41088542 41248441 40838286 40478171 40048124 39108125 38338179 37388335 37188454 37108603 WWWW From MCD at goshenarc.org Thu Dec 8 18:09:19 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 08 Dec 2005 13:09:19 -0500 Subject: [MCD] SWOMCD Message-ID: <200512081807.jB8I7Rbj012103@mail.goshen.edu> ACUS11 KWNS 081806 SWOMCD SPC MCD 081806 VAZ000-NCZ000-WVZ000-SCZ000-TNZ000-GAZ000-090000- MESOSCALE DISCUSSION 2547 NWS STORM PREDICTION CENTER NORMAN OK 1206 PM CST THU DEC 08 2005 AREAS AFFECTED...FAR NWRN SC / WRN NC / WRN VA` CONCERNING...FREEZING RAIN VALID 081806Z - 090000Z THE THREAT OF FREEZING RAIN WITH HOURLY RATES OF LESS THAN 0.05 INCH WILL DEVELOP ACROSS SRN PORTION OF DISCUSSION AREA LATE THIS AFTERNOON INTO EARLY EVENING. PRECIPITATION RATES ARE EXPECTED TO INCREASE TO 0.05-0.15 INCH/HOUR BY MID TO LATE EVENING ACROSS WRN PARTS OF NC/VA. REGIONAL VWPS AND SHORT TERM MODEL GUIDANCE INDICATE THAT PRIMARY BRANCH OF LLJ ASSOCIATED WITH WARM CONVEYOR BELT OF SYNOPTIC SYSTEM OVER THE LOWER MO VALLEY EXTENDED FROM THE CNTRL/ERN GULF COAST INTO THE TN VALLEY AS OF 17Z. WITH NEWD PROGRESSION OF MID-LEVEL LOW PRESSURE INTO THE OH VALLEY LATER THIS AFTERNOON INTO TONIGHT...SSELY LLJ WILL INTENSIFY TO 45-55 KTS ACROSS GA...THE CAROLINAS AND SRN/CNTRL APPALACHIANS. ENHANCED WAA AND ISENTROPIC ASCENT ALONG THIS FEATURE WILL LARGELY DRIVE NWD EXPANSION OF PRECIPITATION SHIELD CURRENTLY IN PLACE ACROSS CNTRL/SRN GA INTO SRN SC. BASED ON 12Z OBSERVED SOUNDINGS...CONSIDERABLE LOW-LEVEL MOISTENING WILL NEED TO OCCUR ACROSS DISCUSSION AREA PRIOR TO THE ONSET OF PRECIPITATION. HOWEVER BY 09/00Z...RUC/NAM FORECAST SOUNDINGS INDICATE SATURATION THROUGH THE LOWEST 3 KM AGL WITH A PRONOUNCED WARM NOSE DEVELOPING IN THE 1-2 KM LAYER. BASED ON CURRENT SURFACE OBSERVATIONS AND MODEL GUIDANCE...IT APPEARS THAT FREEZING RAIN WILL INITIALLY DEVELOP IN THE VALLEYS AND IMMEDIATE LEE OF THE GREAT SMOKEY MOUNTAINS AND BLUE RIDGE WHERE SURFACE COLD WEDGE IS EXPECTED TO PERSIST. FREEZING RAIN...PERHAPS MIXED WITH SLEET...WILL THEN DEVELOP NWD INTO PORTIONS OF WRN VA BETWEEN 09/00 AND 09/03Z. ..MEAD.. 12/08/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...RNK...RLX...GSP...MRX... 35488335 36948188 37388130 37138028 35958062 34908191 34668271 34798354 WWWW From MCD at goshenarc.org Fri Dec 9 00:56:53 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 08 Dec 2005 19:56:53 -0500 Subject: [MCD] SWOMCD Message-ID: <200512090054.jB90sw6T004800@mail.goshen.edu> ACUS11 KWNS 090054 SWOMCD SPC MCD 090054 PAZ000-MDZ000-WVZ000-VAZ000-OHZ000-MIZ000-INZ000-090700- MESOSCALE DISCUSSION 2548 NWS STORM PREDICTION CENTER NORMAN OK 0654 PM CST THU DEC 08 2005 AREAS AFFECTED...SRN MI / IN / OH / WRN PA / NRN WV / WRN MD / NWRN VA CONCERNING...HEAVY SNOW AND SLEET VALID 090054Z - 090700Z LARGE SHIELD OF PRECIPITATION CONTINUES TO MOVE NEWD ACROSS THE OH VALLEY. 1-2 IN/HR SNOWFALL RATES HAVE BEEN REPORTED...WITH HRLY LIQUID EQUIVALENTS BETWEEN 0.05-0.15 INCHES. GIVEN DEEPENING OF SURFACE LOW AS IT MOVES NEWD...AND CONTINUED STRONG MOISTURE ADVECTION OFF THE SURFACE...EXPECT HEAVY SNOW RATES TO BE MAINTAINED AS LARGE SCALE LIFT SHIFTS NEWD INTO WRN PA BY LATE EVENING. IT IS QUITE APPARENT FROM RADAR TRENDS AND MULTIPLE MODELS THAT HEAVIEST SNOW RATES WILL EXIST OVER SERN OH INTO SWRN PA. FARTHER S INTO ERN WV...NWRN VA...AND WRN MD...A MIXTURE OF SLEET AND SNOW IS EXPECTED DUE TO STRONG WARMING ALOFT. 00Z GSO SOUNDING SHOWS WARMING TEMPERATURES NOW ABOVE FREEZING BETWEEN 750-800 MB...AND THIS WILL ADVECT NEWD INTO ERN WV AND WRN MD WHERE PRECIPITATION SHOULD START OFF AS SNOW BUT WILL LIKELY CHANGE TO SLEET BY 06Z. ..JEWELL.. 12/09/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...CTP...LWX...RNK...PBZ...RLX...CLE...ILN...DTX...IWX...GRR...IND... 38068008 38048063 38368080 38518090 38968086 38948115 38968171 38978214 38968261 38798329 39088431 39688620 40378688 41488666 42228668 42448606 42348342 41968267 41438227 41377883 40977816 39767802 39147829 38247895 WWWW From MCD at goshenarc.org Fri Dec 9 00:59:38 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 08 Dec 2005 19:59:38 -0500 Subject: [MCD] SWOMCD Message-ID: <200512090057.jB90vhQf005960@mail.goshen.edu> ACUS11 KWNS 090057 SWOMCD SPC MCD 090056 VAZ000-NCZ000-WVZ000-TNZ000-090700- MESOSCALE DISCUSSION 2549 NWS STORM PREDICTION CENTER NORMAN OK 0656 PM CST THU DEC 08 2005 AREAS AFFECTED...SERN WV/CENTRAL AND SWRN VA/WRN NC CONCERNING...FREEZING RAIN VALID 090056Z - 090700Z FREEZING RAIN IS FORECAST TO OVERSPREAD THIS AREA OVER THE NEXT SEVERAL HOURS...WITH LOCAL RAINFALL RATES OF .05 TO .10"/HR. SOME SIGNIFICANT ICE ACCUMULATION IS EXPECTED. UPPER LOW CONTINUES MOVING ENEWD ACROSS THE MIDWEST/OH VALLEY...WITH A LARGE SSW-NNE BAND OF PRECIPITATION OCCURRING FROM AL NNEWD INTO THE MIDDLE OH VALLEY WITHIN WARM ADVECTION ZONE AHEAD OF UPPER LOW. STRONGEST WARM ADVECTION IS FORECAST TO SHIFT ACROSS THE APPALACHIANS AND INTO THE ATLANTIC COAST STATES THROUGH THIS EVENING...WITH SHARP AXIS OF QG FORCING DEPICTED ALONG AND JUST E OF THE APPALACHIAN CREST BY 09/06Z. WITH 1036 MB SURFACE HIGH ANALYZED ATTM ALONG THE MID-ATLANTIC COAST...STRONG WEDGE/DAMMING EVIDENT ATTM IN LEE OF THE MOUNTAINS WILL PERSIST THROUGH THE EVENING BENEATH STRONG SLY LOW-LEVEL JET /60 TO 70 KT/. THOUGH SURFACE WET-BULB TEMPERATURE ACROSS CENTRAL AND ERN NC WOULD SUGGEST MAINLY RAIN...ZONE OF BELOW FREEZING SURFACE TEMPERATURES SHOULD PERSIST WITHIN THE DISCUSSION AREA OVER CENTRAL AND SWRN VA INTO SERN WV AND SWD ACROSS WRN NC...THUS SUPPORTING FREEZING RAIN. NRN EXTENT OF FREEZING RAIN THREAT APPEARS LIKELY TO SET UP ACROSS CENTRAL VA...WHERE A TRANSITION TO SLEET SHOULD OCCUR. ..GOSS.. 12/09/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...AKQ...LWX...RAH...RNK...RLX...GSP...MRX... 37738111 38277977 38287860 37887769 37237814 36407922 36018074 35368254 35538297 36668161 WWWW From MCD at goshenarc.org Fri Dec 9 05:57:23 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Fri, 09 Dec 2005 00:57:23 -0500 Subject: [MCD] SWOMCD Message-ID: <200512090555.jB95tToq019600@mail.goshen.edu> ACUS11 KWNS 090554 SWOMCD SPC MCD 090554 NYZ000-CTZ000-NJZ000-PAZ000-DEZ000-MDZ000-VAZ000-DCZ000-WVZ000-NCZ000-091200- MESOSCALE DISCUSSION 2550 NWS STORM PREDICTION CENTER NORMAN OK 1154 PM CST THU DEC 08 2005 AREAS AFFECTED...SRN NY..WRN/CENTRAL PA...MD...WV AND VA AND NRN NC CONCERNING...WINTER MIXED PRECIPITATION VALID 090554Z - 091200Z SIGNIFICANT WINTER STORM WILL MOVE INTO THE MID ATLANTIC REGION OVERNIGHT. THREAT FOR HEAVY SNOW WILL DEVELOP NEWD ACROSS CENTRAL/ERN PA...FAR SRN NY...NJ AND WRN/NRN MD THROUGH 12Z. A MIX OF SLEET AND FREEZING RAIN WILL OCCUR SOUTH OF THIS REGION ACROSS PORTIONS OF NRN NC...MUCH OF CENTRAL/NRN VA...SRN/CENTRAL MD AND DE. SNOWFALL RATES FROM 1-2 IN PER HOUR WILL BE MOST LIKELY OVER ERN/CENTRAL PA AND NRN MD WITH THE GREATEST SLEET/FREEZING RAIN RATES UP TO 0.10 IN/HR IN A CORRIDOR FROM SWRN VA INTO THE DC METRO AREA/ERN MD BETWEEN 08-12Z. LATEST RADAR IMAGERY SHOWS AN EXTENSIVE AREA OF PRECIPITATION AHEAD OF A POWERFUL UPPER SYSTEM OVER THE OHIO VALLEY. STRONG MID LEVEL WARM ADVECTION/ISENTROPIC LIFT WILL CONTINUE TO CONTRIBUTE TO AN EXPANDING AREA OF PRECIPITATION OVER THE CENTRAL APPALACHIANS TOWARDS THE HUDSON RIVER VALLEY BY 12Z. STRONG ASCENT IN A THERMODYNAMIC PROFILE SUPPORTING DENDRITE SNOW GROWTH WILL SUPPORT HEAVY SNOWFALL WITH HRLY SNOWFALL RATES FROM 1-2 IN/HR ACROSS MUCH OF CENTRAL/ERN PA...WRN AND NRN MD INTO NJ/SRN NY THROUGH 12Z. FURTHER SOUTH STRONG LOW LEVEL WARM ADVECTION AHEAD OF A COLD FRONT WAS AIDING IN MODERATE PRECIPITATION ACROSS THE SRN APPALACHIANS...THAT WILL CONTINUE TO LIFT NEWD INTO THE MID-ATLANTIC. CURRENT WET BULB FREEZING LINE EXTENDING FROM THE SRN DELMARVA PENINSULA SWD INTO THE PIEDMONT REGION OF NC/SC WILL CONTINUE TO GRADUALLY SHIFT NWD THROUGH THE OVERNIGHT HOURS AS MODERATE PRESSURE FALLS WILL SUPPORT SELY LOW LEVEL FLOW. ELEVATED WARM LAYER WILL BE SUFFICIENTLY DEEP TO CONTINUE TO SUPPORT FREEZING RAIN OVER MUCH OF THE PIEDMONT REGION OF NC THROUGH 09Z...WHILE CONTINUING TO DEVELOP ACROSS MUCH OF SCENTRAL INTO ECENTRAL VA AND SRN MD THROUGH 12Z. NORTH OF THIS REGION...THERE WILL LIKELY CONTINUE TO BE A NARROW CORRIDOR OF ELEVATED WARM NOSE BETWEEN 850-800 MB THAT WILL SUPPORT A MIX OF SLEET WITH THE FREEZING RAIN FROM WCENTRAL/NRN VA INTO THE DC METRO AREA AND MUCH OF DE. ..CROSBIE.. 12/09/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...OKX...ALY...PHI...BGM...AKQ...BUF...CTP...LWX...RAH...RNK...GSP... 40697331 41667354 42107417 42377608 42227785 41337853 39257856 37777955 37138063 36208113 35848040 36797808 37837659 39067461 WWWW From MCD at goshenarc.org Fri Dec 9 06:00:32 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Fri, 09 Dec 2005 01:00:32 -0500 Subject: [MCD] SWOMCD Message-ID: <200512090558.jB95wbWR020652@mail.goshen.edu> ACUS11 KWNS 090557 SWOMCD SPC MCD 090557 COR NYZ000-CTZ000-NJZ000-PAZ000-DEZ000-MDZ000-VAZ000-DCZ000-WVZ000-NCZ000-091200- MESOSCALE DISCUSSION 2550 NWS STORM PREDICTION CENTER NORMAN OK 1157 PM CST THU DEC 08 2005 AREAS AFFECTED...SRN NY..ERN/CENTRAL PA...MD...WV AND VA AND NRN NC CONCERNING...WINTER MIXED PRECIPITATION VALID 090557Z - 091200Z CORRECTED STATE HEADER SIGNIFICANT WINTER STORM WILL MOVE INTO THE MID ATLANTIC REGION OVERNIGHT. THREAT FOR HEAVY SNOW WILL DEVELOP NEWD ACROSS CENTRAL/ERN PA...FAR SRN NY...NJ AND WRN/NRN MD THROUGH 12Z. A MIX OF SLEET AND FREEZING RAIN WILL OCCUR SOUTH OF THIS REGION ACROSS PORTIONS OF NRN NC...MUCH OF CENTRAL/NRN VA...SRN/CENTRAL MD AND DE. SNOWFALL RATES FROM 1-2 IN PER HOUR WILL BE MOST LIKELY OVER ERN/CENTRAL PA AND NRN MD WITH THE GREATEST SLEET/FREEZING RAIN RATES UP TO 0.10 IN/HR IN A CORRIDOR FROM SWRN VA INTO THE DC METRO AREA/ERN MD BETWEEN 08-12Z. LATEST RADAR IMAGERY SHOWS AN EXTENSIVE AREA OF PRECIPITATION AHEAD OF A POWERFUL UPPER SYSTEM OVER THE OHIO VALLEY. STRONG MID LEVEL WARM ADVECTION/ISENTROPIC LIFT WILL CONTINUE TO CONTRIBUTE TO AN EXPANDING AREA OF PRECIPITATION OVER THE CENTRAL APPALACHIANS TOWARDS THE HUDSON RIVER VALLEY BY 12Z. STRONG ASCENT IN A THERMODYNAMIC PROFILE SUPPORTING DENDRITE SNOW GROWTH WILL SUPPORT HEAVY SNOWFALL WITH HRLY SNOWFALL RATES FROM 1-2 IN/HR ACROSS MUCH OF CENTRAL/ERN PA...WRN AND NRN MD INTO NJ/SRN NY THROUGH 12Z. FURTHER SOUTH STRONG LOW LEVEL WARM ADVECTION AHEAD OF A COLD FRONT WAS AIDING IN MODERATE PRECIPITATION ACROSS THE SRN APPALACHIANS...THAT WILL CONTINUE TO LIFT NEWD INTO THE MID-ATLANTIC. CURRENT WET BULB FREEZING LINE EXTENDING FROM THE SRN DELMARVA PENINSULA SWD INTO THE PIEDMONT REGION OF NC/SC WILL CONTINUE TO GRADUALLY SHIFT NWD THROUGH THE OVERNIGHT HOURS AS MODERATE PRESSURE FALLS WILL SUPPORT SELY LOW LEVEL FLOW. ELEVATED WARM LAYER WILL BE SUFFICIENTLY DEEP TO CONTINUE TO SUPPORT FREEZING RAIN OVER MUCH OF THE PIEDMONT REGION OF NC THROUGH 09Z...WHILE CONTINUING TO DEVELOP ACROSS MUCH OF SCENTRAL INTO ECENTRAL VA AND SRN MD THROUGH 12Z. NORTH OF THIS REGION...THERE WILL LIKELY CONTINUE TO BE A NARROW CORRIDOR OF ELEVATED WARM NOSE BETWEEN 850-800 MB THAT WILL SUPPORT A MIX OF SLEET WITH THE FREEZING RAIN FROM WCENTRAL/NRN VA INTO THE DC METRO AREA AND MUCH OF DE. ..CROSBIE.. 12/09/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...OKX...ALY...PHI...BGM...AKQ...BUF...CTP...LWX...RAH...RNK...GSP... 40697331 41667354 42107417 42377608 42227785 41337853 39257856 37777955 37138063 36208113 35848040 36797808 37837659 39067461 WWWW From MCD at goshenarc.org Fri Dec 9 06:15:09 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Fri, 09 Dec 2005 01:15:09 -0500 Subject: [MCD] SWOMCD Message-ID: <200512090613.jB96DExJ025592@mail.goshen.edu> ACUS11 KWNS 090612 SWOMCD SPC MCD 090612 MIZ000-091015- MESOSCALE DISCUSSION 2551 NWS STORM PREDICTION CENTER NORMAN OK 1212 AM CST FRI DEC 09 2005 AREAS AFFECTED...SRN LOWER MI CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION VALID 090612Z - 091015Z HEAVY SNOW WITH HRLY RATES AROUND 1 INCH CENTERED ALONG THE I-96 CORRIDOR WILL GRADUALLY DIMINISH FROM WEST TO EAST THROUGH 10Z. MID LEVEL DEFORMATION ZONE EXTENDING ACROSS SRN LOWER MI WILL CONTINUE TO SHIFT EWD AS UPPER LOW CENTERED OVER NRN IND AT 06Z LIFTS NEWD INTO THE ERN GREAT LAKES THROUGH 12Z. THUS THE HEAVY SNOW BAND SHOULD GRADUALLY END OVER THE GRR AND MUSKEGON AREAS BY 09Z. IN ADDITION...DIMINISHING MID LEVEL MOISTURE TRANSPORT SHOULD SUPPORT A GRADUAL WEAKENING OF THE ERN PORTIONS OF DEFORMATION SNOW BAND LATER TONIGHT. HOWEVER...1 INCH/HR SNOWFALL RATES WILL BE LIKELY THROUGH 10Z ACROSS THE NRN DETROIT METRO AND FLINT AREAS. ..CROSBIE.. 12/09/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...DTX...GRR... 43198262 43188493 43048620 42648633 42318628 42238308 42748249 WWWW From MCD at goshenarc.org Fri Dec 9 13:02:15 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Fri, 09 Dec 2005 08:02:15 -0500 Subject: [MCD] SWOMCD Message-ID: <200512091300.jB9D0OxU018464@mail.goshen.edu> ACUS11 KWNS 091258 SWOMCD SPC MCD 091258 MEZ000-MAZ000-NHZ000-RIZ000-CTZ000-NYZ000-091730- MESOSCALE DISCUSSION 2552 NWS STORM PREDICTION CENTER NORMAN OK 0658 AM CST FRI DEC 09 2005 AREAS AFFECTED...PORTIONS CT...CENTRAL/ERN MA...RI...SRN/ERN NH...SRN MAINE CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION VALID 091258Z - 091730Z HEAVY SNOW IS EXPECTED TO SHIFT/SPREAD EWD ACROSS CENTRAL/ERN NEW ENGLAND THROUGH THE FORENOON HOURS. RATES 1-2 INCHES/HOUR SHOULD BE COMMON...WITH LOCAL 2-3 INCH/HOUR CONVECTIVE SNOW BURSTS EMBEDDED IN PRIMARY PRECIP PLUME. SFC MESOANALYSIS SHOWS COASTAL/MARINE FRONT FROM W-CENTRAL LONG ISLAND ENEWD TO VICINITY HYA AND NEWD INTO BAY OF FUNDY...WITHIN LESS THAN 10 NM S OF FREEZING LINE. EXPECT FRONT TO DRIFT SLOWLY NWD ACROSS COASTAL SERN MA AND CAPE COD AREAS. WAA ATOP SHALLOW FRONTAL LAYER JUST N OF SFC FRONT MAY MELT PRECIP SUFFICIENTLY TO YIELD NARROW/BRIEF CORRIDOR OF FREEZING RAIN FROM RI EWD ACROSS PYM AREA AND PORTIONS CAPE COD...WITH RATES REACHING TO NEAR .10 INCH/HOUR...BEFORE TRANSITIONING TO RAIN. INITIAL LIGHT-MODERATE SNOW...CHANGING TO HEAVY SNOW THEN MIX OF SNOW AND RAIN...IS EXPECTED IN IMMEDIATE FRONTAL ZONE OVER CENTRAL/ERN MAINE COAST AND ADJACENT ISLANDS. AMBIENT PRECIP SHIELD -- MOST INTENSE AT 12Z FROM SRN VT SWWD ACROSS NYC AREA TO DELMARVA REGION -- IS ASSOCIATED WITH INTENSE LOW LEVEL WAA AND MOISTURE TRANSPORT REGIME ELEVATED ATOP VERY COLD/STABLE BOUNDARY LAYER. THIS PRECIP PLUME WILL CONTINUE TO CONTAIN CONVECTIVE ELEMENTS AS IT SHIFTS ENEWD OVER MORE OF CENTRAL/ERN NEW ENGLAND...WITH HEAVY SNOW POSSIBLE AS FAR N AS N-CENTRAL NH...W-CENTRAL AND E-CENTRAL MAINE...AND LIKELY FROM ERN MA ACROSS SRN NH AND INLAND DOWN-EAST MAINE. MODIFIED RUC SOUNDINGS INDICATE EVAPORATIVE/SUBLIMATIVE COOLING OF INITIALLY DRY LOW-MIDLEVEL PROFILE WILL OFFSET WAA ENOUGH TO KEEP DEEP-LAYER THERMODYNAMIC PROFILES COLD ENOUGH TO GENERATE SNOW. MOISTURE TRANSPORT ASSOCIATED WITH 40-50 KT ELEVATED/SLY LLJ WILL HELP TO MAINTAIN PRECIP EFFICIENCY. ..EDWARDS.. 12/09/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...CAR...GYX...BOX...OKX...ALY... 41217350 43077219 44537095 45106980 45676771 45606758 45616747 45536741 45456750 45406742 45226743 45146733 45186716 44856691 44576740 43996840 43556992 42877062 42337093 41887052 41777026 41817012 41947009 42057023 42107020 42077001 41876986 41646989 41607011 41397094 40977350 WWWW From MCD at goshenarc.org Wed Dec 14 00:38:17 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Tue, 13 Dec 2005 19:38:17 -0500 Subject: [MCD] SWOMCD Message-ID: <200512140036.jBE0aQ8f030611@mail.goshen.edu> ACUS11 KWNS 140035 SWOMCD SPC MCD 140035 IAZ000-MNZ000-140430- MESOSCALE DISCUSSION 2553 NWS STORM PREDICTION CENTER NORMAN OK 0635 PM CST TUE DEC 13 2005 AREAS AFFECTED...SCNTRL MN...NCNTRL IA CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION VALID 140035Z - 140430Z A BRIEF PERIOD OF LIGHT FREEZING RAIN COULD OVERSPREAD PORTIONS OF NCNTRL IA AND SCNTRL MN OVER THE NEXT FEW HOURS. LIGHT GLAZE AMOUNTS MAY CAUSE HAZARDOUS DRIVING CONDITIONS BEFORE A CHANGEOVER TO LIGHT SNOW. A SWATH OF PRIMARILY LIGHT RAIN WAS DEVELOPING ENEWD ACROSS THE MO RIVER VALLEY THIS EVENING. THIS PRECIPITATION WAS OCCURRING WITHIN STRONG WARM CONVEYOR BELT...AND BENEATH PRONOUNCED DPVA... ASSOCIATED WITH A SHORT WAVE DISTURBANCE MOVING ACROSS THE PLAINS. SUB-FREEZING SURFACE-BASED AIR MASS BLANKETS ALL OF NERN IA AND SERN MN...WITH THE 32F ISOTHERM ROUGHLY RUNNING SOUTH TO NORTH ACROSS NCNTRL IA TO SCNTRL MN ATTM. A NARROW AXIS OF WARMER AND DRIER AIR ALOFT WAS OVERSPREADING PARTS OF IA AND SRN MN...JUST AHEAD OF THE DEVELOPING PRECIPITATION...BASED ON LATEST SHORT-TERM GUIDANCE AND 00Z RAOBS. NEAR FREEZING WET-BULB TEMPERATURES WITHIN THE ELEVATED DRY LAYER WILL LIKELY RESULT IN A TRANSITION TO ISOTHERMAL PROFILES COLD ENOUGH TO SUPPORT LIGHT SNOW AS PRECIPITATION PERSISTS ACROSS THE REGION LATER TONIGHT. HOWEVER...WITH THE ONSET OF EVAPORATIVE COOLING IN THIS WARM LAYER...THERE MAY BE ENOUGH POSITIVE AREA ALOFT TO SUPPORT A BRIEF PERIOD OF LIGHT FREEZING RAIN. HOURLY PRECIPITATION AMOUNTS OF 0.01-0.05 INCHES HAVE BEEN OCCURRING UPSTREAM. THESE LIGHT AMOUNTS FALLING AS FREEZING RAIN COULD MAKE ROADWAYS HAZARDOUS BEFORE PRECIPITATION CHANGES OVER TO LIGHT SNOW. ..CARBIN.. 12/14/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MPX...DMX...FSD... 42459400 43049459 43759487 44229483 44319429 43949361 43459327 42909311 42509306 42219309 42149351 WWWW From MCD at goshenarc.org Wed Dec 14 05:06:26 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 14 Dec 2005 00:06:26 -0500 Subject: [MCD] SWOMCD Message-ID: <200512140504.jBE54ZWJ029306@mail.goshen.edu> ACUS11 KWNS 140503 SWOMCD SPC MCD 140503 MNZ000-IAZ000-141000- MESOSCALE DISCUSSION 2554 NWS STORM PREDICTION CENTER NORMAN OK 1103 PM CST TUE DEC 13 2005 AREAS AFFECTED...NCNTRL IA...SCNTRL MN CONCERNING...HEAVY SNOW VALID 140503Z - 141000Z SNOWFALL RATES MAY APPROACH 1 INCH PER HOUR IN NORTH CENTRAL IOWA AND SOUTH CENTRAL MINNESOTA FROM 06Z/14 - 10Z/14. SURFACE OBSERVATIONS OVER THE PAST FEW HOURS HAVE INDICATED A TREND TOWARDS MODERATE SNOWFALL IN NORTH CENTRAL IOWA. A STRONG SHORTWAVE TROUGH LOCATED OVER EASTERN KANSAS AND EASTERN NEBRASKA IS PROVIDING AN AREA OF STRONG UPWARD VERTICAL MOTION OVER PORTIONS OF NORTH CENTRAL IOWA AND SOUTH CENTRAL MINNESOTA. 00Z NAM AND 00Z RUC BOTH AGREE THAT THIS AREA OF STRONG LIFT WILL STRENGTHEN FOR THE NEXT SEVERAL HOURS OVER THE REGION...AND GIVEN THE ABUNDANCE OF LOW-LEVEL MOISTURE...SOME AREAS MAY SEE SNOWFALL RATES INCREASE TO AT OR NEAR 1 INCH PER HOUR DURING THE TIME WHEN THE VERTICAL MOTION IS STRONGEST. THE AXIS OF GREATEST LIFT...AND HENCE HEAVY SNOW...WILL PIVOT TOWARDS THE NORTHEAST THROUGH THE NEXT SEVERAL HOURS BEFORE WEAKENING BY 12Z/14. ..LEVIT.. 12/14/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...DVN...ARX...MPX...DMX...FSD... 44899461 43949517 42899497 42089354 42299213 43709212 44789310 WWWW From MCD at goshenarc.org Wed Dec 14 12:44:37 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 14 Dec 2005 07:44:37 -0500 Subject: [MCD] SWOMCD Message-ID: <200512141242.jBECgo48000396@mail.goshen.edu> ACUS11 KWNS 141241 SWOMCD SPC MCD 141241 INZ000-KYZ000-MIZ000-ILZ000-WIZ000-141645- MESOSCALE DISCUSSION 2555 NWS STORM PREDICTION CENTER NORMAN OK 0641 AM CST WED DEC 14 2005 AREAS AFFECTED...PORTIONS ERN/NRN IL...SERN WI...SRN LM...SWRN LOWER MI...MOST OF INDIANA...SMALL PORTION N-CENTRAL KY. CONCERNING...HEAVY SNOW VALID 141241Z - 141645Z WITHIN BROAD NNW-SSE PLUME OF LIGHT-MDT SNOW...POCKETS OF HEAVIER RATES OF 1-1.5 INCHES/HOUR ARE EXPECTED THROUGH MID-LATE MORNING...AS BAND SHIFTS EWD ACROSS DISCUSSION AREA. SNOW SHOULD TRANSITION QUICKLY TO RAIN AT...OR SHORTLY AFTER...PASSAGE OF SFC FREEZING LINE...ALSO FROM SW-NE. MOISTURE CHANNEL IMAGERY AND VWP/PROFILER DATA AT 12Z INDICATED SHORTWAVE TROUGH FROM MSP AREA SEWD ACROSS SWRN IL. EXPECT THIS FEATURE TO DEAMPLIFY GRADUALLY AND EJECT ENEWD ACROSS WI/IL THROUGH REMAINDER MORNING...SUPPORTING PRECURSORY CORRIDOR OF MIDLEVEL DPVA AND STRONG/ELEVATED WAA PLUME IN LOW LEVELS. RELATED ASCENT OF DEEPLY SATURATED AND SUBFREEZING AIR MASS...WITH PW AROUND .5-.75 INCH BASED ON 12Z RAOBS AND INTERMEDIARY RUC SOUNDINGS...SHOULD SUPPORT EWD EXTENSION OF INTERMITTENT HEAVY SNOW NOW OBSERVED IN THIS REGIME. STRONGER DYNAMIC FORCING FARTHER N ACROSS NRN WI AND NWRN LOWER MI SHOULD BE OFFSET BY WEAKER MOISTURE TO LIMIT HEAVY SNOW THREAT...WHILE WARMING WITH TIME WILL RESTRICT SNOW POTENTIAL FARTHER S IN KY. OBSERVATIONAL DATA INDICATES QUICK TRANSITION FROM SNOW TO RAIN W OF SFC FREEZING LINE...A TREND EXPECTED TO CONTINUE THROUGH REMAINDER MORNING. HOWEVER...TIME SERIES OF RUC FCST SOUNDINGS SUGGESTS VERY BRIEF/LOCALIZED EPISODE OF FREEZING RAIN IS POSSIBLE INVOF 32 F ISOTHERM...AS WARMING ALOFT IN DENDRITIC CRYSTAL GROWTH LAYERS KEEPS PRECIP PARTICLES SUPERCOOLED. ANY FREEZING RAIN SHOULD BE SHORT-LIVED WITH RATES GENERALLY AROUND .10 INCH/HOUR OR LESS...AND REPLACED BY RAIN AT ANY GIVEN LOCATION WITHIN AN HOUR OR LESS. ..EDWARDS.. 12/14/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...ILN...LMK...IWX...GRR...IND...PAH...LOT...ILX...MKX... 38568734 39648867 41598911 42968777 42908661 41998603 39028519 37838594 WWWW From MCD at goshenarc.org Wed Dec 14 15:44:59 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 14 Dec 2005 10:44:59 -0500 Subject: [MCD] SWOMCD Message-ID: <200512141543.jBEFhA1C008077@mail.goshen.edu> ACUS11 KWNS 141542 SWOMCD SPC MCD 141542 LAZ000-TXZ000-141745- MESOSCALE DISCUSSION 2556 NWS STORM PREDICTION CENTER NORMAN OK 0942 AM CST WED DEC 14 2005 AREAS AFFECTED...SE TX...SW LA CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 141542Z - 141745Z CONVECTION WILL CONTINUE TO INCREASE ALONG THE UPPER TX COAST OVER THE NEXT FEW HOURS. A FEW OF THE STRONGER CELLS COULD PRODUCE MARGINALLY SEVERE HAIL. IF A SEVERE THREAT DEVELOPS...A WW MAY BECOME NECESSARY LATER THIS MORNING. AT THE SFC...A LOW-LEVEL MOISTURE AXIS EXTENDS NWD FROM JUST OFF THE LOWER TX COAST INTO THE VICTORIA AREA. NUMEROUS THUNDERSTORMS ARE CURRENTLY INCREASING IN INTENSITY ABOVE A WEAKLY CAPPED BOUNDARY LAYER EVIDENT ON THE 12Z SOUNDINGS SUGGESTING THE CONVECTION IS SLIGHTLY ELEVATED. AS AN UPPER-LEVEL TROUGH OVER WEST TX AND THE ASSOCIATED LIFT AHEAD OF THE TROUGH APPROACHES THE REGION LATE THIS MORNING...THE CAPPING INVERSION SHOULD CONTINUE TO WEAKEN ALLOWING CONVECTION TO EXPAND IN COVERAGE AND POSSIBLY ROOT NEARER THE SURFACE ACROSS SE TX INTO FAR SWRN LA. INITIAL ACTIVITY MAY PRODUCE MARGINALLY SEVERE HAIL. HOWEVER...AS THE STORMS BECOME ROOTED IN THE BOUNDARY LAYER...ISOLATED SEVERE THREAT WOULD INCREASE WITH DAMAGING WINDS/ISOLATED TORNADOES POSSIBLE IN THE STRONGER CELLS. ..BROYLES.. 12/14/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LCH...HGX...CRP...EWX... 27549622 27919727 28979756 30259586 30669367 30359193 29549137 28929212 28609344 28309458 WWWW From MCD at goshenarc.org Wed Dec 14 17:53:25 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 14 Dec 2005 12:53:25 -0500 Subject: [MCD] SWOMCD Message-ID: <200512141751.jBEHpaAT028711@mail.goshen.edu> ACUS11 KWNS 141750 SWOMCD SPC MCD 141750 LAZ000-MSZ000-TXZ000-141915- MESOSCALE DISCUSSION 2557 NWS STORM PREDICTION CENTER NORMAN OK 1150 AM CST WED DEC 14 2005 AREAS AFFECTED...FAR SE TX...SRN LA CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 141750Z - 141915Z CONVECTION CURRENTLY OVER SE TX WILL GRADUALLY SPREAD EWD INTO SRN LA OVER THE NEXT HOUR. THE STRONGER STORMS WILL HAVE THE POTENTIAL FOR BRIEF TORNADOES...HAIL AND ISOLATED DAMAGING WIND GUSTS. A WW MAY BE REQUIRED ACROSS THE REGION EARLY THIS AFTERNOON. SFC ANALYSIS CURRENTLY SHOWS ABUNDANT LOW-LEVEL MOISTURE IN PLACE ACROSS SE TX AND SW LA WITH SFC DEWPOINTS ABOVE 60 F EXTENDING EWD FROM THE HOUSTON AREA ACROSS MUCH OF SRN LA. OBJECTIVE ANALYSIS SHOWS A LOW-LEVEL JET AXIS IN PLACE ALONG THE TX COAST EXTENDING NWD INTO WRN LA. THIS FEATURE IS FORECAST BY THE NAM AND GFS SOLUTIONS TO SHIFT EWD THIS AFTERNOON AND INTENSIFY ACROSS SRN AND CNTRL LA. THIS WILL INCREASE LOW-LEVEL MOISTURE ACROSS SRN LA WITH SFC DEWPOINTS GRADUALLY INCREASING THROUGHOUT THE AFTERNOON. INCREASING INSTABILITY AND LARGE-SCALE ASCENT AHEAD OF AN APPROACHING UPPER-LEVEL TROUGH WILL CAUSE STORM COVERAGE TO EXPAND EWD. STRONG VERTICAL SHEAR ESPECIALLY IN THE LOW-LEVELS WILL BE FAVORABLE FOR ISOLATED SUPERCELLS WITH A THREAT FOR TORNADOES. IN ADDITION...HAIL AND A FEW DAMAGING WIND GUSTS WILL BE POSSIBLE WITH THE STRONGER STORMS. ..BROYLES.. 12/14/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...JAN...LIX...LCH...HGX... 30629434 31049369 31229185 31059124 30769096 30239079 29879090 29469124 29249261 29359394 29869441 WWWW From MCD at goshenarc.org Wed Dec 14 19:09:42 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 14 Dec 2005 14:09:42 -0500 Subject: [MCD] SWOMCD Message-ID: <200512141907.jBEJ7vte011672@mail.goshen.edu> ACUS11 KWNS 141905 SWOMCD SPC MCD 141904 LAZ000-TXZ000-142030- MESOSCALE DISCUSSION 2559 NWS STORM PREDICTION CENTER NORMAN OK 0104 PM CST WED DEC 14 2005 AREAS AFFECTED...UPPER TX COAST/FAR SERN TX INTO SWRN LA CONCERNING...TORNADO WATCH 894... VALID 141904Z - 142030Z CONTINUE VALID PORTIONS OF WW AS TORNADO THREAT WILL CONTINUE. BROKEN LINE OF INTENSE THUNDERSTORMS CONTINUES TO EVOLVE JUST WEST OF THE HOU METRO AREA ATTM. THIS ACTIVITY IS TRACKING EWD AT AROUND 35 KT AND SHOULD MOVE ACROSS GALVESTON BAY BY 20Z AND INTO FAR SWRN LA JUST AFTER 21Z IF IT MAINTAINS CURRENT FORWARD MOTION. VWP FROM HOU INDICATES EXTREME LOW LEVEL SHEAR WITH 0-1 KM SRH IN EXCESS OF 350 M2/S2...ALONG WITH 60+ KT OF SFC-6 KM SHEAR. PRIMARY CONCERN CONTINUES TO CENTER AROUND WEAK LOW LEVEL LAPSE RATES AND SUBSEQUENT MAINTENANCE OF SURFACE-BASED STORMS. MODIFIED HOURLY RUC SOUNDINGS INDICATE CONVECTION NEAR AND SOUTH-SOUTHWEST OF HOU IS VERY NEARLY SURFACE-BASED WITH SURFACE TEMPERATURES IN THE LOWER 70S AND DEW POINTS IN THE MID/UPPER 60S. IN ADDITION...STRONG SURFACE PRESSURE FALLS WILL ALSO ENHANCE LIFTING WITHIN THE BOUNDARY LAYER AND FURTHER INCREASE THE RISK OF INGESTING SURFACE-PARCELS. WITH SUCH EXTREME SHEAR...SUPERCELLS WILL CONTINUE TO SUPPORT A RISK OF TORNADOES GIVEN THE NEAR SURFACE-BASED NATURE OF THE STORMS. LARGE HAIL...DAMAGING WINDS AND VERY HEAVY RAINFALL RATES ARE ALSO EXPECTED. SLY LLJ IS FORECAST TO REMAIN ANCHORED INTO THE UPPER TX COAST THROUGH 21Z...SO FURTHER DEVELOPMENT WEST OF ONGOING STORMS MAY OCCUR NEAR THE SURFACE COLD FRONT INTO THE EARLY EVENING. HOWEVER...PRIMARY SEVERE THREAT SHOULD SHIFT INTO SWRN LA BETWEEN 21-00Z AS LLJ DEVELOPS INTO SWRN LA. AS DEW POINTS INCREASE INTO THE MID 60S AND LLJ DEVELOPS EWD...ADDITIONAL WATCH MAY BE NEEDED INTO SWRN LA PRIOR TO 20-21Z. ..EVANS.. 12/14/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LIX...LCH...HGX...CRP...EWX... 28029674 29819661 30879353 30859186 30189144 29439139 29169380 28019671  From MCD at goshenarc.org Wed Dec 14 23:59:16 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 14 Dec 2005 18:59:16 -0500 Subject: [MCD] SWOMCD Message-ID: <200512142357.jBENvR5H007310@mail.goshen.edu> ACUS11 KWNS 142356 SWOMCD SPC MCD 142356 LAZ000-150130- MESOSCALE DISCUSSION 2560 NWS STORM PREDICTION CENTER NORMAN OK 0556 PM CST WED DEC 14 2005 AREAS AFFECTED...SWRN / S-CNTRL LA CONCERNING...TORNADO WATCH 895... VALID 142356Z - 150130Z THROUGH 02Z...POTENTIAL FOR AN ISOLATED TORNADO WILL EXIST ACROSS ERN HALF OF WW AREA...MAINLY ALONG/S OF I-10. REGIONAL RADAR IMAGERY SHOWS THAT ONSHORE PORTION OF QUASI-LINEAR MCS HAS TENDED TO WEAKEN OVER THE PAST HOUR OR TWO WITH MOST INTENSE CONVECTION OBSERVED OFFSHORE SE OF LCH AS OF 2345Z. LATEST MESOANALYSIS INDICATES PRIMARY WARM FRONT FROM VICINITY OF ESF EWD TO S OF JAN...WITH A SECONDARY WARM FRONTAL FEATURE FARTHER TO THE S...EXTENDING FROM WEAK LOW PRESSURE ENE OF LCH SEWD TO N OF HUM. AIR MASS S OF THIS SECONDARY WARM FRONT IS COMPARATIVELY MORE MOIST WITH DEWPOINTS IN THE LOWER 60S...HOWEVER POOR LOW/MID-LEVEL LAPSE RATES ARE LARGELY INHIBITING DESTABILIZATION PROCESS. GIVEN STRONG SHEAR PROFILES OBSERVED ON LOCAL VWPS...THREAT OF AN ISOLATED TORNADO WILL EXIST WITH ANY CONVECTIVE ELEMENTS THAT CAN BECOME SUSTAINED ALONG/S OF THIS SECONDARY WARM FRONT. CURRENTLY...IT APPEARS THAT THE VERY MARGINAL INSTABILITY IS PRIMARY FACTOR LIMITING MORE SUBSTANTIAL ONSHORE DEVELOPMENT. ..MEAD.. 12/14/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LIX...LCH... 29359282 29929284 30519250 30669217 30669144 30079129 29469139 29119153 29119231 WWWW From MCD at goshenarc.org Thu Dec 15 01:14:25 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 14 Dec 2005 20:14:25 -0500 Subject: [MCD] SWOMCD Message-ID: <200512150112.jBF1Ccl0001182@mail.goshen.edu> ACUS11 KWNS 150111 SWOMCD SPC MCD 150111 MIZ000-WIZ000-150445- MESOSCALE DISCUSSION 2562 NWS STORM PREDICTION CENTER NORMAN OK 0711 PM CST WED DEC 14 2005 AREAS AFFECTED...NE WI AND PORTIONS OF UPPER MI CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION VALID 150111Z - 150445Z OCNLY MODERATE SNOW WILL SPREAD NEWD FROM FAR NE WI INTO CNTRL PORTIONS OF UPPER MI THIS EVENING. SNOW RATES WILL GENERALLY REMAIN BELOW 1 IN/HR. EAST OF STACKED UPPER CYCLONE CENTERED ALONG THE WRN MN/ERN DAKOTAS BORDER...LIGHT/OCNLY MDT SNOW FOCUSED EARLY THIS EVENING ACROSS ERN WI INTO MI EAST OF OCCLUDED FRONT. OBSERVATIONAL TRENDS SUGGESTS NEWD SPREAD OF ONGOING SNOWFALL FROM FAR NE WI INTO CNTRL UPPER MI THIS EVENING...ATTRIBUTABLE TO DPVA AND LOW/MID LEVEL ISENTROPIC ASCENT. 00Z GREEN BAY SOUNDING FEATURES 75MB WELL-SATURATED DENDRITIC GROWTH LAYER ABOVE 700MB...FAVORABLE FOR OCNLY MDT SNOW COUPLED WITH AMPLE UVVS. SNOW RATES SHOULD GENERALLY REMAIN BELOW 1 IN/HR...BUT LOCALIZED AREAS COULD EXCEED 1 IN/HR ACROSS THE SCNTRL PORTION OF UPPER MI...INCLUDING MENOMINEE AND DELTA COUNTIES WITH AID OF MOIST SELY TRAJECTORIES OFF LAKE MI. ..GUYER.. 12/15/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...APX...MQT...GRB... 46458604 46118584 45848634 45688661 45218705 44688750 44628799 45188891 45518895 45888884 46328806 WWWW From MCD at goshenarc.org Thu Dec 15 03:07:45 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 14 Dec 2005 22:07:45 -0500 Subject: [MCD] SWOMCD Message-ID: <200512150305.jBF35uRp011039@mail.goshen.edu> ACUS11 KWNS 150305 SWOMCD SPC MCD 150304 ALZ000-MSZ000-LAZ000-150430- MESOSCALE DISCUSSION 2563 NWS STORM PREDICTION CENTER NORMAN OK 0904 PM CST WED DEC 14 2005 AREAS AFFECTED...ERN LA INTO S-CNTRL AND SERN MS CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 150304Z - 150430Z THE THREAT OF ISOLATED DAMAGING WINDS AND PERHAPS A TORNADO APPEARS TO BE INCREASING AND CONVECTIVE TRENDS ARE BEING MONITORED FOR A POSSIBLE WW ISSUANCE. 00Z UPPER-AIR ANALYSIS INDICATES THAT INTENSE FORCING ASSOCIATED WITH A COUPLED UPPER JET STRUCTURE IS LIKELY AIDING IN INTENSIFICATION OF MCS OVER PORTIONS OF S-CNTRL MS INTO ERN LA OVER THE PAST HALF HOUR OR SO. CLOSE INSPECTION OF LOCAL RADAR DATA SHOWS A MESOSCALE CIRCULATION CENTER JUST SE OF MCB MOVING NEWD AT AROUND 50 KTS. ATTENDANT CONVECTIVE LINE FROM S OF JAN TO THIS MESOLOW AND THEN SWD TO N OF HUM HAS ALSO INTENSIFIED PER REFLECTIVITY AND LIGHTNING DATA. 00Z LIX OBSERVED AND PROXIMITY RUC FORECAST SOUNDINGS SUGGEST THAT THIS ACTIVITY IS LIKELY ELEVATED ABOVE A SURFACE STABLE LAYER WITH MUCAPES OF 100-400 J/KG. GIVEN DYNAMIC NATURE OF SYNOPTIC SYSTEM AND NEWD DEVELOPMENT OF PRIMARY SURFACE LOW INLAND ACROSS CNTRL MS OVERNIGHT...SOME CONCERN EXISTS THAT ENOUGH SURFACE-BASED INSTABILITY MAY DEVELOP AHEAD OF ONGOING CONVECTIVE LINE. AMBIENT SHEAR IS QUITE STRONG AND IF STORMS CAN BECOME ROOTED IN THE BOUNDARY-LAYER A THREAT FOR DAMAGING WINDS AND PERHAPS AN ISOLATED TORNADO WOULD INCREASE. ..MEAD.. 12/15/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MOB...JAN...LIX... 30299035 31329061 31749011 32178962 32038888 31408812 30548825 29688903 WWWW From MCD at goshenarc.org Thu Dec 15 03:47:06 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 14 Dec 2005 22:47:06 -0500 Subject: [MCD] SWOMCD Message-ID: <200512150345.jBF3jGFg029879@mail.goshen.edu> ACUS11 KWNS 150344 SWOMCD SPC MCD 150344 VAZ000-NCZ000-WVZ000-SCZ000-TNZ000-GAZ000-150945- MESOSCALE DISCUSSION 2564 NWS STORM PREDICTION CENTER NORMAN OK 0944 PM CST WED DEC 14 2005 AREAS AFFECTED...NRN GA / NWRN SC / WRN NC / WRN VA CONCERNING...FREEZING RAIN VALID 150344Z - 150945Z FREEZING RAIN WITH HOURLY RATES APPROACHING 0.10 TO 0.15 INCH IS EXPECTED TO DEVELOP ACROSS NRN GA/NWRN SC AND SPREAD NEWD ACROSS WRN PORTIONS OF NC AND VA BY 15/12Z. 00Z UPPER-AIR OBSERVATIONS INDICATE THAT FORCING ASSOCIATED WITH A COUPLED UPPER JET STRUCTURE AND LOW-LEVEL WAA ARE THE PRIMARY PROCESSES DRIVING LARGE PRECIPITATION SHIELD CURRENTLY OVER THE LOWER MS VALLEY INTO THE CNTRL GULF STATES AND TN VALLEY. ERN EDGE OF THIS PRECIPITATION SHIELD IS RAPIDLY EXPANDING NEWD ACROSS NRN GA WHERE SURFACE WET BULB TEMPERATURES ARE SUB-FREEZING. 00Z FFC SOUNDING SHOWS THAT LITTLE SATURATION IS NEEDED AROUND 850 MB TO SATURATE VERTICAL PROFILE AND GIVEN CURRENT OBSERVATIONS THIS HAS ALREADY OCCURRED. DEEP-LAYER FORCING FOR ASCENT...PRIMARILY FROM THE TWO AFOREMENTIONED PROCESSES...IS FORECAST TO DEVELOP ENEWD OVERNIGHT...SUSTAINING ONGOING PRECIPITATION SHIELD ACROSS THE CNTRL/SRN APPALACHIANS AND ADJACENT PIEDMONT REGION. STRONG LOW-LEVEL WAA ATOP SURFACE WEDGE FRONTAL ZONE IN IMMEDIATE LEE OF THE APPALACHIANS WILL RESULT IN A QUITE FAVORABLE VERTICAL THERMAL STRATIFICATION FOR FREEZING RAIN WITH A 3-4 C WARM NOSE DEVELOPING AROUND 850 MB. ..MEAD.. 12/15/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LWX...RAH...RNK...CAE...GSP...MRX...FFC... 34368457 35818251 36778111 37558040 38097928 37167871 35897945 34458154 33818322 33588420 WWWW From MCD at goshenarc.org Thu Dec 15 08:34:16 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 15 Dec 2005 03:34:16 -0500 Subject: [MCD] SWOMCD Message-ID: <200512150832.jBF8WSSZ020575@mail.goshen.edu> ACUS11 KWNS 150831 SWOMCD SPC MCD 150831 FLZ000-GAZ000-ALZ000-151030- MESOSCALE DISCUSSION 2565 NWS STORM PREDICTION CENTER NORMAN OK 0231 AM CST THU DEC 15 2005 AREAS AFFECTED...PORTIONS SRN AL...FL PANHANDLE CONCERNING...TORNADO WATCH 896... VALID 150831Z - 151030Z WW MAY BE CLEARED BEHIND PRIMARY SQUALL LINE MOVING EWD OVER WRN-MOST FL PANHANDLE AND ADJACENT MARINE ZONES OF FL/AL BORDER REGION. ALSO...PRIND WW MAY BE REMOVED OVER REMAINING SERN AL COUNTIES. RAIN-COOLED AIR MASS ACROSS SERN AL...WELL N OF MARINE FRONT IN GULF -- WILL NOT RECOVER ENOUGH TO ALLOW NEARLY SFC-BASED LIFTED PARCELS...BEFORE PRIMARY CONVERGENCE BAND PASSES. SFC COLD FRONT IS ANALYZED FROM NRN PORTION MS/AL BORDER SSWWD ACROSS MSY AREA AND INTO NWRN GULF. MAIN CONVECTIVE BAND PRECEDES COLD FRONT BY APPROXIMATELY 125 NM OVER GULF AND NNEWD INTO WRN-MOST FL PANHANDLE. MARINE/WARM FRONT IS ANALYZED NEAR BUOYS 42039 AND 42020...50-70 NM OFFSHORE AND DRIFTING NWD. BOW/LEWP FORMATIONS SHOULD CONTINUE TO DEVELOP ESPECIALLY OVER OFFSHORE WATERS OVER AND S OF MARINE FRONT. TORNADO AND SEVERE WIND POTENTIAL APPEARS TO BE DIMINISHING WITH EWD EXTENT AND WITH TIME BECAUSE OF 1. LOWER THETAE AND WEAKER BUOYANCY IN INFLOW LAYER INLAND AND 2. DECREASING PROBABILITY THAT MARINE FRONT AND ASSOCIATED BOUNDARY LAYER BUOYANCY WILL REACH LAND. INDEED...MODIFIED RUC SOUNDINGS INDICATE SBCAPE AND MLCAPE IS ENTIRELY OFFSHORE NOW. ADDITIONAL CONVECTION MAY DEVELOP ALONG/AHEAD OF SFC COLD FRONT BUT BEHIND INITIAL SQUALL LINE. SEVERE POTENTIAL WITH THIS ACTIVITY SHOULD BE TOO MINIMAL TO MAINTAIN WW BEHIND INITIAL CONVECTION. EXPECT RELATIVELY VEERED FLOW NEAR SFC AND ASSOCIATED REDUCTION OF LOW LEVEL SHEAR...COMBINED WITH REDUCED BUOYANCY IN POSTCONVECTIVE AIR MASS. ..EDWARDS.. 12/15/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...TAE...BMX...MOB... 29878505 29708592 29748733 29918733 31298709 31688534 31318501 30108503 WWWW From MCD at goshenarc.org Thu Dec 15 11:24:57 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 15 Dec 2005 06:24:57 -0500 Subject: [MCD] SWOMCD Message-ID: <200512151123.jBFBNA9A027231@mail.goshen.edu> ACUS11 KWNS 151122 SWOMCD SPC MCD 151122 FLZ000-151315- MESOSCALE DISCUSSION 2566 NWS STORM PREDICTION CENTER NORMAN OK 0522 AM CST THU DEC 15 2005 AREAS AFFECTED...PORTIONS WRN/CENTRAL FL PANHANDLE CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 151122Z - 151315Z NEW WW MAY BE REQUIRED ALONG COASTAL SECTIONS WRN/CENTRAL FL PANHANDLE. ORIGINAL MCS COLLAPSED WHILE MOVING INTO MORE STABLE AIR MASS...EXCEPT FOR SEVERAL CELLS ON ITS SRN END WHICH BROKE AWAY AND REMAIN RELATIVELY DISCRETE AS THEY MOVE NEWD TOWARD WALTON/BAY COUNTY COASTAL WATERS. ADDITIONAL ACTIVITY HAS DEVELOPED S OF AL COAST AND WRN FL PANHANDLE COAST...INVOF COMBINED OUTFLOW BOUNDARY AND MARINE/WARM FRONT...AND ALONG NNE-SSW ORIENTED COLD FRONTAL BAND EXTENDING SEAWARD FROM MOB BAY. SFC ANALYSIS INDICATES MARINE/WARM FRONT NOW ABOUT 40 NM OFFSHORE AL COAST AND WRN FL PANHANDLE...DRIFTING N. FRONT THEN EXTENDS SEWD INVOF BUOY 42036 IN NERN GULF. STRONG LOW LEVEL WAA AND SLY SFC FLOW COMPONENT MAY RESULT IN THIS FRONT -- AND ASSOCIATED NEAR-SFC BASED BUOYANCY -- REACHING COAST DURING NEXT 3-4 HOURS. AIR MASS S OF FRONT WILL BE FAVORABLY UNSTABLE WITH MLCAPES 500-1000 J/KG. VERTICAL SHEAR PROFILES SHOULD BE MAXIMIZED INVOF MARINE FRONT. ALONG THAT BOUNDARY...ELY FLOW COMPONENT -- STRENGTHENED AROUND S RIM OF PRESSURE GRADIENT ASSOCIATED WITH MCS OUTFLOW -- COMBINES WITH 850 MB WINDS THAT VEERED FOLLOWING INITIAL MCS TO YIELD ENLARGED LOW LEVEL HODOGRAPHS. MODIFIED VWP AND RUC SOUNDINGS SHOW 300-600 J/KG SRH IN 0-3 KM LAYER. ACCORDINGLY...SRM DATA INDICATES ROTATION IN SOME CELLS NEAR MARINE FRONT...AND ANY SFC-BASED STORM NEAR COAST WILL BEAR THREAT FOR TORNADOES. DAMAGING GUSTS ALSO MAY REACH SFC IN ANY LEWP/BOW FORMATIONS ASSOCIATED WITH DEVELOPING COLD FRONTAL CONVECTIVE LINE. ..EDWARDS.. 12/15/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...TAE...MOB... 29328472 29468586 29748733 29918733 30608702 30448575 30178487 29948447 WWWW From MCD at goshenarc.org Thu Dec 15 13:41:57 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 15 Dec 2005 08:41:57 -0500 Subject: [MCD] SWOMCD Message-ID: <200512151340.jBFDe9BB017861@mail.goshen.edu> ACUS11 KWNS 151337 SWOMCD SPC MCD 151337 GAZ000-FLZ000-151430- MESOSCALE DISCUSSION 2568 NWS STORM PREDICTION CENTER NORMAN OK 0737 AM CST THU DEC 15 2005 AREAS AFFECTED...PORTIONS FL PANHANDLE AND COASTAL BEND...SWRN GA. CONCERNING...TORNADO WATCH 897... VALID 151337Z - 151430Z SEVERE POTENTIAL REMAINS ALONG/AHEAD OF PRIMARY CONVECTIVE BAND...INDICATED AT 13Z FROM NRN WALTON COUNTY FL SSWWD ACROSS VPS AREA OVER OPEN GULF. SFC MESOANALYSIS INDICATES COMBINED MARINE/WARM FRONT AND OUTFLOW BOUNDARY FROM OLD MCS...NEAR LINE FROM 60 W PIE...15 S AAF...40 S VPS. TSTMS -- INCLUDING A FEW SUPERCELLS...HAVE DEVELOPED ALONG AND S OF THIS FRONT THEN WEAKENED AS THEY EITHER MOVE PROGRESSIVELY FARTHER N OF FRONTAL ZONE OR BECOME ABSORBED BY MAIN CONVECTIVE BAND. THIS TREND SHOULD CONTINUE FOR ANY ADDITIONAL ACTIVITY THAT DEVELOPS IN WARM SECTOR. HOWEVER...AS REGIME SHIFTS EWD TOWARD SEWD-ORIENTED COASTLINE THROUGH 15Z...TORNADO THREAT WILL INCREASE FROM PFN AREA SEWD TO VICINITY AAF WHERE WARM FRONT -- AND ASSOCIATED NEARLY SFC-BASED PARCELS -- IMPINGE ON COASTLINE. THEREAFTER...AIR MASS IS EXPECTED TO DESTABILIZE OVER TLH REGION AND FL COASTAL BEND...AS COMBINATION OF DIURNAL HEATING AND WAA RELATED TO VEERING SFC FLOW ACT TO BOOST SFC THETAE AND INTRODUCE AT LEAST MARGINAL SBCAPES 300-800 J/KG. SBCAPES APCHG 500 J/KG ALREADY ARE EVIDENT N OF WARM FRONT OVER NARROW AREA BETWEEN MAIN CONVECTIVE BAND AND PFN...WHERE 0-1 KM SRH 300-600 J/KG IS EVIDENT BASED ON MODIFIED TLH RAOB...VWP DATA AND RUC SOUNDINGS. ..EDWARDS.. 12/15/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...JAX...TAE... 29378319 29348520 30008652 30468633 30858609 31008484 30998289 30348319 WWWW From MCD at goshenarc.org Thu Dec 15 16:03:54 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 15 Dec 2005 11:03:54 -0500 Subject: [MCD] SWOMCD Message-ID: <200512151602.jBFG29g0000512@mail.goshen.edu> ACUS11 KWNS 151600 SWOMCD SPC MCD 151600 OHZ000-MIZ000-INZ000-152000- MESOSCALE DISCUSSION 2569 NWS STORM PREDICTION CENTER NORMAN OK 1000 AM CST THU DEC 15 2005 AREAS AFFECTED...NE INDIANA/SE MI/NW OH CONCERNING...HEAVY SNOW VALID 151600Z - 152000Z SNOW IS EXPECTED TO INCREASE THROUGH EARLY AFTERNOON FROM FAR NE INDIANA/NW OH INTO SE/THUMB OF MI. SNOW RATES WILL REACH 1 IN/HR ON A LOCALIZED BASIS. EAST OF STACKED LOW CENTERED ALONG THE MN/WI BORDER...OBSERVATIONAL TRENDS FEATURE AXIS OF INCREASING SNOW ACROSS NE INDIANA/WRN OH/FAR SE MI...PART OF BROADER BAROCLINIC LEAF STRUCTURE SEEN IN WATER VAPOR/INFRARED IMAGERY. THIS ACTIVITY IS FOCUSED IN GENERAL SSW-NNE ORIENTATION ALIGNED WITH MID LEVEL FRONTOGENETICAL FORCING BETWEEN 600-700 MB. SIMILAR TO OBSERVATIONAL TRENDS...09Z SREF AND LATEST RUC/WRF GUIDANCE SUGGESTS SNOW SHOULD CONTINUE TO INCREASE FROM FAR NE INDIANA/NW OH INTO SOUTHEAST/THUMB VICINITY OF MI THROUGH EARLY AFTERNOON. ALTHOUGH LOW LEVEL TEMPERATURES PROFILES ARE MARGINAL...AMPLE PRECIPITATION RATES SHOULD BE SUPPORTIVE OF MDT/OCNLY HEAVY WET SNOW. SNOW RATES MAY REACH 1 IN/HR ON A LOCALIZED BASIS INTO MID AFTERNOON. ..GUYER.. 12/15/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...CLE...ILN...DTX...APX...IWX...GRR...IND... 44538346 43738261 41298274 40408345 40298480 40818556 42338507 WWWW From MCD at goshenarc.org Thu Dec 15 17:08:37 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 15 Dec 2005 12:08:37 -0500 Subject: [MCD] SWOMCD Message-ID: <200512151706.jBFH6meg008785@mail.goshen.edu> ACUS11 KWNS 151705 SWOMCD SPC MCD 151705 GAZ000-FLZ000-151800- MESOSCALE DISCUSSION 2570 NWS STORM PREDICTION CENTER NORMAN OK 1105 AM CST THU DEC 15 2005 AREAS AFFECTED...ERN FL PANHANDLE AND FAR SWRN/SRN GA CONCERNING...TORNADO WATCH 897... VALID 151705Z - 151800Z PARAMETERS REMAIN FAVORABLE FOR TORNADOES ACROSS VALID PARTS OF WW 897 FROM THE ERN HALF OF FL PANHANDLE INTO FAR SWRN/SRN GA. GREATEST TORNADO THREAT SHOULD REMAIN ALONG/JUST INLAND OF THE FL COAST. 16Z SURFACE ANALYSIS CONTINUED TO SHOW A MESO-LOW OVER THE CENTRAL FL PANHANDLE AT THE INTERSECTION OF THE COLD FRONT/SQUALL LINE AND A WEDGE FRONT WHICH EXTENDED FROM THIS LOW ACROSS SRN GA TO JUST S OF SAV. A WARM FRONT EXTENDED FROM THE MESO-LOW SEWD JUST N OF AAF AND THEN OFFSHORE OVER THE NERN GULF. HIGHER THETA-E AIR MASS EXISTS S OF THIS WARM FRONT WITH SURFACE DEWPOINTS IN THE MID-UPPER 60S. REGIONAL RADARS INDICATED A BROKEN LINE OF DISCRETE STORMS EXTENDING FROM THE MESO-LOW SWD TO OFFSHORE OVER THE GULF. STRONGER ATTENDANT SHEAR COUPLETS WERE LOCATED WITH ACTIVITY AROUND THE AAF AREA AND SWD OFFSHORE. THESE STORMS WILL CONTINUE TO POSE THE GREATEST RISK FOR TORNADOES AS THIS ACTIVITY INGESTS THE RICHER BOUNDARY LAYER MOISTURE...WHERE 0-3 KM SRH VALUES EXCEED 600 M2/S2. 15Z RUC SUGGESTS THE WARM FRONT SHOULD MOVE INLAND ALONG TAYLOR COUNTY BY 18Z...INCREASING THE POTENTIAL FOR SURFACE BASED STORMS AND ATTENDANT TORNADO/DAMAGING WIND THREAT ACROSS THIS PART OF WW. LATEST TRENDS IN LIGHTNING DATA SUGGEST THE STRONGEST ACTIVITY IS ALONG AND OFFSHORE THE ERN FL PANHANDLE COAST. REGIONAL RADARS ALSO INDICATED A SIMILAR TREND FOR STORMS TO BE WEAKER AND/OR WEAKEN AS THEY MOVE NORTH OF THE WARM FRONT. ..PETERS.. 12/15/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...JAX...TAE... 29558514 31058493 31038262 29668353 29468504 WWWW From MCD at goshenarc.org Thu Dec 15 18:22:43 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 15 Dec 2005 13:22:43 -0500 Subject: [MCD] SWOMCD Message-ID: <200512151820.jBFIKsBm021871@mail.goshen.edu> ACUS11 KWNS 151820 SWOMCD SPC MCD 151819 GAZ000-FLZ000-151915- MESOSCALE DISCUSSION 2571 NWS STORM PREDICTION CENTER NORMAN OK 1219 PM CST THU DEC 15 2005 AREAS AFFECTED...ERN FL PANHANDLE AND FAR SRN GA CONCERNING...TORNADO WATCH 897... VALID 151819Z - 151915Z TORNADO/DAMAGING WIND THREATS EXPECTED TO CONTINUE THROUGH 19-21Z... PRIMARILY ALONG THE COASTAL AREAS OF VALID PART OF WW 897. THUS...ERN PARTS OF WW /TAYLOR...LAFAYETTE AND DIXIE COUNTIES/ MAY NEED TO BE LOCALLY EXTENDED FOR 1-2 HOURS. REGIONAL RADARS/LIGHTNING DATA INDICATED STRONGEST ACTIVITY WAS LOCATED FROM SE OF TLH OVER ERN LEON/WAKULLA COUNTIES AND SWD OFFSHORE OVER THE NERN GULF OF MEXICO. STRONG SHEAR COUPLETS WERE ASSOCIATED WITH OFFSHORE DISCRETE STORMS EXTENDING FROM 50 E AAF TO 60 SSE AAF. AIR MASS DOWNSTREAM OVER THE FL BIG BEND REGION HAS BEEN SLOWLY MODIFYING WITH SURFACE DEWPOINTS INTO THE MID-UPPER 50S. CLOUDINESS ASSOCIATED WITH BROKEN LINE OF STORMS SPREADING DOWNSTREAM ACROSS ERN PARTS OF WW 897 AND THE REST OF NRN FL/SRN GA IS LIMITING OVERALL SURFACE HEATING/DESTABILIZATION. THUS...GIVEN MORE STABLE AIR MASS INLAND OVER NRN FL...NEW WW IS NOT WARRANTED. HOWEVER...SERN PART OF WW MAY NEED TO BE LOCALLY EXTENDED AS STRONGER OFFSHORE STORMS POSE A THREAT TO THESE COUNTIES BETWEEN 19-21Z. ..PETERS.. 12/15/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...TBW...JAX...TAE... 29458482 29918453 31028410 31038258 29378297 29038348 WWWW From MCD at goshenarc.org Thu Dec 15 18:45:52 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 15 Dec 2005 13:45:52 -0500 Subject: [MCD] SWOMCD Message-ID: <200512151844.jBFIi42b004268@mail.goshen.edu> ACUS11 KWNS 151843 SWOMCD SPC MCD 151843 PAZ000-MDZ000-NYZ000-VAZ000-WVZ000-NCZ000-OHZ000-TNZ000-152345- MESOSCALE DISCUSSION 2572 NWS STORM PREDICTION CENTER NORMAN OK 1243 PM CST THU DEC 15 2005 AREAS AFFECTED...MUCH OF PA/FAR SRN NY/WRN AND CNTRL MD/ERN WV/WRN VA/WRN NC CONCERNING...WINTER MIXED PRECIPITATION VALID 151843Z - 152345Z PREDOMINANT FREEZING RAIN/SLEET IS EXPECTED THIS AFTERNOON FROM FAR NE OH INTO WRN/SCNTRL PA AND WRN/CNTRL MD. PRECIPITATION RATES SHOULD INCREASE ACROSS CNTRL/ERN PA THROUGH 21Z-0ZZ...WITH SNOW PREDOMINANT PRECIP TYPE. FURTHER SOUTH...FREEZING RAIN WILL CONTINUE FOR THE NEXT SEVERAL HOURS ALONG THE SPINE OF THE CNTRL APPALACHIANS...WITH A GRADUAL CHANGE OVER TO ALL RAIN OCCURRING FROM SOUTH TO NORTH THIS AFTERNOON. EXTENSIVE PRECIPITATION SHIELD WILL CONTINUE TO SPREAD E/NE FROM THE OHIO VALLEY/MID ATLANTIC INTO THE NE STATES THIS AFTERNOON...ATTRIBUTABLE TO AMPLE UVVS VIA JUXTAPOSITION OF DPVA/UPPER JET ENHANCED LIFT AND LOW LEVEL WAA/MOISTURE TRANSPORT REGIME. IN ACCORDANCE WITH OBSERVATIONAL TRENDS...15Z RUC SOUNDINGS AND 09Z SREF CONSENSUS/WINTER ALGORITHMS SUGGEST RELATIVELY LONGEST DURATION/GREATEST PROBABILITY FOR FREEZING RAIN AND/OR SLEET THROUGH 21Z-00Z SHOULD OCCUR ACROSS WRN/SCNTRL PA...WRN/CNTRL MD...AND ERN WV/NW VA. IN THESE AREAS...ENCROACHING 800-850 MB LEVEL WARM LAYER /AS SAMPLED BY 12Z ROANOKE RAOB/ WILL BE FAVORABLE FOR FREEZING RAIN AND/OR SLEET WHERE SUB-FREEZING NEAR-SFC TEMPS ARE MAINTAINED...WHICH IS ESPECIALLY LIKELY IN VALLEY AREAS. WITH SOUTHWARD EXTENT...OWING TO STRONG WARM AIR ADVECTION REGIME...INITIAL COLD WEDGE WILL GRADUALLY BE OVERCOME ALONG/EAST OF THE CNTRL APPALACHIANS THROUGH THE AFTERNOON. PREDOMINANT PRECIP-TYPE IS EXPECTED TO GRADUALLY CHANGE FROM FREEZING RAIN TO RAIN ACCORDINGLY FROM SOUTH TO NORTH ACROSS THE NW NC/VA APPALACHIANS. ..GUYER.. 12/15/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...PHI...BGM...BUF...CTP...LWX...RNK...PBZ...RLX...CLE...GSP...MRX... 39847594 38947734 36697977 35838135 36068174 36598178 37628113 38897964 40268013 41098099 41888047 42387805 41237558 WWWW From MCD at goshenarc.org Thu Dec 15 19:26:14 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 15 Dec 2005 14:26:14 -0500 Subject: [MCD] SWOMCD Message-ID: <200512151924.jBFJORBP029808@mail.goshen.edu> ACUS11 KWNS 151923 SWOMCD SPC MCD 151923 MIZ000-152300- MESOSCALE DISCUSSION 2573 NWS STORM PREDICTION CENTER NORMAN OK 0123 PM CST THU DEC 15 2005 AREAS AFFECTED...NE LOWER MI CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION VALID 151923Z - 152300Z OCNLY MODERATE SNOW WILL DEVELOP/SPREAD FROM THE THUMB AREA INTO NE LOWER MI THROUGH MID AFTERNOON. RATES COULD REACH 1 IN/HR WITHIN THE HEAVIER BANDS FOR A FEW HOURS DURATION BETWEEN 20Z-00Z. VOLUMETRIC RADAR TRENDS SUGGESTS AREAS OF MODERATE SNOW...ONGOING EARLY THIS AFTERNOON ACROSS SE LOWER MI...SHOULD CONTINUE TO SPREAD N/NE INTO THE NE PORTION OF LOWER MI REMAINDER OF THE AFTERNOON. SIMILAR TO OBSERVATIONAL TRENDS...SHORT-TERM RUC/4KM WRF GUIDANCE SUGGESTS THIS WILL GENERALLY OCCUR IN AREAS ALONG/EAST OF INTERSTATE 75. ATTRIBUTABLE TO AMPLE UVVS/SATURATED FAVORABLE DENDRITIC GROWTH ZONE PER 18Z RUC SOUNDINGS...SNOW RATES COULD LOCALLY REACH 1 IN/HR FOR A COUPLE HOURS DURATION. ..GUYER.. 12/15/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...DTX...APX... 45528411 45258321 44588303 43998290 43488319 43498410 43758437 44668453 WWWW From MCD at goshenarc.org Thu Dec 15 22:49:41 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 15 Dec 2005 17:49:41 -0500 Subject: [MCD] SWOMCD Message-ID: <200512152247.jBFMlvMi017004@mail.goshen.edu> ACUS11 KWNS 152247 SWOMCD SPC MCD 152246 FLZ000-160015- MESOSCALE DISCUSSION 2574 NWS STORM PREDICTION CENTER NORMAN OK 0446 PM CST THU DEC 15 2005 AREAS AFFECTED...WRN FL PENINSULA CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 152246Z - 160015Z POTENTIAL FOR AN ISOLATED TORNADO OR LOCALLY STRONG WINDS WILL EXIST ACROSS DISCUSSION AREA THIS EVENING. OVERALL SEVERE THREAT APPEARS QUITE LIMITED AND A WW IS NOT ANTICIPATED. AS OF 2235Z...TAMPA RADAR INDICATED A PRE-FRONTAL BAND OF TSTMS OFF THE WRN FL PENINSULA WITH THE MOST INTENSE ACTIVITY FROM 45 NW OF PIE TO 60 W PIE. LOCAL AIR MASS ALONG THE COAST IS MOIST AND MODERATELY UNSTABLE WITH MUCAPES OF AROUND 1000 J/KG. ADDITIONALLY...AMBIENT SHEAR PROFILES REMAIN SUPPORTIVE OF ORGANIZED STORMS /SUPERCELLS/ WITH EFFECTIVE BULK SHEARS OF 35-40 KTS AND 0-1 KM SRH OF 200-250 M2/S2. POTENTIAL FOR AN ISOLATED TORNADO OR LOCALLY DAMAGING WIND GUST WILL EXIST WITH THE MOST INTENSE STORMS AS THEY APPROACH THE COAST. HOWEVER...IT APPEARS THAT THE ABSENCE OF ANY APPRECIABLE LARGE-SCALE FORCING AND DEEP FRONTAL CONVERGENCE SHOULD TEND TO LIMIT THE OVERALL SEVERE WEATHER THREAT...ESPECIALLY AS THE BOUNDARY-LAYER COOLS LATER THIS EVENING. ..MEAD.. 12/15/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...TBW...JAX... 29008292 29378266 29388221 28708209 28268225 28048264 28288295 WWWW From MCD at goshenarc.org Fri Dec 16 01:21:24 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 15 Dec 2005 20:21:24 -0500 Subject: [MCD] SWOMCD Message-ID: <200512160119.jBG1Jb6u012833@mail.goshen.edu> ACUS11 KWNS 160118 SWOMCD SPC MCD 160118 CTZ000-MAZ000-NYZ000-NJZ000-PAZ000-MDZ000-VAZ000-WVZ000-160545- MESOSCALE DISCUSSION 2575 NWS STORM PREDICTION CENTER NORMAN OK 0718 PM CST THU DEC 15 2005 AREAS AFFECTED...SRN AND CNTRL NY/MUCH OF PA/WRN CT/NRN NJ/MD/FAR NRN VA/WV PANHANDLE CONCERNING...WINTER MIXED PRECIPITATION VALID 160118Z - 160545Z PRIMARILY FREEZING RAIN...WITH POTENTIAL FOR ICE ACCUMULATIONS...WILL CONTINUE TO TRANSITION NEWD ACROSS CNTRL/ERN PA...NRN NJ...INTO SRN/CNTRL NY AND WRN CT THIS EVENING. ACROSS WRN PA/WRN NY...A CHANGE OVER TO ALL SNOW IS EXPECTED THIS EVENING...WITH MDT/LOCALLY HEAVY SNOW DEVELOPING BY LATE EVENING/OVERNIGHT. FURTHER SOUTH...INITIAL FREEZING RAIN SHOULD CHANGE OVER TO RAIN ACROSS NRN VA/MUCH OF MD/SE PA/MOST OF NJ PRIOR TO 06Z. WITH BROAD NEGATIVE TILT TROUGH CENTERED OVER THE UPPER MISSISSIPPI VALLEY...VORTICITY MAX AND STRONG MID/UPPER JET CONTINUES TO RACE EWD TOWARD THE MID ATLANTIC/NORTHEAST STATES WITHIN BASE OF UPPER TROUGH. ACCORDINGLY...BROAD/DEEP FORCING FOR ASCENT IS CONTRIBUTING TO NEWD TRANSITION OF BROAD PRECIPITATION SHIELD INTO THE NORTHEAST STATES. AS SEEN IN THE 00Z WASHINGTON-DULLES RAOB...NWD EXTRAPOLATION OF ELEVATED MELTING LAYER WILL REMAIN SUPPORTIVE OF FREEZING RAIN AS PRIMARY PRECIP-TYPE ACROSS MUCH OF CNTRL/ERN PA AND NRN NJ INTO SRN/CNTRL NY AND WRN CT MUCH OF THE EVENING...WHERE WEDGE OF SHALLOW COLD AIR WILL BE MAINTAINED. SOME SLEET/SNOW WILL BE POSSIBLE AS WELL. FURTHER WEST...00Z PITTSBURG AND 00Z BUFFALO RAOBS FEATURE A 1-2C WARM LAYER NEAR 850 MB...STILL AT LEAST MARGINALLY SUPPORTIVE OF FREEZING RAIN/SOME SLEET. HOWEVER...WITH NOCTURNAL/DYNAMIC COOLING AND EVENTUAL COLD ADVECTION...21Z RUC GUIDANCE SUGGESTS A GRADUAL CHANGE OVER TO ALL SNOW SHOULD OCCUR ACROSS MUCH OF WRN PA/WRN NY BY LATE EVENING...WITH MDT/LOCALLY HEAVY SNOW PREVALENT INTO THE OVERNIGHT. SNOW RATES MAY REACH 1 IN/HR IN THESE AREAS BY 06Z. ..GUYER.. 12/16/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...BOX...OKX...ALY...PHI...BGM...BUF...CTP...LWX...PBZ...RLX...CLE... 43007437 41607284 41177380 40127503 39637663 39227774 38567885 38737931 39677952 40097994 41568027 43177865 43397632 WWWW From MCD at goshenarc.org Fri Dec 16 06:51:04 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Fri, 16 Dec 2005 01:51:04 -0500 Subject: [MCD] SWOMCD Message-ID: <200512160649.jBG6nK1N028718@mail.goshen.edu> ACUS11 KWNS 160648 SWOMCD SPC MCD 160647 MEZ000-MAZ000-NHZ000-RIZ000-VTZ000-CTZ000-NYZ000-NJZ000-PAZ000-161215- MESOSCALE DISCUSSION 2576 NWS STORM PREDICTION CENTER NORMAN OK 1247 AM CST FRI DEC 16 2005 AREAS AFFECTED...MUCH OF NEW ENGLAND/NRN APPALACHIANS CONCERNING...WINTER MIXED PRECIPITATION VALID 160647Z - 161215Z A MIX OF FREEZING RAIN/SLEET AND SNOW WILL DEVELOP ACROSS MUCH OF NEW ENGLAND OVERNIGHT. FREEZING RAIN WILL CHANGEOVER TO MODERATE TO HEAVY SNOW /HRLY RATES UP TO 1 INCH/ ACROSS PORTIONS OF CENTRAL/NRN PA INTO WRN/NRN NY...WITH FREEZING RAIN CHANGING OVER TO RAIN OVER FAR NRN NJ/NERN PA...THE LOWER HUDSON RIVER VALLEY AND MUCH OF CT THROUGH 12Z. HOURLY FREEING RAIN/SLEET RATES AROUND 0.10 INCH WILL BE COMMON ACROSS PORTIONS OF THE MIDDLE HUDSON RIVER VALLEY OF ECENTRAL NY AND WRN PORTIONS OF MA/FAR SRN VT/SRN NH...LEADING TO THE POTENTIAL FOR SIGNIFICANT SLEET AND ICING IN THESE AREAS THROUGH 12Z. STRONG LOW LEVEL WAA WILL CONTINUE IN ADVANCE OF POTENT UPPER TROUGH MOVING THROUGH THE OHIO VALLEY. AT THE SURFACE...THE TREND OF A SLOWLY LIFTING SURFACE 32 DEG F LINE WILL CONTINUE OVERNIGHT AS A SURFACE LOW PRESSURE CENTERED OVER NEAR BWI AT 05Z LIFTS TOWARDS NYC BY 12Z. THEREFORE...NRN NJ...NERN PA...THE LOWER HUDSON RIVER VALLEY AND MUCH OF CT WILL SEE A CHANGEOVER FROM FREEZING PRECIP TO RAIN THROUGH 12Z. FURTHER NORTH...THE STRENGTH OF THE WAA AND GRADUAL SHRINKING OF THE ELEVATED WARM LAYER DEPTH DUE TO ASCENT WILL SUPPORT A MIX OF MODERATE TO OCCASIONALLY HEAVY FREEZING RAIN AND SLEET ACROSS MUCH OF ECENTRAL/NERN NY...VT/NH AND MA THROUGH 12Z. FURTHER WEST...LOW LEVEL CAA WAS COMMENCING PER VWP DATA AT PBZ. IN ADDITION...MID LEVEL FRONTOGENESIS WILL CONTINUE TO INTENSIFY IN THE 700-600 MB LAYER SUPPORTING DENDRITIC SNOW GROWTH. THESE TWO WILL COMBINE TO AID IN A CHANGEOVER OF P-TYPE FROM FREEZING RAIN TO MOD-HVY SNOW OVER NCENTRAL PA NWD INTO WRN/NRN NY...ESPECIALLY DURING THE 08-12Z TIME FRAME. ..CROSBIE.. 12/16/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...GYX...BOX...BTV...OKX...ALY...PHI...BGM...BUF...CTP...PBZ... 44387148 43317068 42237116 41737201 41157332 41117459 41077533 40937637 40587783 41147903 43077776 44837533 44907298 WWWW From MCD at goshenarc.org Fri Dec 16 11:57:35 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Fri, 16 Dec 2005 06:57:35 -0500 Subject: [MCD] SWOMCD Message-ID: <200512161155.jBGBtoe6014561@mail.goshen.edu> ACUS11 KWNS 161155 SWOMCD SPC MCD 161154 MEZ000-MAZ000-NHZ000-VTZ000-NYZ000-161700- MESOSCALE DISCUSSION 2577 NWS STORM PREDICTION CENTER NORMAN OK 0554 AM CST FRI DEC 16 2005 AREAS AFFECTED...NERN NY...VT...NH...ME...NWRN MA CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION VALID 161154Z - 161700Z ...WINTER STORM PRODUCING AREAS OF ICE AND SNOW ACROSS THE NORTHEAST... FZRA WILL CREATE HAZARDOUS ICING FROM PARTS OF ERN NY... MA...SRN VT/NH...AND SWRN ME THIS MORNING. MDT TO HVY SN WILL FALL FROM CNTRL/NERN NY...AND ALONG THE CANADIAN BORDER FROM VT/NH TO INTERIOR MAINE. A BROAD TRANSITION ZONE OF SN...PL...AND FZRA WILL CONTINUE FROM CNTRL VT/NH TO MAINE THIS MORNING BEFORE CHANGING BACK TO SN BY AFTERNOON. AN INTENSE AND FAST-MOVING MID/UPPER LEVEL IMPULSE WAS ROTATING THROUGH THE ERN PERIPHERY OF A LARGE CLOSED LOW OVER WI THIS MORNING. DPVA ASSOCIATED WITH THE IMPULSE/JET HAS INDUCED SURFACE CYCLOGENESIS ALONG COASTAL BAROCLINIC ZONE VICINITY OF NJ. VERY TIGHT PRESSURE GRADIENT BETWEEN THE DEEPENING SECONDARY LOW AND A STRONG SURFACE HIGH OVER SRN QUEBEC WAS CONTRIBUTING TO PRONOUNCED INFLUX OF ATLANTIC MOISTURE NWWD AND INLAND ATOP SURFACE-BASED COLD DOME FROM ERN NY ACROSS NRN NEW ENGLAND. MID/UPPER LEVEL DRYING WAS DEVELOPING NEWD ACROSS VT/NH EARLY THIS MORNING BASED ON RECENT SATELLITE AND RADAR TRENDS. THIS WILL RESULT IN LOWER PCPN RATES IN THE SHORT TERM ACROSS THESE AREAS. WRF AND ENSEMBLE MEAN QPF WERE INDICATING ONE PCPN MAX ASSOCIATED WITH LIFT NEAR THE SURFACE LOW/BAROCLINIC ZONE...AND ANOTHER PCPN MAX FROM NERN NY TO SRN QUEBEC. AREAS IN THE SRN ZONE OF HEAVIER PCPN... FROM SERN NY ACROSS MA AND INTO SRN NH AND MAINE...MAY EXPERIENCE A PERIOD OF HVY ICING THIS MORNING AS WARMER AIR ALOFT CONTINUES TO SPREAD INLAND OVER THE SUB-FREEZING AIR AT THE SURFACE. SN WILL CHANGE TO A PERIOD OF FZRA IN THESE AREAS. THIS HAS ALREADY HAPPENED OVER SWRN MA...AND IS EXPECTED TO DEVELOP NEWD ACROSS SRN NH AND ME OVER THE NEXT FEW HOURS. FARTHER NORTH...SECONDARY PCPN MAXIMUM...FROM NERN NY ACROSS SRN QUEBEC...NRN VT/NH...AND INTERIOR ME...WILL LIKELY BE PRIMARILY IN THE FORM OF SN. INTENSE QG FORCING FOR ASCENT WILL CONTINUE TO PIVOT ENEWD FROM CNTRL/NERN NY THIS MORNING...AND ACROSS NRN NEW ENGLAND TO INTERIOR ME THROUGH THIS AFTERNOON. DYNAMIC COOLING IN THE LOW TO MID LEVELS WILL OFFSET WARM ADVECTION AND...COUPLED WITH INFLUX OF MOISTURE INTO THIS REGION...SUPPORT MDT TO HVY SN ON THE NRN EDGE OF THE PCPN TRANSITION ZONE. SN WILL TAPER OFF AND END FROM WEST TO EAST AS THE STRONGER UPPER FORCING MOVES ACROSS THESE AREAS THROUGH THE DAY. ..CARBIN.. 12/16/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...CAR...GYX...BOX...BTV...ALY...BGM...BUF... 46297016 45717074 45447138 45327257 45147396 44837539 44267584 43177599 42847534 42817408 42127365 42057269 42447120 42887082 43477058 44136923 45856858 46386920 WWWW From MCD at goshenarc.org Fri Dec 16 18:48:50 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Fri, 16 Dec 2005 13:48:50 -0500 Subject: [MCD] SWOMCD Message-ID: <200512161847.jBGIl7IR005955@mail.goshen.edu> ACUS11 KWNS 161846 SWOMCD SPC MCD 161845 MEZ000-NHZ000-VTZ000-162245- MESOSCALE DISCUSSION 2578 NWS STORM PREDICTION CENTER NORMAN OK 1245 PM CST FRI DEC 16 2005 AREAS AFFECTED...NRN VT/NH/MUCH OF ME CONCERNING...HEAVY SNOW VALID 161845Z - 162245Z ...SNOW WILL BE INCREASING IN INTENSITY ACROSS MUCH OF ME THIS AFTN...WITH RATES OF 1 TO 2 INCHES PER HOUR. MODERATE TO HEAVY SNOW WILL BE DIMINISHING ACROSS VT/NH WITHIN 1-3 HOURS... LATEST SFC ANALYSIS SHOWS RAPIDLY FALLING SFC PRESSURE /2-3MB PER HOUR OFFSHORE/ WITH LOW NOW NEAR BEDFORD. SYSTEM IS QUICKLY LIFTING NORTHEAST WITH DRIER AIR APPROACHING FROM THE SW PER WV LOOPS. COMPOSITE RADAR IMAGERY DEPICTS ENHANCED REFLECTIVITY RETURNS ACROSS SRN ME NEAR PORTLAND. RECENT SFC OBSERVATIONS AT KDAW /DAWSON/ INDICATED HEAVY RAIN...WITH HEAVY SNOW NOW AT KIZG /FRYEBERG/...AS THIS MORE INTENSE PRECIPITATION MOVES BY. THERMAL PROFILES SUPPORT ALL SNOW...EXCEPT NEAR THE COASTAL AREAS WHERE RAIN WILL OCCUR. SNOW RATES WILL BE ENHANCED BOTH BY STRONG FRONTOGENESIS THROUGH A DEEP LAYER AND A SATURATED DENDRITIC ZONE...WHICH FORECAST SOUNDINGS SUGGEST WILL BE MAINTAINED TIL AT LEAST 21Z AROUND KBGR AND THROUGH 00Z NEAR KCAR. HEAVY SNOW NOW ONGOING ACROSS NRN PORTIONS OF VT/NH WILL END WITHIN A COUPLE HOURS. BUT IT APPEARS MODERATE TO HEAVY SNOW WILL CONTINUE ACROSS MUCH OF ME THROUGH THE AFTN. ..TAYLOR.. 12/16/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...CAR...GYX...BOX...BTV... 46537078 47446915 47086764 46066784 44886871 43067142 43337229 44167251 44997261 WWWW From MCD at goshenarc.org Sun Dec 18 08:17:32 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sun, 18 Dec 2005 03:17:32 -0500 Subject: [MCD] SWOMCD Message-ID: <200512180815.jBI8FqGn015072@mail.goshen.edu> ACUS11 KWNS 180814 SWOMCD SPC MCD 180814 CAZ000-181415- MESOSCALE DISCUSSION 2579 NWS STORM PREDICTION CENTER NORMAN OK 0214 AM CST SUN DEC 18 2005 AREAS AFFECTED...CA SIERRA NEVADA MOUNTAINS CONCERNING...HEAVY SNOW VALID 180814Z - 181415Z HEAVY WET SNOW IS EXPECTED TO OVERSPREAD THE SIERRA RANGE IN THE NEXT SEVERAL HOURS AS MOIST PACIFIC STORM SYSTEM MOVES INLAND. SNOWFALL RATES AOA 6000 FEET COULD EXCEED 2 INCHES PER HOUR THIS MORNING. OVER THE NEXT SEVERAL HOURS...PRECIPITATION RATES WILL CONTINUE TO INCREASE AND SPREAD INLAND FROM THE COAST AND ACROSS THE CNTRL VALLEY OF CA AS POTENT PACIFIC PERTURBATION MOVES EAST ACROSS THE NCNTRL CA COAST. OBSERVED RAINFALL RATES NEAR THE COAST WERE ALREADY IN THE RANGE OF 0.10 TO 0.25 INCHES PER HOUR WITHIN WARM AIR ADVECTION REGIME AHEAD OF THE STRONGER DYNAMIC FORCING. /REF NFDSPENES WMO HEADER TXUS20/. INTENSIFYING UPSLOPE FLOW AND DYNAMIC FORCING WITH THE MID/UPPER LEVEL IMPULSE/WIND MAX...ALONG WITH ENHANCED MOISTURE TRANSPORT ACCOMPANYING +1 INCH PW PLUME...WILL LEAD TO EXCESSIVE SNOWFALL RATES DEVELOPING ACROSS THE HIGHER ELEVATIONS THROUGH 12Z. WHILE SNOW LEVELS MAY INITIALLY CLIMB ABOVE 6000 FEET...FREEZING LEVELS WILL BEGIN TO FALL LATER THIS MORNING AS ADIABATIC COOLING WITHIN THE UPPER TROUGH AXIS SPREADS ACROSS THE AREA. WITH POTENTIAL FOR EMBEDDED CONVECTION...AND DECENT AGREEMENT IN LATEST SHORT-TERM QPF GUIDANCE FROM NAM AND RUC MODELS...SNOWFALL RATES OF 2-4 INCHES PER HOUR APPEAR LIKELY NEAR AND SOUTH OF THE TAHOE AREA BEFORE 12Z. WINDS ALSO INCREASING TO NEAR 50KT LATER THIS MORNING WILL PRODUCE DRIFTING SNOW AND WHITE-OUT CONDITIONS. ..CARBIN.. 12/18/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...VEF...REV...HNX...STO... 37021850 36771865 37371945 37972000 38232022 38682029 39242058 39532070 39762078 40232140 40502156 40502133 40442108 40292076 40112059 39902037 39672017 38932008 37431870 WWWW From MCD at goshenarc.org Sun Dec 18 18:57:33 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sun, 18 Dec 2005 13:57:33 -0500 Subject: [MCD] SWOMCD Message-ID: <200512181855.jBIItsto029089@mail.goshen.edu> ACUS11 KWNS 181855 SWOMCD SPC MCD 181855 NVZ000-IDZ000-ORZ000-CAZ000-190100- MESOSCALE DISCUSSION 2580 NWS STORM PREDICTION CENTER NORMAN OK 1255 PM CST SUN DEC 18 2005 AREAS AFFECTED...CNTRL AND ERN ORE/SIERRA/NRN NV CONCERNING...HEAVY SNOW VALID 181855Z - 190100Z ...MODERATE TO HEAVY SNOW WILL CONTINUE ACROSS THE NRN GREAT BASIN THROUGH AFTN...WITH SNOW SPREADING INTO THE ERN SLOPES OF THE CASCADES WITHIN A FEW HOURS. SNOW RATES ABOVE 4000 FEET MAY BE IN THE 2-3 INCH PER HOUR RANGE... LATEST IR SATELLITE IMAGERY SHOWS INCREASING MOISTURE/CLOUDS MOVING ACROSS SRN ID/ORE WITH SOME COOLING CLOUD TOPS NOTED. ENHANCED BAND OF CLOUDS SEEMS TO BE ASSOCIATED WITH DEFORMATION BAND NEAR 700MB. HEAVIEST SNOW CURRENTLY OVER NRN PORTIONS OF NV FROM LOL/WMC/EKO. MEANWHILE...SNOW HAS CHANGED OVER TO RAIN IN THE TAHOE/RENO AREA...SUGGESTING FROM THE SFC OBSERVATIONS THAT THE FREEZING LEVEL HAS RISEN ABOVE 6000 FEET. BAND OF SNOW IS EXPECTED TO INCREASE FROM DESCHUTES CO ORE INTO SW ID AND NW UT...ASSOCIATED WITH FRONTOGENETIC FORCING WITHIN THE 750-650 MB LAYER AND UPWARD MOTION DUE TO VORTICITY ADVECTION. THIS IS SUPPORTED BY THE ETA/RUC/GFS. SNOW RATES MAY RANGE FROM 1 TO 2 INCHES PER HOUR. SOME FZRA HAS BEEN OBSERVED NORTH OF MEDFORD EARLIER...BUT MOST LOCATIONS HAVE TEMPS ABOVE FREEZING NOW. EXCEPTION MAY BE IN VALLEY LOCATIONS WHERE STRONG INVERSION IS HOLDING DOWN TEMPS. HEAVY SNOW WILL ALSO CONTINUE IN THE HIGHER ELEVATIONS OF THE SIERRA ..TAYLOR.. 12/18/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...BOI...LKN...PDT...REV...MFR...PQR... 39391884 40252000 41862008 42232251 43122257 45402189 45511851 44741731 42231521 40151489 WWWW From MCD at goshenarc.org Mon Dec 19 01:00:29 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sun, 18 Dec 2005 20:00:29 -0500 Subject: [MCD] SWOMCD Message-ID: <200512190058.jBJ0wqwi010452@mail.goshen.edu> ACUS11 KWNS 190058 SWOMCD SPC MCD 190057 UTZ000-IDZ000-NVZ000-ORZ000-WAZ000-190600- MESOSCALE DISCUSSION 2581 NWS STORM PREDICTION CENTER NORMAN OK 0657 PM CST SUN DEC 18 2005 AREAS AFFECTED...SW WA/MUCH OF ORE/SW ID/NRN UT CONCERNING...FREEZING RAIN/SNOW VALID 190057Z - 190600Z ...FZRA WILL AFFECT THE INTERIOR VALLEYS OF NW ORE/SW WA TONIGHT WITH MODERATE/HEAVY SNOW FROM THE COLUMBIA GORGE SEWD TO SW ID/NRN UT... FIRST IN A SERIES OF UPPER IMPULSES IS NOW ROTATING ONSHORE WITH AN UPPER CIRCULATION CENTER APPARENT IN EVENING WATER VAPOR IMAGERY MOVING INTO SW ORE. STAGNANT COLD AIRMASS HAS BEEN TRAPPED WITHIN THE VALLEYS FOR THE PAST FEW DAYS...AND WITH STRONG LARGE SCALE ASCENT AND MOISTURE IN PLACE...FZRA WILL RESULT ACROSS SOME LOCATIONS TONIGHT. THERE HAS BEEN FZRA DURING THE LAST COUPLE OF HOURS AT SALEM AND IN EUGENE EARLIER. 00Z SOUNDING FROM SALEM SHOWED NEAR FREEZING TEMPS FROM ABOUT 925MB-750MB...BUT RECENT MODERATE SNOW REPORTS IN/NEAR PORTLAND INDICATE THE COLUMN IS COLD ENOUGH FOR SNOW AT LEAST INITIALLY. VEERING PROFILE FROM BOTH ORE UPPER AIR SOUNDINGS IMPLIES CONTINUED WARMING...WITH A MIX OF PCPN TYPES POSSIBLE. FORECAST SOUNDINGS FROM THE NAM/RUC SUGGEST FZRA COULD SPREAD FROM PORTLAND NWD INTO THE INTERIOR VALLEYS OF SW WA BY 03Z AND NEAR OLYMPIA TOWARD 06Z. THE PTYPE ALGORITHM AND THE NCEP SREF SHOW AN EVEN STRONGER SIGNAL OF FZRA...ESPECIALLY AFTER 06Z. ACROSS NERN PORTIONS OF ORE INTO ID/UT...SNOW IS EXPECTED WITH HRLY RATES OF 1 TO 2 INCHES PER HOUR POSSIBLE...AND BOUTS OF HEAVY SNOW WILL ALSO CONTINUE OVERNIGHT ACROSS THE WASATCH. ..TAYLOR.. 12/19/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...SLC...PIH...BOI...LKN...OTX...PDT...SEW...PQR... 41311512 44102090 44762407 46692299 47432121 45381690 41701120 40691196 WWWW From MCD at goshenarc.org Mon Dec 19 15:59:44 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 19 Dec 2005 10:59:44 -0500 Subject: [MCD] SWOMCD Message-ID: <200512191558.jBJFwCcW014407@mail.goshen.edu> ACUS11 KWNS 191557 SWOMCD SPC MCD 191557 IDZ000-ORZ000-WAZ000-192000- MESOSCALE DISCUSSION 2582 NWS STORM PREDICTION CENTER NORMAN OK 0957 AM CST MON DEC 19 2005 AREAS AFFECTED...ERN/NRN ORE...SERN WA...AND WRN ID CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION VALID 191557Z - 192000Z FREEZING RAIN WILL DIMINISH IN INTENSITY OVER THE WRN COLUMBIA RIVER GORGE THROUGH 18Z...WHILE A MIX OF SLEET AND FREEZING RAIN WILL DEVELOP FURTHER EAST OVER THE COLUMBIA RIVER BASIN OF NERN ORE/SERN WA THROUGH 20Z. HRLY ACCUMULATIONS UP TO 0.10 FOR AN HOUR OR TWO WILL BE POSSIBLE. FURTHER SOUTH...LIGHT SNOW WILL CONTINUE TO DEVELOP OVER THE TREASURE VALLEY OF FAR SERN ORE/SWRN ID THROUGH 18Z...BEFORE A MIX AND THEN CHANGE OVER TO SLEET/FREEZING RAIN OCCURS IN THIS AREA BETWEEN 18-20Z. ACCUMULATIONS RATES UP TO 0.10 INCH/HR WILL BE POSSIBLE IN THIS AREA AS WELL. STRONG MID LEVEL ISENTROPIC LIFT WAS CONTRIBUTING TO AN ORGANIZED NW-SE ORIENTED BAND OF PRECIPITATION MOVING EWD ACROSS SRN WA AND ERN ORE. AS THE UPPER WAVE CONTRIBUTING TO THIS LIFTS INTO BRITISH COLUMBIA...EXPECT A STEADY EWD PROGRESS OF THIS PRECIPITATION ACROSS MUCH OF NERN ORE/SERN WA THROUGH THE EARLY AFTERNOON HOURS. RECENT RUC/NAM FORECAST SOUNDINGS INDICATE THAT LIGHT SNOW WILL CHANGE OVER TO FREEZING RAIN OVER MUCH OF THE COLUMBIA RIVER BASIN OF NERN ORE/SERN WA THROUGH 20Z. FURTHER EAST...ISENTROPIC ASCENT WAS JUST NOW MOVING INTO THE UPPER TREASURE VALLEY OF SERN ORE/SWRN ID. IN THIS AREA...STRONG WAA...EVIDENT BY 60 KT SWLY JET AT 700 MB PER MEDFORD VWP...SUGGESTS THAT LIGHT SNOW NOW DEVELOPING INTO THIS AREA WILL CHANGE OVER TO FREEZING RAIN/SLEET BETWEEN 18-20Z. ..CROSBIE.. 12/19/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MSO...BOI...OTX...PDT...SEW...PQR... 46861735 47211930 47202100 46882142 46252177 45802181 45312147 45042090 44931996 44511932 43631865 42781781 42461733 42461578 43101540 44491601 46021678 WWWW From MCD at goshenarc.org Mon Dec 19 19:59:01 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 19 Dec 2005 14:59:01 -0500 Subject: [MCD] SWOMCD Message-ID: <200512191957.jBJJvR5N021293@mail.goshen.edu> ACUS11 KWNS 191956 SWOMCD SPC MCD 191956 IDZ000-ORZ000-WAZ000-200100- MESOSCALE DISCUSSION 2583 NWS STORM PREDICTION CENTER NORMAN OK 0156 PM CST MON DEC 19 2005 AREAS AFFECTED...NRN/ERN ORE...SWRN ID AND SRN WA- CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION VALID 191956Z - 200100Z MODERATE SNOW OVER THE TREASURE VALLEY MAY CHANGEOVER TO LIGHT FREEZING RAIN THROUGH 21Z...BEFORE WEAKENING TOWARDS 00Z. FURTHER NORTH MIXED PRECIP OVER NERN ORE/SERN WA...INCLUDING MUCH OF THE COLUMBIA RIVER BASIN...WILL CONTINUE TO DIMINISH THROUGH THE AFTERNOON. HOWEVER...A NEW AREA OF FREEZING RAIN WILL REDEVELOP AFTER 22Z IN THE DESCHUTES RIVER VALLEY OF NRN ORE AND OVER THE WRN COLUMBIA RIVER BASIN/GORGE AFTER 00Z. LATEST RADAR IMAGERY INDICATES A LARGE AREA OF PRECIPITATION OVER ERN ORE...ASSOCIATED WITH MODERATE-STRONG MID LEVEL WAA/ISENTROPIC LIFT. AS OF YET...THE WAA HAS BEEN INSUFFICIENT TO ALLOW FOR A CHANGEOVER TO FREEZING RAIN IN THE TREASURE VALLEY WITH MODERATE SNOWFALL THE PRIMARY P-TYPE. GIVEN RECENT TRENDS IN OBSERVATIONS AT BURNS /ELEV 4000 FT/ INDICATING ABOVE FREEZING TEMPERATURES DEVELOPING ...THERE IS STILL SOME POTENTIAL THAT SNOW WILL CHANGEOVER TO FREEZING RAIN BEFORE PRECIPITATION DIMINISHES BY LATE THIS AFTERNOON. FURTHER NW...RADAR IMAGERY AND SURFACE OBSERVATIONS INDICATE THAT WEAKENING MIXED PRECIP RATES WILL CONTINUE OVER MUCH OF THE COLUMBIA RIVER BASIN REGION THROUGH THE REMAINDER OF THE AFTERNOON AS MID LEVEL ISENTROPIC LIFT SHIFTS EWD AWAY FROM THE AREA. UPSTREAM OF THIS AREA...ANOTHER SURGE OF STRONG MID LEVEL WAA WAS BEGINNING AHEAD OF DEEP SYSTEM WELL OFF THE ORE COAST. THE ASSOCIATED PRECIPITATION WAS ALREADY ADVANCING NWD ALONG THE CENTRAL ORE COAST AND WILLAMETTE VALLEY. AS THIS PRECIPITATION ADVANCES NEWD...SUBFREEZING AIR WILL REMAIN IN PLACE OVER THE WRN COLUMBIA RIVER BASIN...COLUMBIA GORGE AND DESCHUTES VALLEY. THUS ANOTHER ROUND OF LIGHT TO MODERATE FREEZING RAIN WILL DEVELOP BETWEEN 22-01Z. ..CROSBIE.. 12/19/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MSO...BOI...OTX...PDT...SEW...PQR... 46911830 46751993 46592117 46392195 46222219 45492219 45042202 44252169 44302124 44962022 45081900 44701828 42881643 42671594 43311556 44691617 46701708 WWWW From MCD at goshenarc.org Tue Dec 20 01:32:42 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 19 Dec 2005 20:32:42 -0500 Subject: [MCD] SWOMCD Message-ID: <200512200131.jBK1VFQm000568@mail.goshen.edu> ACUS11 KWNS 200130 SWOMCD SPC MCD 200130 WAZ000-ORZ000-200630- MESOSCALE DISCUSSION 2584 NWS STORM PREDICTION CENTER NORMAN OK 0730 PM CST MON DEC 19 2005 AREAS AFFECTED...NERN ORE/ERN WA CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION VALID 200130Z - 200630Z FREEZING RAIN WILL CONTINUE TO DEVELOP OVER THE WRN COLUMBIA RIVER BASIN/GORGE OF NRN ORE THROUGH 03Z. FREEZING RAIN WILL EVENTUALLY DEVELOP INTO THE ERN SLOPES OF THE CASCADES AND COLUMBIA RIVER BASIN OF ERN WA BETWEEN 03-06Z. A COUPLE HOUR PERIOD OF HRLY PRECIP RATES UP TO 0.05 INCH WILL BE POSSIBLE...ESPECIALLY WITHIN 1-2 HOURS OF ONSET OF PRECIPITATION. AN AREA OF MOD-OCCASIONALLY HEAVY PRECIPITATION OVER NWRN ORE HAS DEVELOPED IN AN AREA OF MODERATE WAA AHEAD OF DEEP UPPER CYCLONE WELL OFF THE ORE COAST. THIS PRECIPITATION WILL CONTINUE TO SPREAD NEWD INTO THE COLUMBIA RIVER BASIN THROUGH THE LATE EVENING HOURS ON THE HEAL OF A 50-60 KT LOW LEVEL SSWLY JET. RECENT SURFACE OBSERVATIONS INDICATE HRLY RAINFALL RATES UP TO 0.2O INCH OVER THE NRN WILLAMETTE VALLEY. ALTHOUGH LOW LEVEL FLOW WILL REMAIN SSWLY WHICH SHOULD AID IN SOME SUBSIDENCE ON THE LEE-SIDE OF THE CASCADES...AND THUS LOWER HRLY PRECIP AMOUNTS...SUFFICIENTLY DEEP VERTICAL MOTION SHOULD ALLOW FOR LIGHT TO OCCASIONALLY MODERATE FREEZING RAIN TO DEVELOP INTO THE SERN SLOPES OF THE WA CASCADES AND COLUMBIA RIVER BASIN OF WA BETWEEN 03-06Z. FURTHER SOUTH...AS THE BULK OF THE LOW LEVEL LIFT/PRECIP CONTINUES TO MOVE NWD...EXPECT A DIMINISHING OF THE FREEZING RAIN RATES OVER THE DESCHUTES VALLEY THROUGH 06Z. ..CROSBIE.. 12/20/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...OTX...PDT...PQR... 47211981 47692030 47472102 47142094 46002160 45532231 45032185 44682168 44632070 44672056 45421981 46461970 WWWW From MCD at goshenarc.org Wed Dec 28 14:52:01 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 28 Dec 2005 09:52:01 -0500 Subject: [MCD] SWOMCD Message-ID: <200512281453.jBSErjeA027138@mail.goshen.edu> ACUS11 KWNS 281453 SWOMCD SPC MCD 281452 OHZ000-KYZ000-MIZ000-INZ000-TNZ000-ILZ000-281645- MESOSCALE DISCUSSION 2594 NWS STORM PREDICTION CENTER NORMAN OK 0852 AM CST WED DEC 28 2005 AREAS AFFECTED...E CENTRAL IL/IN/WRN OH/SRN LOWER MI/CENTRAL KY/NRN MIDDLE TN CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 281452Z - 281645Z THUNDERSTORMS SHOULD CONTINUE TO SPREAD ENEWD NEAR/JUST E OF EWD-MOVING UPPER LOW CENTER. MARGINALLY-SEVERE HAIL WILL REMAIN POSSIBLE WITH A FEW STRONGER CELLS...THOUGH WW NOT ANTICIPATED ATTM. LATEST RADAR IMAGERY SHOWS AN ARC OF STORMS NOW MOVING ENEWD ACROSS THE MIDDLE OH VALLEY REGION...JUST AHEAD OF UPPER LOW NOW CENTERED OVER SRN IL. COLD AIR ALOFT /AROUND -22 C AT 500 MB/ IS CONTRIBUTING TO AN ELEVATED LAYER OF STEEP LAPSE RATES...WITH 200 TO 400 J/KG MOST-UNSTABLE CAPE EVIDENT ON AREA 12Z RAOBS BETWEEN 850 AND 300 MB. WITH 40 TO 50 KT SSWLY FLOW AT MID LEVELS JUST AHEAD OF THE UPPER LOW...DEEP-LAYER SHEAR IS SUFFICIENT FOR SOME SUSTAINED/PERHAPS WEAKLY-ROTATING UPDRAFTS. THOUGH OVERALL STORM INTENSITY WILL REMAIN LIMITED DUE TO MARGINAL INSTABILITY...A FEW OF THE STRONGER STORMS WILL REMAIN CAPABLE OF PRODUCING 1/2 TO 3/4" HAIL OVER THE NEXT FEW HOURS AS STORMS SPREAD TOWARD ERN KY/WRN OH/SRN LOWER MI. ..GOSS.. 12/28/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...RLX...CLE...JKL...ILN...DTX...LMK...IWX...GRR...OHX...IND...LOT...ILX... 39978783 41858559 42148439 41818329 40768287 38528316 36768497 36158710 37758620 39168633 WWWW From MCD at goshenarc.org Wed Dec 28 17:20:25 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 28 Dec 2005 12:20:25 -0500 Subject: [MCD] SWOMCD Message-ID: <200512281722.jBSHM4oA027360@mail.goshen.edu> ACUS11 KWNS 281721 SWOMCD SPC MCD 281721 KYZ000-VAZ000-TNZ000-NCZ000-GAZ000-ALZ000-281915- MESOSCALE DISCUSSION 2595 NWS STORM PREDICTION CENTER NORMAN OK 1121 AM CST WED DEC 28 2005 AREAS AFFECTED...NRN AL/MIDDLE AND ERN TN/CENTRAL AND ERN KY CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 281721Z - 281915Z THREAT FOR HAIL/LOCALLY DAMAGING WINDS WILL LIKELY INCREASE OVER THE NEXT 1 TO 2 HOURS WITH STRENGTHENING STORMS. PARTS OF THIS AREA WILL BE MONITORED FOR POSSIBLE WW. AIRMASS CONTINUES TO DESTABILIZE AHEAD OF COLD FRONT...AS COOLING ALOFT ASSOCIATED WITH UPPER LOW CONTINUES TO OVERSPREAD WARMING/MOISTENING BOUNDARY LAYER. CONVECTION IS INCREASING IN INTENSITY ATTM OVER CENTRAL KY...WITH NEW CONVECTIVE DEVELOPMENT OCCURRING SWWD ACROSS MIDDLE TN AND INTO NRN AL. EXPECT THIS TREND TO CONTINUE AS FURTHER AIRMASS DESTABILIZATION OCCURS THROUGH THE AFTERNOON. THOUGH NOT AS STRONG AS FURTHER S...DEEP-LAYER SHEAR ACROSS THIS REGION IS SUFFICIENT TO SUPPORT ORGANIZED/WEAKLY-ROTATING UPDRAFTS. THIS COMBINED WITH SLOW INCREASE IN AVAILABLE INSTABILITY SUGGESTS THAT STORMS WILL BECOME CAPABLE OF PRODUCING MARGINALLY-SEVERE HAIL/WIND GUSTS OVER THE NEXT COUPLE OF HOURS. ..GOSS.. 12/28/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MRX...JKL...FFC...LMK...OHX...BMX...HUN... 37888507 38018400 37458304 34898443 33348728 35388627 36558592 WWWW From MCD at goshenarc.org Wed Dec 28 17:58:20 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 28 Dec 2005 12:58:20 -0500 Subject: [MCD] SWOMCD Message-ID: <200512281759.jBSHxw6K011500@mail.goshen.edu> ACUS11 KWNS 281759 SWOMCD SPC MCD 281758 GAZ000-FLZ000-ALZ000-282000- MESOSCALE DISCUSSION 2596 NWS STORM PREDICTION CENTER NORMAN OK 1158 AM CST WED DEC 28 2005 AREAS AFFECTED...SRN AL/FL PNHDL/SWRN INTO CENTRAL GA CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 281758Z - 282000Z SEVERE STORM THREAT FORECAST TO INCREASE ACROSS THIS REGION OVER THE NEXT SEVERAL HOURS. WW MAY BE REQUIRED. LATEST RADAR LOOP INDICATES AN AXIS OF THUNDERSTORMS EXTENDING FROM WRN NC SWWD ACROSS NRN GA INTO SERN AL -- WELL AHEAD OF SURFACE FRONT. AIRMASS DESTABILIZATION IS UNDERWAY ACROSS THE SURFACE WARM SECTOR/NEAR AND BEHIND THIS INITIAL LINE OF STORMS...AS MOISTENING BOUNDARY LAYER COUPLED WITH DAYTIME HEATING HAS IS NOW YIELDING MEAN-LAYER CAPE 500 TO 1000 J/KG. THOUGH CONVERGENCE REMAINS FAIRLY WEAK ALONG COLD FRONT ATTM AND NO OTHER OBVIOUS LOW-LEVEL CONVERGENCE AXES EXIST...LARGE-SCALE LIFT IS OCCURRING ACROSS THIS REGION AS SEVERAL WEAK FEATURES ALOFT ROTATE THROUGH THE BASE OF LARGER-SCALE MID-LEVEL TROUGH. WITH TIME...EXPECT MULTIPLE BANDS OF STORMS TO EVOLVE ACROSS THIS REGION. DEEP-LAYER SHEAR IS SUFFICIENT FOR ORGANIZED/SUPERCELL CONVECTION...WITH WSWLY MID-LEVEL FLOW NEAR 60 KT ABOVE SURFACE SSWLYS. THUS...EXPECT THREAT FOR HAIL AND LOCALLY DAMAGING WINDS TO INCREASE THROUGH THE AFTERNOON AS STORMS DEVELOP ACROSS THIS REGION. THOUGH LOW-LEVEL TURNING IS SOMEWHAT LIMITED...RAPID INCREASE IN FLOW WITH HEIGHT ABOVE THE SURFACE IS YIELDING 0-1 KM SHEAR SUFFICIENT FOR LOW-LEVEL ROTATION. THIS COMBINED WITH DEWPOINTS IN THE LOW 60S SUGGEST A THREAT FOR A TORNADO OR TWO AS WELL -- PARTICULARLY FROM SWRN GA SWWD. ..GOSS.. 12/28/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...CHS...JAX...FFC...TAE...BMX...MOB... 29808762 31548648 33418405 33508271 32408222 31158266 29578392 29518572 WWWW From MCD at goshenarc.org Wed Dec 28 20:18:12 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 28 Dec 2005 15:18:12 -0500 Subject: [MCD] SWOMCD Message-ID: <200512282019.jBSKJnMN008416@mail.goshen.edu> ACUS11 KWNS 282019 SWOMCD SPC MCD 282019 SCZ000-GAZ000-FLZ000-ALZ000-282215- MESOSCALE DISCUSSION 2597 NWS STORM PREDICTION CENTER NORMAN OK 0219 PM CST WED DEC 28 2005 AREAS AFFECTED...ERN AL/MUCH OF GA/W CENTRAL SC CONCERNING...TORNADO WATCH 898... VALID 282019Z - 282215Z SEVERE/TORNADO THREAT CONTINUES ACROSS MUCH OF WW -- PARTICULARLY NEAR AND E OF THE AL/GA BORDER. WITH SEVERAL SUPERCELLS NOW ONGOING ACROSS SWRN AND CENTRAL GA MOVING EWD...NEW WW MAY BE REQUIRED SHORTLY E OF CURRENT WW. LATEST RADAR IMAGERY SHOWS SEVERAL SEVERE/SUPERCELL STORMS ACROSS ERN AL AND INTO GA...AHEAD OF EWD-MOVING COLD FRONT. THOUGH NO TORNADOES HAVE BEEN CONFIRMED THUS FAR...LOW-LEVEL ROTATION REMAINS EVIDENT IN SEVERAL OF THE STRONGER STORMS. DEWPOINTS ARE GENERALLY IN THE UPPER 50S TO LOW 60S OVER WW AREA...CONTRIBUTING 500 TO 1000 J/KG MEAN-LAYER CAPE WITHIN AND JUST S OF WW. INSTABILITY DECREASES WITH EWD EXTENT ACROSS GA...AS SLY SURFACE TRAJECTORIES SOMEWHAT MORE ORIENTED OUT OF THE FL PENINSULA ARE MAINTAINING LOWER /MID 50S/ DEWPOINTS. NONETHELESS...AS REGION OF UVV EVIDENT ON WV IMAGERY OVER ERN AL/WRN GA /LIKELY THE LEFT EXIT REGION OF THE UPPER JET/ MOVES EWD WITH TIME...EXPECT STORMS TO ALSO SPREAD EWD TOWARD THE GA COAST/WRN SC. THOUGH SLOW WEAKENING TREND APPEARS LIKELY AS STORMS MOVE EWD INTO LESS UNSTABLE AIR...INSTABILITY SHOULD STILL BE SUFFICIENT TO SUPPORT VIGOROUS CONVECTION. THEREFORE...WITH A THREAT FOR AT LEAST HAIL AND DAMAGING WINDS LIKELY TO EXTEND E OF WW...NEW WW IS BEING CONSIDERED FOR ERN GA AND VICINITY. ..GOSS.. 12/28/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...CHS...CAE...JAX...FFC...TAE...BMX...MOB... 33538591 33868512 33808163 32388126 30678194 30718479 31728688 32448671 WWWW From MCD at goshenarc.org Wed Dec 28 22:57:42 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 28 Dec 2005 17:57:42 -0500 Subject: [MCD] SWOMCD Message-ID: <200512282259.jBSMxJkn004804@mail.goshen.edu> ACUS11 KWNS 282258 SWOMCD SPC MCD 282258 SCZ000-GAZ000-290030- MESOSCALE DISCUSSION 2598 NWS STORM PREDICTION CENTER NORMAN OK 0458 PM CST WED DEC 28 2005 AREAS AFFECTED...SERN GA/SRN AND CNTRL SC CONCERNING...TORNADO WATCH 899... VALID 282258Z - 290030Z THE SEVERE THREAT SHOULD CONTINUE ACROSS TORNADO WATCH 899 OVER THE NEXT FEW HOURS. THE SEVERE THREAT MAY ALSO EXPAND NEWD INTO CNTRL SC AS STRONG CELLS DRIFT NEWD LATE THIS AFTERNOON. WATER VAPOR IMAGERY CURRENTLY SHOWS A SHORTWAVE TROUGH OVER ERN GA EMBEDDED IN THE LARGER ERN US TROUGH. THIS FEATURE WILL CONTINUE TO MOVE NEWD THROUGH EARLY THIS EVENING ALLOWING THE LARGE CLUSTER OF STORMS OVER GA AND SRN SC TO EXPAND NWD. SFC DEWPOINTS DROP OFF QUICKLY FROM THE MID 50S F INTO THE 40S F EAST OF INTERSTATE 95. AS THE CONVECTION MOVES NEWD INTO THE COLUMBIA AREA...LARGE HAIL AND ISOLATED WIND DAMAGE WILL BE POSSIBLE WITH THE STRONGER CELLS. GRADUAL WEAKENING SHOULD OCCUR WITH THE STORMS THAT MOVE NEWD AND ENCOUNTER THE WEAKER INSTABILITY ACROSS ERN SC. ..BROYLES.. 12/28/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...ILM...CHS...CAE...JAX...FFC...TAE... 33777980 33207991 32048119 31248234 31468310 32128337 33438212 34238108 34208025 WWWW From MCD at goshenarc.org Thu Dec 29 18:28:50 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 29 Dec 2005 13:28:50 -0500 Subject: [MCD] SWOMCD Message-ID: <200512291830.jBTIUOkt026995@mail.goshen.edu> ACUS11 KWNS 291829 SWOMCD SPC MCD 291829 SDZ000-NDZ000-300030- MESOSCALE DISCUSSION 2599 NWS STORM PREDICTION CENTER NORMAN OK 1229 PM CST THU DEC 29 2005 AREAS AFFECTED...NORTHERN SOUTH DAKOTA...SOUTHERN NORTH DAKOTA CONCERNING...WINTER MIXED PRECIPITATION VALID 291829Z - 300030Z A SWATH OF MODERATE TO HEAVY SNOW LOCALLY PRECEEDED BY MIXED PRECIPITATION IS EXPECTED ACROSS NORTHERN SOUTH DAKOTA AND SOUTHERN NORTH DAKOTA THIS AFTERNOON WITH LOCALIZED SNOWFALL RATES APPROACHING ONE INCH PER HOUR. A UPPER LEVEL STRONG SHORT WAVE TROUGH EVIDENT IN WATER VAPOR IMAGERY AND RUC ANALYSES OVER CENTRAL COLORADO WILL PROGRESS EASTWARD AND COMBINE WITH LOW LEVEL CYCLOGENESIS TO PRODUCE DEEP LAYER ASCENT OVER THE THREAT AREA THIS AFTERNOON. STRONG 800-700 MB LAYER FRONTOGENESIS IN RUC FCST ALSO HELPS FOCUS ASCENT NEAR ND...SD BORDER AREA THIS AFTERNOON. AT 14Z... 105 KNOT WINDS AT 9KM WERE OBSERVED AT THE PLATTEVILLE CO WIND PROFILER AS THE JET STREAK AXIS SLID EASTWARD ACROSS COLORADO. SITUATION IS COMPLICATED BY A WEAKER LEAD SHORTWAVE CURRENTLY EVIDENT IN WV AND RUC ANALYSES OVER SW SD CURRENTLY CONTRIBUTING TO MODERATE SNOWFALL OVER SOUTHERN ND. BOTH RUC AND SREF APPEAR TO HAVE A POOR HANDLE ON THIS FEATURE. MODIFIED PACIFIC AIRMASS IS EVIDENT OVER PORTIONS OF NORTHWEST NEBRASKA AND EASTERN WY AND MT WITH GPS PW OF NEARLY THREE QUARTER INCH CURRENTLY OBSERVED NEAR CDR EARLIER TODAY. RUC AND NCEP SREF AGREE THAT LOCALIZED INCH PER HOUR SNOWFALL RATES ARE POSSIBLE...IN PARTICULAR LATE IN THE PERIOD. TYPICAL POLAR AIRMASS IS ABSENT ACROSS THE EASTERN US SO COOLING OF THE LAYER THROUGH DEEP ASCENT AND EVAPORATION WILL BE NECESSARY IN PORTIONS OF THE THREAT AREA BEFORE THE ONSET OF FROZEN PRECIPITATION. THE PRESENCE OF THE POORLY HANDLED LEAD SHORTWAVE COMBINED WITH OBSERVED MODERATE RAIN WITH ABOVE FREEZING TEMPERATURE AT MBG SD AT 18Z SHIFTED FOCUS OF WINTER PRECIPITATION SLIGHTLY NORTHWARD BUT CONFIRMS POTENTIAL FOR INCH AN HOUR RATES IN SNOW AREAS. 12Z ABR SOUNDING HAD ONLY A SHALLOW ABSOLUTELY STABLE LAYER WITH WET BULB TEMPERATURES ABOVE ZERO DESPITE 150MB DEEP LAYER WITH A DRY BULB TEMPERATURE ABOVE FREEZING. MODEL SOUNDINGS SUGGEST THAT PRECIPITATION WILL TRANSITION FROM FREEZING RAIN TO MIXED PRECIPITATION AND MAINLY SNOW OVER NORTHEAST SD BETWEEN 21 AND 03Z. HEAVIEST PRECIPITATION RATES WILL SPREAD FROM WEST TO EAST ACROSS THE THEAT AREA THIS AFTERNOON AND EVENING. ..SCHNEIDER.. 12/29/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...FGF...FSD...ABR...BIS...UNR... 45980223 46640089 46709924 46209760 45419681 43999689 45099843 45559949 45510117 WWWW From MCD at goshenarc.org Fri Dec 30 00:07:42 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 29 Dec 2005 19:07:42 -0500 Subject: [MCD] SWOMCD Message-ID: <200512300009.jBU09F5Y027398@mail.goshen.edu> ACUS11 KWNS 300008 SWOMCD SPC MCD 300008 IAZ000-MNZ000-WIZ000-SDZ000-NEZ000-300415- MESOSCALE DISCUSSION 2600 NWS STORM PREDICTION CENTER NORMAN OK 0608 PM CST THU DEC 29 2005 AREAS AFFECTED...SE SD...SRN MN...NRN IA CONCERNING...WINTER MIXED PRECIPITATION VALID 300008Z - 300415Z A LARGE AREA OF FREEZING RAIN MIXED WITH SNOW WILL SPREAD EWD AND GRADUALLY CHANGE OVER TO ALL SNOW ACROSS SE SD...SRN MN AND NRN IA. WATER VAPOR IMAGERY CURRENTLY SHOWS AN UPPER-LEVEL TROUGH OVER WRN SD AND WRN NEB WITH A DRY SLOT AND DEFORMATION ZONE EXPANDING EWD ACROSS ERN SD AND NE NEB. STRONG LIFT ASSOCIATED WITH THE LEFT FRONT QUADRANT OF THE MID-LEVEL JET AND STRONG DIVERGENCE ALOFT SHOWN ON THE SHORT-TERM MODEL FORECASTS IS RESULTING IN WIDESPREAD PRECIPITATION EXTENDING EWD FROM THE DEFORMATION ZONE. FORECAST SOUNDINGS ACROSS SRN MN AND NRN IA SHOW AN ABOVE FREEZING LAYER FROM 900 TO 800 MB. AS THE SYSTEM DRIFTS EWD TONIGHT THIS WARM LAYER WILL ERODE FROM WEST TO EAST RESULTING IN A CHANGEOVER TO ALL SNOW. ISOLATED HEAVY SNOWFALL RATES OF GREATER THAN 1 INCH PER HOUR WILL BE POSSIBLE ESPECIALLY AS THE WRAP AROUND ASSOCIATED WITH THE MID-LEVEL LOW DRIFTS EWD INTO SE SD AROUND MIDNIGHT. THIS AREA OF HEAVIER SNOWFALL SHOULD DRIFT EWD INTO SRN MN AND NRN IA DURING THE OVERNIGHT HOURS. ..BROYLES.. 12/30/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...ARX...MPX...DMX...FSD...OAX...ABR... 42689337 42759776 43299893 43989893 44699749 44759354 44239166 43159141 WWWW From MCD at goshenarc.org Fri Dec 30 00:17:19 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 29 Dec 2005 19:17:19 -0500 Subject: [MCD] SWOMCD Message-ID: <200512300018.jBU0IpuU030184@mail.goshen.edu> ACUS11 KWNS 300018 SWOMCD SPC MCD 300017 MNZ000-SDZ000-NDZ000-300615- MESOSCALE DISCUSSION 2601 NWS STORM PREDICTION CENTER NORMAN OK 0617 PM CST THU DEC 29 2005 AREAS AFFECTED...SE NORTH DAKOTA...NE SOUTH DAKOTA...WEST CNTRL MINNESOTA CONCERNING...HEAVY SNOW VALID 300017Z - 300615Z SNOWFALL RATES WILL APPROACH 1 INCH PER HOUR OVER SOUTHEAST NORTH DAKOTA...NORTHEAST SOUTH DAKOTA...AND WEST CENTRAL MINNESOTA. A LOW PRESSURE SYSTEM OVER CENTRAL SOUTH DAKOTA WILL CONTINUE TO MOVE EASTWARD INTO NORTHERN IOWA. THE UPWARD VERTICAL MOTION ASSOCIATED WITH A STRONG UPPER LEVEL WAVE MOVING THROUGH THE AREA...COUPLED WITH THE LEFT EXIT REGION OF A JET AND DECENT UPPER DIVERGENCE...WILL AID IN THE DEVELOPMENT OF SNOW BANDS AND HEAVY SNOW ACROSS THE REGION FOR MOST OF THE EVENING. MODERATE TO HEAVY SNOWFALL WILL BE THE MAJOR PRECIPITATION TYPE ACROSS THE NORTHERN PART OF THE REGION. ACCORDING TO THE GFS AND NAM...WHICH ARE IN FAIRLY GOOD AGREEMENT...SOME LOCALLY TRANSIENT SLEET AND FREEZING RAIN...ALONG WITH SNOW...WILL OCCUR IN THE SOUTHERN PART OF THE REGION. THE STORM SYSTEM WILL CONTINUE TO MOVE EASTWARD THROUGH THE PERIOD AND PRECIPITATION IS EXPECTED TO DECREASE TOWARDS FRIDAY MORNING. ..LEVIT.. 12/30/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MPX...FGF...ABR...BIS... 46900166 47170041 47209857 47209689 47049542 46209494 45659583 45369703 45269839 45300057 45680171 WWWW From MCD at goshenarc.org Fri Dec 30 05:40:11 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Fri, 30 Dec 2005 00:40:11 -0500 Subject: [MCD] SWOMCD Message-ID: <200512300541.jBU5fgb8004043@mail.goshen.edu> ACUS11 KWNS 300541 SWOMCD SPC MCD 300540 IDZ000-ORZ000-301145- MESOSCALE DISCUSSION 2602 NWS STORM PREDICTION CENTER NORMAN OK 1140 PM CST THU DEC 29 2005 AREAS AFFECTED...NERN OREGON INTO EXTREME SWRN ID CONCERNING...HEAVY SNOW VALID 300540Z - 301145Z MDT TO HVY SNOW IS EXPECTED TO DEVELOP BY AROUND 09Z MAINLY OVER NERN OREGON...WITH 1.50-2.00 IN/HR SNOW RATES POSSIBLE IN UPSLOPE REGION AND 1.00 IN/HR POSSIBLE LOWER ELEVATIONS. SNOW WILL THEN SHIFT EWD TOWARD 12Z INTO SWRN ID WHERE A MIXTURE OF RAIN AND HEAVY WET SNOW APPEAR LIKELY INTO THE LOWER TREASURE VALLEY. PRECIPITATION SHIELD IS EXPECTED TO GRADUALLY FILL IN ACROSS ERN OREGON AS SWLY FLOW BRINGS IN HIGHER PRECIPITABLE WATER CONTENT. UPWARD VERTICAL MOTIONS FIELDS WILL INCREASE AS ZONE OF FRONTOGENETICAL FORCING MATERIALIZES NEAR LEADING EDGE OF WARM/MOIST ADVECTION ALOFT. LIFTING ZONE IS EXPECTED TO LIE ALONG A NW-SE AXIS FROM THE MTNS OF NERN OREGON INTO FAR SWRN ID BY 12Z. RUC AND NAM FORECAST SOUNDINGS INDICATE STRONG VERTICAL MOTION CENTERED AROUND 550-500 MB LAYER WHICH IS COINCIDENT WITH FAVORABLE TEMPERATURE LAYER FOR DENDRITIC GROWTH. THIS...COMBINED WITH SATURATED AND SUB-ZERO PROFILES IN THE SFC-700 MB LAYER AND SURFACE WET BULB ZERO TEMPERATURES NEAR FREEZING SHOULD RESULT IN LOCALLY HEAVY SNOWFALL RATES...ESPECIALLY IN THE HIGHER TERRAIN WHERE SLY FLOW WILL ENHANCE UPSLOPE. PRECIPITATION MAY BEGIN AS RAIN IN THE LOWER TREASURE VALLEY...BUT COULD CHANGE TO HVY WET SNOW DURING HEAVIEST PRECIPITATION RATE PERIOD...WHICH WILL GENERALLY OCCUR AFTER 12Z. ..JEWELL.. 12/30/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...BOI...PDT... 44081904 44981929 45581858 45641758 45581746 45201696 44941673 44301665 43871676 43321698 43291819 43641860 WWWW From MCD at goshenarc.org Fri Dec 30 05:45:00 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Fri, 30 Dec 2005 00:45:00 -0500 Subject: [MCD] SWOMCD Message-ID: <200512300546.jBU5kVbb005506@mail.goshen.edu> ACUS11 KWNS 300546 SWOMCD SPC MCD 300545 MNZ000-IAZ000-WIZ000-SDZ000-NEZ000-300945- MESOSCALE DISCUSSION 2603 NWS STORM PREDICTION CENTER NORMAN OK 1145 PM CST THU DEC 29 2005 AREAS AFFECTED...ERN SD...SRN AND CNTRL MN...NRN IA CONCERNING...HEAVY SNOW VALID 300545Z - 300945Z AREAS OF HEAVY SNOW WILL CONTINUE ACROSS ERN SD...SRN AND CNTRL MN AND NRN IA DURING THE OVERNIGHT PERIOD. SNOWFALL RATES GREATER THAN 1 INCH PER HOUR WILL BE POSSIBLE IN THE HEAVIER SNOW BANDS. WATER VAPOR IMAGERY CURRENTLY SHOWS AN UPPER-LOW LOCATED ACROSS THE CNTRL DAKOTAS. A SHORTWAVE TROUGH EXTENDED SWD ACROSS CNTRL NEB WITH A DEFORMATION ZONE SETTING UP ACROSS WRN IA AND SERN SD. STRONG LIFT ASSOCIATED WITH THE TROUGH AND THE LEFT EXIT REGION OF THE MID-LEVEL JET WILL CONTINUE TO SUPPORT WIDESPREAD SNOWFALL ACROSS THE REGION OVERNIGHT. FORECAST SOUNDINGS ACROSS SRN MN...ERN SD AND NW IA SHOW THAT THE WARM LAYER BETWEEN 900 AND 800 MB THAT WAS PRESENT EARLIER HAS COOLED BELOW FREEZING IN MOST AREAS. AS A RESULT...SNOW WILL BE THE FAVORED MODE OF PRECIPITATION ALTHOUGH A FEW SPOTS OF FREEZING RAIN AND/OR SLEET WILL STILL BE POSSIBLE. THE STRONG LARGE-SCALE ASCENT AND ISENTROPIC LIFT NORTHEAST OF THE DEFORMATION ZONE WILL CONTINUE TO RESULT IN BANDS OF MODERATE TO HEAVY SNOW. THE HEAVIEST SNOWBANDS SHOULD BE ACROSS SE SD...FAR NRN IA AND SRN MN WHERE THE STRONGEST DIVERGENCE ALOFT SHOULD BE LOCATED. ..BROYLES.. 12/30/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...ARX...MPX...DMX...FSD...OAX...ABR... 42759727 43359805 44569811 45459724 45639572 45579387 44959255 43969202 42919279 42569537 42609557 WWWW From MCD at goshenarc.org Sat Dec 31 17:54:47 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sat, 31 Dec 2005 12:54:47 -0500 Subject: [MCD] SWOMCD Message-ID: <200512311756.jBVHuSXi030842@mail.goshen.edu> ACUS11 KWNS 311755 SWOMCD SPC MCD 311755 CAZ000-312000- MESOSCALE DISCUSSION 2604 NWS STORM PREDICTION CENTER NORMAN OK 1155 AM CST SAT DEC 31 2005 AREAS AFFECTED...SACRAMENTO VALLEY CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 311755Z - 312000Z ...LOW TOPPED SUPERCELLS MAY DEVELOP ACROSS THE SACRAMENTO VALLEY... LEADING EDGE OF STRONGER CVA IS SPREADING ACROSS THE COASTAL RANGE TOWARD THE SACRAMENTO VALLEY LATE THIS MORNING. MUCH DRIER MID LEVELS AND PARTIAL CLEARING ACROSS THE VALLEY WILL ALLOW FOR SOME HEATING OVER THE NEXT FEW HOURS..ALTHOUGH SFC TEMPS MAY STRUGGLE TO REACH THE LOWER 60S. UPSTREAM...LATEST DIAGNOSTIC DATA SUGGESTS STEEPER LOW-MID LEVEL LAPSE RATES...7C/KM...AND 3KM CAPE...IN EXCESS OF 100J/KG...WILL SPREAD INTO THE VALLEY ENHANCING THE PROSPECT FOR ROBUST CONVECTION. ADDITIONALLY...BACKED VALLEY FLOW SHOULD PROVE BENEFICIAL FOR SUSTAINING LOW-TOPPED CONVECTION...POSSIBLY AIDING STORM ROTATION AND SUPERCELL CHARACTERISTICS. HAIL IS THE MOST LIKELY SEVERE THREAT WITH THIS ACTIVITY...ALTHOUGH A BRIEF TORNADO IS ALSO POSSIBLE. ..DARROW.. 12/31/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...STO...MTR... 37662145 40252294 40862202 39452091 38192011 WWWW From MCD at goshenarc.org Sat Dec 31 18:31:35 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sat, 31 Dec 2005 13:31:35 -0500 Subject: [MCD] SWOMCD Message-ID: <200512311833.jBVIXGaU012212@mail.goshen.edu> ACUS11 KWNS 311832 SWOMCD SPC MCD 311832 CAZ000-312330- MESOSCALE DISCUSSION 2605 NWS STORM PREDICTION CENTER NORMAN OK 1232 PM CST SAT DEC 31 2005 AREAS AFFECTED...SIERRA MOUNTAINS CONCERNING...HEAVY SNOW VALID 311832Z - 312330Z HEAVY WET SNOW WILL CONTINUE/SPREAD SOUTHWARD ACROSS THE HIGHER ELEVATIONS OF THE SOUTHERN SIERRA MOUNTAINS THROUGH THE AFTERNOON. SNOW RATES OF 2-3 IN/HR WILL BE POSSIBLE...NAMELY ABOVE 7000-7500 FT. WATER VAPOR IMAGERY PORTRAYS COMPACT SHORTWAVE TROUGH/VORTICITY MAXIMA MOVING EASTWARD ALONG THE NORTHERN CA COAST. MESONET OBSERVATIONS GENERALLY INDICATE SNOW LEVELS AROUND 6000-6500 FT ACROSS THE NORTHERN SIERRAS /NORTH 0F I-80/...WITH 7000-7500 FT OR HIGHER SNOW LEVELS PROGRESSIVELY SOUTHWARD ACROSS THE CENTRAL/SOUTHERN SIERRAS. SNOW LEVELS SHOULD INITIALLY REMAIN RELATIVELY STEADY STATE ACROSS THE SOUTHERN SIERRAS ATTRIBUTABLE TO MODEST WARM AIR ADVECTION...BUT BEGIN LOWERING BY MID/LATE AFTERNOON AS CORE OF UPPER TROUGH/COLD POCKET TRANSITIONS EASTWARD. IN PRESENCE OF DPVA/STRONG OROGRAPHIC FORCING AND STEEPENING LAPSE RATES/CONVECTIVE ENHANCEMENT...HIGH PRECIPITABLE WATER ENVIRONMENT /1.23 PW PER SPECIAL 15Z OAKLAND ROAB -- 200+ PERCENT OF NORMAL/ WILL CONTRIBUTE TO HEAVY WET SNOW RATES OF 2-3 IN/HR OR GREATER...ESPECIALLY FOR W/SW FACING SLOPES OF THE SOUTHERN SIERRAS INTO EARLY EVENING. ..GUYER.. 12/31/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...VEF...REV...HNX...STO... 36661900 37351957 38552055 39292095 39342033 38401944 37341858 36751833 36261818 36191832 36251869 36351883 WWWW From MCD at goshenarc.org Thu Dec 1 06:32:22 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 01 Dec 2005 01:32:22 -0500 Subject: [MCD] SWOMCD Message-ID: <200512010630.jB16UgO4017705@mail.goshen.edu> ACUS11 KWNS 010630 SWOMCD SPC MCD 010629 IDZ000-NVZ000-ORZ000-011130- MESOSCALE DISCUSSION 2514 NWS STORM PREDICTION CENTER NORMAN OK 1229 AM CST THU DEC 01 2005 AREAS AFFECTED...SWRN ID / SERN OREGON / FAR NRN NV CONCERNING...HEAVY SNOW VALID 010629Z - 011130Z SNOW IS LIKELY TO INCREASE IN COVERAGE AND INTENSITY THROUGH THE NIGHT FROM SERN OREGON ACROSS NRN NV AND INTO SWRN ID. SNOW RATES NEAR 1 IN/HR WILL BE POSSIBLE. THERMAL GRADIENT WILL TIGHTEN A BIT ACROSS OREGON...NRN NEVADA...SRN IDAHO AND NRN UT AS WARM ADVECTION PERSISTS. RESULTING FRONTOGENETIC FORCING AND INCREASE IN PRECIPITABLE WATER VALUES IS EXPECTED TO INCREASE PRECIPITATION RATES ACROSS THE AREA. RUC AND NAM SOLUTIONS ARE IN GOOD AGREEMENT SUGGESTING HEAVIEST SNOW RATES MAY OCCUR OVER SWRN ID AND FAR NRN NV. FURTHER...THERMODYNAMIC PROFILES WILL FAVOR DENDRITIC AND AGGREGATE GROWTH. ..JEWELL.. 12/01/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...PIH...BOI...LKN... 41381454 41111603 41451793 41901888 42801848 42961763 43251681 42441469 42021415 WWWW From MCD at goshenarc.org Sat Dec 3 11:43:53 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sat, 03 Dec 2005 06:43:53 -0500 Subject: [MCD] SWOMCD Message-ID: <200512031142.jB3Bg5Lv001471@mail.goshen.edu> ACUS11 KWNS 031141 SWOMCD SPC MCD 031141 NYZ000-031545- MESOSCALE DISCUSSION 2515 NWS STORM PREDICTION CENTER NORMAN OK 0541 AM CST SAT DEC 03 2005 AREAS AFFECTED...W CNTRL NY CONCERNING...HEAVY SNOW VALID 031141Z - 031545Z LAKE EFFECT SNOW BAND/BANDS EMANATING FROM LAKE ONTARIO SHOULD PERSIST INTO THE AFTERNOON ACROSS W CNTRL NY FROM NEAR FULTON TO NEAR SYRACUSE AND ORISKANY. SNOWFALL RATES LOCALLY FROM 1 TO 1.5 INCHES PER HOUR MAY CONTINUE NEXT FEW HOURS. HOWEVER...INTENSITIES MAY GRADUALLY DECREASE THROUGH THE MORNING. LAKE EFFECT SNOW BANDS FROM FULTON TO ORISKANY ARE EXPECTED TO CONTINUE INTO THE AFTERNOON. THE BAND WAS MORE INTENSE EARLIER THIS MORNING WITH A SINGLE BANDED STRUCTURE BUT APPEARS TO HAVE WEAKENED SLIGHTLY AND BECOME LESS ORGANIZED DURING THE LAST HOUR. THIS BAND APPEARS TO HAVE MULTIPLE CONNECTIONS WITH TRAJECTORIES FROM LAKE SUPERIOR AND LAKE HURON AS WELL AS A FAIRLY LONG FETCH ACROSS LAKE ONTARIO. WNWLY BOUNDARY LAYER FLOW...VERY COLD TEMPERATURES WITH -13C AT 850 MB AND STEEP LOW LEVEL LAPSE RATES WILL PERSIST THIS MORNING OVER LAKE ONTARIO. HOWEVER...MID LEVEL HEIGHTS WILL CONTINUE TO RISE AND UPPER RIDGE WILL BUILD IN WAKE OF UPPER LOW LIFTING NWD THROUGH QUEBEC. BUILDING HEIGHTS WILL BE ACCOMPANIED BY WARMING IN THE 700 TO 750 MB LAYER AND A LOWERING OF INVERSION HEIGHTS WHICH SHOULD CONTRIBUTE TO LESS INTENSE BANDS WITH TIME. ..DIAL.. 12/03/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...ALY...BGM...BUF... 43557557 43067455 42567468 42877603 43207725 43617722 WWWW From MCD at goshenarc.org Sat Dec 3 18:27:49 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sat, 03 Dec 2005 13:27:49 -0500 Subject: [MCD] SWOMCD Message-ID: <200512031826.jB3IQ2t1019932@mail.goshen.edu> ACUS11 KWNS 031825 SWOMCD SPC MCD 031825 INZ000-ILZ000-WIZ000-IAZ000-MOZ000-NEZ000-KSZ000-040030- MESOSCALE DISCUSSION 2516 NWS STORM PREDICTION CENTER NORMAN OK 1225 PM CST SAT DEC 03 2005 AREAS AFFECTED...EXTREME NRN KS/SERN NEB/IA/SRN WI/NRN IL CONCERNING...HEAVY SNOW VALID 031825Z - 040030Z ...MODERATE TO HEAVY SNOW IS EXPECTED THIS AFTN ACROSS MAINLY SERN NEB/IA WITH SNOW INCREASING ACROSS SRN WI/NRN IL. HOURLY RATES WILL RANGE FROM 1 TO 2 INCHES... SEVERAL FACTORS WILL CONTRIBUTE TO BANDS OF MODERATE TO HEAVY SNOW THIS AFTN. ON THE SYNOPTIC SCALE...A SHORTWAVE TROUGH IS NOW LIFTING NEWD FROM KS/NEB...AND THIS PLACES THE ENTIRE AREA WITHIN A ZONE OF LARGE SCALE SLOPED ASCENT. SOME JET COUPLING IS ALSO LIKELY OCCURRING AS 12Z UPPER AIR ANALYSIS DEPICTS JET STREAK ACROSS SRN KS/MO AND ANOTHER DEPARTING JET MAX FROM IND INTO THE MID ATLANTIC. A BAND OF MODERATE TO HEAVY SNOW HAS BEEN ONGOING FOR THE LAST SEVERAL HOURS ACROSS SERN NEB INTO IA PER LOCAL RADAR IMAGERY...WITH MODERATE/HEAVY SNOW NOW EXTENDING FROM NEAR HARLAM IA TO JUST NORTH OF DSM...FROM AMES TO MARSHALLTOWN. FAVORABLE MID LEVEL FRONTOGENETICAL FORCING WILL ENCOURAGE NARROW BUT HEAVY MESOSCALE BANDS OF SNOW. THERMODYNAMIC PROFILES LOOK VERY SUPPORTIVE OF HEAVY SNOW...WITH FORECAST SOUNDINGS SUGGESTING DEEP LIFT THROUGHOUT THE DENDRITIC LAYER EXTENDING FROM 700-500MB. LATEST NAM GUIDANCE SUGGESTS HEAVIEST SNOWS WILL SET UP FROM ERN IA ALONG THE WI/IL BORDER BETWEEN 21Z-00Z. EXPERIMENTAL SHORT RANGE ENSEMBLE SOLN SUPPORTS THIS WITH MEAN 1 INCH PER HOUR RATES CONTINUING ACROSS MUCH OF CNTRL/ERN IA THIS AFTN BEFORE SPREADING TO NEAR MKE/ORD BY 04/00Z. ..TAYLOR.. 12/03/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LOT...MKX...DVN...ARX...DMX...EAX...OAX...TOP...GID... 41638865 39489733 40099833 41979563 43229242 43478986 43338758 41688715 WWWW From MCD at goshenarc.org Sat Dec 3 21:55:00 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sat, 03 Dec 2005 16:55:00 -0500 Subject: [MCD] SWOMCD Message-ID: <200512032153.jB3LrCVv006513@mail.goshen.edu> ACUS11 KWNS 032151 SWOMCD SPC MCD 032151 TNZ000-ALZ000-MSZ000-MOZ000-ARZ000-032345- MESOSCALE DISCUSSION 2517 NWS STORM PREDICTION CENTER NORMAN OK 0351 PM CST SAT DEC 03 2005 AREAS AFFECTED...ERN AR...WRN TN...NRN MS...NWRN AL CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 032151Z - 032345Z A WATCH MAY BE REQUIRED ACROSS PORTIONS OF THE LOWER/MIDDLE MS RIVER VALLEY AREA WITHIN 2 HOURS. WV SATELLITE IMAGERY WAS DEPICTING STRONG MID/UPPER LEVEL IMPULSE MOVING RAPIDLY EAST ACROSS THE SRN PLAINS LATE THIS AFTERNOON. SURFACE LOW PRESSURE WAS DEEPENING IN RESPONSE TO THIS IMPULSE AND WAS RECENTLY LOCATED OVER THE OZARKS OF SRN MO/NRN AR. IN ADDITION... A SHARP COLD FRONT WAS SPREADING STEADILY ESEWD FROM ERN OK AND WRN AR AS A WARM FRONT WAS RETREATING GRADUALLY NWD AHEAD OF THE SURFACE LOW...FROM NERN AR TO WRN TN TO NWRN AL. RECENT RUC AND ACARS SOUNDINGS ARE BEGINNING TO SUGGEST A GRADUAL EROSION OF THE CAPPING INVERSION IN THE 800-700MB LAYER ACROSS AR AS LARGE SCALE ASCENT/DPVA SPREADS EAST WITH THE MID/UPPER LEVEL SHORT WAVE TROUGH. HOWEVER...RECENT ACARS SOUNDINGS FROM MEM AREA ARE STILL INDICATING A RELATIVELY STRONG CAPPING INVERSION AT THE BASE OF THE ELEVATED MIXED LAYER AROUND 800MB. MEANWHILE...WARM SECTOR BOUNDARY LAYER FROM LA TO WRN TN CONTINUES TO WARM/MOISTEN WITH LATEST OBJECTIVE ANALYSIS DATA INDICATING 500-1000 MLCAPE IN THIS CORRIDOR. EXPECT THAT DEEP LAYER CONVERGENCE AND ADIABATIC COOLING ACCOMPANYING THE MID/UPPER IMPULSE AND ASSOCIATED COLD FRONT/SURFACE LOW WILL PROVE ADEQUATE TO LOCALLY OVERCOME INHIBITION ACROSS ERN AR WITHIN THE NEXT 1-2 HOURS. RESULTING STORMS WILL DEVELOP IN A STRONGLY SHEARED ENVIRONMENT WHERE SWLY/WSWLY FLOW ACROSS THE WARM SECTOR INCREASES TO OVER 50KT AT 850MB. THIS ENVIRONMENT WILL SUPPORT SUPERCELLS WITH HAIL AND WIND DAMAGE POTENTIAL POSSIBLY EVOLVING INTO A SQUALL LINE AS THE FRONT MOVES EAST ACROSS THE MS RIVER LATER THIS EVENING. ..CARBIN.. 12/03/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...OHX...HUN...MEG...JAN...LZK... 35119086 36208999 36398799 35268724 33848953 33209130 33349165 WWWW From MCD at goshenarc.org Sun Dec 4 01:00:04 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sat, 03 Dec 2005 20:00:04 -0500 Subject: [MCD] SWOMCD Message-ID: <200512040058.jB40wHKY025891@mail.goshen.edu> ACUS11 KWNS 040057 SWOMCD SPC MCD 040056 MDZ000-VAZ000-PAZ000-WVZ000-OHZ000-KYZ000-INZ000-040700- MESOSCALE DISCUSSION 2518 NWS STORM PREDICTION CENTER NORMAN OK 0656 PM CST SAT DEC 03 2005 AREAS AFFECTED...SRN IND/SRN OH/NRN KY/WV/WRN MD/NRN VA CONCERNING...FREEZING RAIN AND SLEET VALID 040056Z - 040700Z ...AREAS OF FZRA AND SLEET LIKELY THIS EVENING AND OVERNIGHT OVER PORTIONS OF THE OH VALLEY INTO THE CNTRL APPALACHIANS... ELEVATED CONVECTION/OVERRUNNING PCPN IS ALREADY MOVING NORTH OF THE OH RIVER...WHERE SFC TEMPS ARE AT OR BELOW FREEZING. WARMER TEMPERATURES WITHIN THE 750-800MB LAYER PER 00Z SOUNDINGS ARE RESULTING IN FREEZING RAIN ACROSS SRN IND/SRN OH. LARGE SCALE ASCENT WILL INCREASE AHEAD OF MID LEVEL SHORTWAVE NOW OVER THE UPPER MIDWEST. LATEST VAD WIND DATA FROM LOUISVILLE AND JACKSON KY INDICATE AT LEAST A 40-45 KT LLJ AROUND THE 1-2 KM AGL LAYER WITH 50 KT OBSERVED AT 850MB ON THE 00Z MEMPHIS SOUNDING. THE LLJ /850MB FLOW/ IS FORECAST TO INCREASE TO NEARLY 70KT BY 06Z WHICH WILL MAINTAIN STRONG WAA/ISENTROPIC LIFT ACROSS SRN OH/WV THIS EVENING. AMBIENT AIRMASS AT THE SFC IS VERY DRY...WITH DEWPOINTS IN THE TEENS IN MANY LOCATIONS. ALL THE SHORT TERM MODELS ARE TOO SLOW WITH BREAKING OUT PRECIPITATION GIVEN CURRENT TRENDS. HOWEVER RUC/NAM PTYPE ALGORITHMS DO AGREE THAT FZRA POSSIBLY MIXING WITH SLEET WILL DEVELOP ACROSS MUCH OF WV/NWRN VA/SRN OH AND POSSIBLY INTO SW PA THROUGH 04-06Z. FORECAST SOUNDINGS SUGGEST SOME OF THE HEAVIEST FZRA WILL LIKELY FALL AFTER 06Z ACROSS WV/NRN VA...WITH A STRONG INVERSION /+2 TO +4C/ NOTED IN THE 850-700MB LAYER ATOP A SUBFREEZING SFC AIRMASS. ..TAYLOR.. 12/04/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...CTP...LWX...RNK...PBZ...RLX...CLE...JKL...ILN...LMK...IWX...IND...PAH... 37467937 38178286 38498735 39488753 40328719 40157975 39767751 38517797 WWWW From MCD at goshenarc.org Sun Dec 4 01:18:07 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sat, 03 Dec 2005 20:18:07 -0500 Subject: [MCD] SWOMCD Message-ID: <200512040116.jB41GJpv032139@mail.goshen.edu> ACUS11 KWNS 040115 SWOMCD SPC MCD 040115 TNZ000-KYZ000-ILZ000-MOZ000-040315- MESOSCALE DISCUSSION 2519 NWS STORM PREDICTION CENTER NORMAN OK 0715 PM CST SAT DEC 03 2005 AREAS AFFECTED...EXTREME SERN MO...WRN/S CNTRL KY...NWRN/NRN MIDDLE TN CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 040115Z - 040315Z ELEVATED CONVECTION IS BEGINNING TO DEVELOP FROM SERN MO INTO EXTREME WRN KY AND NWRN TN. PARTS OF KY AND TN WILL BE MONITORED FOR INCREASING THUNDERSTORM DEVELOPMENT AND POSSIBLE WW. STRONG MID/UPPER LEVEL JET STREAK IS MOVING EWD ACROSS OK INTO AR...WITH INCREASING DYNAMIC FORCING FOR LARGE SCALE ASCENT APPROACHING THE LOWER OH VALLEY REGION. SWLY LOW LEVEL JET OF 45-55 KT EXTENDS FROM MS INTO MIDDLE TN...AND IS PROVIDING STRONG WARM ADVECTION LIFT ALONG AND NORTH OF THE WARM FRONT THAT CURVES FROM A LOW ALONG THE AR/TN BORDER SEWD INTO CENTRAL AL. RUC SOUNDINGS INDICATE PRESENCE OF ELEVATED INSTABILITY ABOVE THE COOL SURFACE LAYER NORTH/NORTHEAST OF THE SURFACE FRONT...AND ALTHOUGH MODEL LAPSE RATES ALOFT ARE MODEST...VERY STRONG DEEP LAYER SHEAR WILL ENHANCE UPDRAFT STRENGTH SUGGESTING POTENTIAL FOR HAIL FORMATION IN STRONGER CELLS. WE ARE MONITORING THIS AREA FOR POSSIBLE WW. ..WEISS.. 12/04/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MRX...JKL...LMK...OHX...PAH...MEG... 36818968 37298855 37568616 37508415 36848355 35958417 35748713 35668890 35848956 WWWW From MCD at goshenarc.org Sun Dec 4 01:46:41 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sat, 03 Dec 2005 20:46:41 -0500 Subject: [MCD] SWOMCD Message-ID: <200512040144.jB41isd0011981@mail.goshen.edu> ACUS11 KWNS 040143 SWOMCD SPC MCD 040143 PAZ000-NYZ000-WVZ000-OHZ000-MIZ000-INZ000-ILZ000-WIZ000-IAZ000-040645- MESOSCALE DISCUSSION 2520 NWS STORM PREDICTION CENTER NORMAN OK 0743 PM CST SAT DEC 03 2005 AREAS AFFECTED...CNTRL AND NRN IL/SERN WI/SRN LOWER MI/NRN IND/NRN OH/WRN PA CONCERNING...HEAVY SNOW VALID 040143Z - 040645Z PERIODS OF MODERATE TO OCNL HEAVY SNOW WILL CONTINUE ACROSS NRN AND CNTRL IL/SERN WI SPREADING INTO NRN IND/LOWER MI WITHIN THE NEXT FEW HOURS. HRLY SNOW RATES WILL BE AROUND 1 INCH. ACROSS CNTRL IL...A MIX OF FZRA AND SLEET IS EXPECTED FOR ANOTHER 1-2 HOURS. PCPN IS FILLING IN RAPIDLY ACROSS CNTRL/NRN IL IN RESPONSE TO INCREASING LARGE SCALE LIFT FROM UPSTREAM WAVE. MEANWHILE...ORIGINAL DEFORMATION BAND FROM EARLIER IN THE AFTN HAS MOVED INTO LOWER MI. 00Z SOUNDINGS FROM KILX /CENTRAL IL/ AND KILN /WILMINGTON OH/ BOTH SHOW A SUBTLE INVERSION...NEAR THE 750-800MB LAYER. TEMPERATURES ON THE CNTRL IL SOUNDING ARE MAINLY BELOW FREEZING WITH THE EXCEPTION OF A VERY SHALLOW WARM LAYER NEAR 800MB. THIS HAS BEEN SUFFICIENT TO ALLOW FOR FREEZING RAIN AT SEVERAL LOCATIONS. HOWEVER...FORECAST SOUNDINGS SUGGEST PCPN SHOULD CHANGE OVER TO SNOW WITHIN AN HOUR OR TWO. DOWNSTREAM...FZRA MAY PERSIST FOR A FEW HOURS THIS EVENING MAINLY SOUTH OF A MUNCIE/INDIANAPOLIS LINE /REFER TO MCD 2518 FOR MORE INFO/. ACROSS LOWER MI/NRN IND...PROFILES ARE COLD ENOUGH THROUGH A DEEP LAYER TO SUPPORT ALL SNOW. STRONG LIFT THROUGH A SATURATED DENDRITIC LAYER WILL CONTRIBUTE TO HEAVIER SNOW RATES...UP TO AN INCH PER HOUR. SNOW WILL EVENTUALLY SPREAD INTO WRN/CNTRL PA AROUND 06Z. ..TAYLOR.. 12/04/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...BUF...CTP...PBZ...CLE...ILN...DTX...IWX...GRR...IND...LOT...ILX...MKX...DVN... 40428707 39768875 39879009 40139047 40539079 41079075 42968936 43508837 43158233 42267936 40227986 40268031 40418478 WWWW From MCD at goshenarc.org Sun Dec 4 01:50:21 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sat, 03 Dec 2005 20:50:21 -0500 Subject: [MCD] SWOMCD Message-ID: <200512040148.jB41mWVF013748@mail.goshen.edu> ACUS11 KWNS 040147 SWOMCD SPC MCD 040147 COR MDZ000-VAZ000-PAZ000-WVZ000-OHZ000-KYZ000-INZ000-040700- MESOSCALE DISCUSSION 2518 NWS STORM PREDICTION CENTER NORMAN OK 0747 PM CST SAT DEC 03 2005 AREAS AFFECTED...SRN IND/SRN OH/NRN KY/WV/WRN MD/NRN VA CONCERNING...FREEZING RAIN AND SLEET VALID 040147Z - 040700Z CORRECTED FOR NASHVILLE SOUNDING ...AREAS OF FZRA AND SLEET LIKELY THIS EVENING AND OVERNIGHT OVER PORTIONS OF THE OH VALLEY INTO THE CNTRL APPALACHIANS... ELEVATED CONVECTION/OVERRUNNING PCPN IS ALREADY MOVING NORTH OF THE OH RIVER...WHERE SFC TEMPS ARE AT OR BELOW FREEZING. WARMER TEMPERATURES WITHIN THE 750-800MB LAYER PER 00Z SOUNDINGS ARE RESULTING IN FREEZING RAIN ACROSS SRN IND/SRN OH. LARGE SCALE ASCENT WILL INCREASE AHEAD OF MID LEVEL SHORTWAVE NOW OVER THE UPPER MIDWEST. LATEST VAD WIND DATA FROM LOUISVILLE AND JACKSON KY INDICATE AT LEAST A 40-45 KT LLJ AROUND THE 1-2 KM AGL LAYER WITH 50 KT OBSERVED AT 850MB ON THE 00Z NASHVILLE SOUNDING. THE LLJ /850MB FLOW/ IS FORECAST TO INCREASE TO NEARLY 70KT BY 06Z WHICH WILL MAINTAIN STRONG WAA/ISENTROPIC LIFT ACROSS SRN OH/WV THIS EVENING. AMBIENT AIRMASS AT THE SFC IS VERY DRY...WITH DEWPOINTS IN THE TEENS IN MANY LOCATIONS. ALL THE SHORT TERM MODELS ARE TOO SLOW WITH BREAKING OUT PRECIPITATION GIVEN CURRENT TRENDS. HOWEVER RUC/NAM PTYPE ALGORITHMS DO AGREE THAT FZRA POSSIBLY MIXING WITH SLEET WILL DEVELOP ACROSS MUCH OF WV/NWRN VA/SRN OH AND POSSIBLY INTO SW PA THROUGH 04-06Z. FORECAST SOUNDINGS SUGGEST SOME OF THE HEAVIEST FZRA WILL LIKELY FALL AFTER 06Z ACROSS WV/NRN VA...WITH A STRONG INVERSION /+2 TO +4C/ NOTED IN THE 850-700MB LAYER ATOP A SUBFREEZING SFC AIRMASS. ..TAYLOR.. 12/04/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...CTP...LWX...RNK...PBZ...RLX...CLE...JKL...ILN...LMK...IWX...IND...PAH... 37467937 38178286 38498735 39488753 40328719 40157975 39767751 38517797 WWWW From MCD at goshenarc.org Sun Dec 4 03:38:25 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sat, 03 Dec 2005 22:38:25 -0500 Subject: [MCD] SWOMCD Message-ID: <200512040336.jB43aYw8028052@mail.goshen.edu> ACUS11 KWNS 040336 SWOMCD SPC MCD 040335 TNZ000-ALZ000-MSZ000-ARZ000-LAZ000-040530- MESOSCALE DISCUSSION 2521 NWS STORM PREDICTION CENTER NORMAN OK 0935 PM CST SAT DEC 03 2005 AREAS AFFECTED...SWRN TN...SERN AR...NRN/CENTRAL MS...SWRN/SRN MIDDLE TN CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 040335Z - 040530Z CONVECTION APPEARS TO DEVELOPING ALONG THE SEWD MOVING FRONT OVER EXTREME NWRN MS...AND OVER PARTS OF SWRN AR. WW WILL LIKELY BE NEEDED BY 04Z. AIRMASS AHEAD OF THE FRONT IS WARM/MOIST WITH TEMPERATURES NEAR 70F AND DEW POINTS OF 60-65F. STRONG WSWLY WINDS ALOFT /500 MB FLOW OF 50-70 KT/ AND VEERING PROFILES IN THE LOWEST 1.5-2 KM AGL ARE CREATING A FAVORABLE ENVIRONMENT FOR ROTATING STORMS GIVEN PERSISTENT UPDRAFTS. 00Z ETA AND 02Z RUC BOTH INDICATE ADDITIONAL THUNDERSTORM DEVELOPMENT ALONG THE FRONT INTO THE OVERNIGHT HOURS. A NEW WATCH WILL LIKELY BE NEEDED TO BE ISSUED BY 04Z. ..WEISS.. 12/04/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...OHX...BMX...HUN...MEG...JAN...LZK...SHV... 33219334 34339117 35248958 35668906 35698807 35568749 35408686 34828708 34138765 33668810 32719031 31959268 31989328 32289373 32899398 WWWW From MCD at goshenarc.org Sun Dec 4 05:41:37 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sun, 04 Dec 2005 00:41:37 -0500 Subject: [MCD] SWOMCD Message-ID: <200512040539.jB45dmCk009703@mail.goshen.edu> ACUS11 KWNS 040539 SWOMCD SPC MCD 040538 VAZ000-TNZ000-KYZ000-040745- MESOSCALE DISCUSSION 2522 NWS STORM PREDICTION CENTER NORMAN OK 1138 PM CST SAT DEC 03 2005 AREAS AFFECTED...S CNTRL/SERN KY...NRN MIDDLE/NERN TN CONCERNING...SEVERE THUNDERSTORM WATCH 888... VALID 040538Z - 040745Z A BAND OF STRONG/SEVERE ELEVATED THUNDERSTORMS IS MOVING RAPIDLY EWD ACROSS NRN TN...IN ADVANCE OF A STRONG UPPER LEVEL SHORT WAVE TROUGH MOVING ACROSS THE MIDDLE MS VALLEY. WATER VAPOR IMAGERY SHOWS VERY PRONOUNCED DRYING/SUBSIDENCE ADVANCING INTO THE LOWER PARTS OF THE OHIO AND TN RIVER VALLEYS WITH LARGE SCALE ASCENT IMMEDIATELY DOWNSTREAM OVER PARTS OF KY AND TN. THE SYNOPTIC SCALE LIFT APPEARS CO-LOCATED WITH ZONE OF FORCED ASCENT ALONG THE SURFACE COLD FRONT...ENHANCING THUNDERSTORM ACTIVITY DESPITE MARGINAL ELEVATED INSTABILITY AOB 600 J/KG PER LATEST RUC SOUNDING. LARGE HAIL WILL BE THE PRIMARY SEVERE THREAT WITH THE STRONGEST CELLS. ADDITIONAL CONVECTION CONTINUES TO MOVE RAPIDLY EWD ACROSS SOUTH CENTRAL/SERN KY WHERE LOW LEVEL WARM ADVECTION ASSOCIATED WITH THE 50-60 KT LOW LEVEL JET LOCATED ACROSS TN INTO KY. MARGINALLY SEVERE HAIL REMAINS POSSIBLE ACROSS THIS AREA. ..WEISS.. 12/04/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MRX...JKL...LMK...OHX... 37358554 37448351 36008330 35838517 35858649 35898778 WWWW From MCD at goshenarc.org Sun Dec 4 06:07:01 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sun, 04 Dec 2005 01:07:01 -0500 Subject: [MCD] SWOMCD Message-ID: <200512040605.jB465DMt019161@mail.goshen.edu> ACUS11 KWNS 040604 SWOMCD SPC MCD 040604 NYZ000-NJZ000-PAZ000-MDZ000-DCZ000-VAZ000-WVZ000-OHZ000-041030- MESOSCALE DISCUSSION 2523 NWS STORM PREDICTION CENTER NORMAN OK 1204 AM CST SUN DEC 04 2005 AREAS AFFECTED...NRN WV/NRN VA/MD/PA/SRN NY/NRN NJ CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION VALID 040604Z - 041030Z POTENTIAL FOR SLEET/FREEZING RAIN AND SOME ICE ACCUMULATION WILL EXIST OVERNIGHT FROM NRN WV INTO WRN/CNTRL MD...SRN PA...AND PERHAPS FAR NRN VA. FURTHER NORTH...MAINLY LIGHT/MDT SNOW WILL SPREAD EWD ACROSS MUCH OF PA AND FAR SRN NY OVERNIGHT. WATER VAPOR IMAGERY DEPICTS LOW AMPLITUDE IMPULSE PROGRESSING EWD ACROSS THE OHIO/TENNESSEE VALLEYS...WITH ASSOCIATED FORCING FOR ASCENT AND WARM AIR ADVECTION/MOISTURE TRANSPORT RESULTING IN EWD SPREAD OF PRECIPITATION ACROSS OH/WV INTO PA/NRN VA/MD AT THIS TIME. ATTRIBUTABLE TO 50-60 KT LOW LEVEL JET /AS SAMPLED BY CHARLESTON WV AND STERLING VA WSR-88D VADS/...21Z SREF GUIDANCE/03Z RUC FCST SOUNDINGS SUGGEST ELEVATED WARM LAYER WILL BE MAINTAINED ABOVE SHALLOW COLD BOUNDARY LAYER. THIS SCENARIO WILL BE SUPPORTIVE OF FREEZING RAIN AND/OR SLEET WHERE SUB 32F SFC TEMPS ARE MAINTAINED...WHICH IS LIKELY ACROSS SRN PA...AND MUCH OF MD/FAR NRN VA PRIMARILY NW OF I-95 AND ALONG/NORTH OF I-66. FURTHER NORTH...SUFFICIENTLY COLD PROFILES WILL FAVOR LIGHT/MDT SNOW AS PREDOMINANT PRECIP TYPE ACROSS THE BULK OF PA INTO SRN NY OVERNIGHT. ALTHOUGH SNOW RATES SHOULD GENERALLY BE LESS THAN 1 IN/HR...CONVECTIVE ENHANCEMENT COULD YIELD LOCALLY HIGHER BURSTS MAINLY ACROSS CNTRL/SRN PA. OBSERVATIONAL TRENDS/SHORT TERM MODEL GUIDANCE SUGGEST LIGHT/MDT SNOW SHOULD SPREAD EWD INTO SE NY/NRN NJ BY 12Z. ..GUYER.. 12/04/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...OKX...ALY...PHI...BGM...BUF...CTP...LWX...PBZ...RLX...CLE... 42437502 42107429 41277422 40727454 40387505 39577628 38877714 38587875 38297997 38608044 39478084 41588037 42307898 WWWW From MCD at goshenarc.org Sun Dec 4 08:03:17 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sun, 04 Dec 2005 03:03:17 -0500 Subject: [MCD] SWOMCD Message-ID: <200512040801.jB481SrT024812@mail.goshen.edu> ACUS11 KWNS 040800 SWOMCD SPC MCD 040800 GAZ000-TNZ000-ALZ000-MSZ000-040930- MESOSCALE DISCUSSION 2524 NWS STORM PREDICTION CENTER NORMAN OK 0200 AM CST SUN DEC 04 2005 AREAS AFFECTED...NRN LA...SERN AR...N CNTRL MS...NRN AND CNTRL AL AND SERN TN CONCERNING...TORNADO WATCH 889... VALID 040800Z - 040930Z NRN PORTION OF SQUALL LINE FROM SERN TN THROUGH NERN AL IS EXPECTED TO GRADUALLY WEAKEN AS IT MOVES INTO NWRN GA. THE SWRN TWO THIRDS OF THE LINE SHOULD CONTINUE TO DEVELOP SEWD. CONVECTIVE TRENDS WILL BE MONITORED FOR A POSSIBLE WW ACROSS PARTS OF CNTRL AL. EARLY THIS MORNING A SQUALL LINE EXTENDS FROM SERN TN SWWD THROUGH NRN AL AND FARTHER SW INTO N CNTRL MS. A WARM/WEDGE FRONT EXTENDS FROM CNTRL GA NWWD THROUGH NERN AL WHERE IT INTERSECTS THE SQUALL LINE. STRONGEST PORTION OF THE LINE IS CURRENTLY MOVING THROUGH NRN AL WHERE SIGNIFICANT WIND DAMAGE HAS BEEN REPORTED. HOWEVER...NRN THIRD OF THE LINE SHOULD WEAKEN AND BECOME MORE ELEVATED AS IT CROSSES THE WEDGE FRONT AND MOVES OVER A MUCH MORE STABLE BOUNDARY LAYER IN NRN GA AND SE TN WHERE TEMPERATURES ARE IN THE 40S. FARTHER SW STORMS WILL HAVE A MUCH WIDER WARM SECTOR TO TRAVERSE. HOWEVER...THE BOUNDARY LAYER FLOW IS EXPECTED TO GRADUALLY WEAKEN AND VEER WITH TIME AS THE LOW LEVEL JET SHIFTS NEWD AWAY FROM THE WARM SECTOR. THE WEAKENING AND VEERING BOUNDARY LAYER FLOW SHOULD RESULT IN A GRADUAL DECREASE IN CONVERGENCE AND MAY SERVE AS AN OVERALL LIMITING FACTOR FOR SEVERE WEATHER LATER THIS MORNING. NEVERTHELESS...CONVECTIVE TRENDS WILL CONTINUE TO BE MONITORED FOR A POSSIBLE WW OVER CNTRL AL AS STORMS APPROACH THE ERN EDGE OF WW 889. ..DIAL.. 12/04/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MRX...FFC...BMX...HUN...MEG...JAN... 32999102 33668842 34418663 35088570 34758452 33898467 32918602 32548860 32619089 WWWW From MCD at goshenarc.org Sun Dec 4 16:17:07 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sun, 04 Dec 2005 11:17:07 -0500 Subject: [MCD] SWOMCD Message-ID: <200512041615.jB4GFIY5023414@mail.goshen.edu> ACUS11 KWNS 041614 SWOMCD SPC MCD 041614 MSZ000-LAZ000-TXZ000-041815- MESOSCALE DISCUSSION 2526 NWS STORM PREDICTION CENTER NORMAN OK 1014 AM CST SUN DEC 04 2005 AREAS AFFECTED...SWRN/CENTRAL LA INTO CENTRAL MS CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 041614Z - 041815Z SEVERE TSTM THREAT EXPECTED TO SLOWLY INCREASE THROUGH THE LATE MORNING/EARLY AFTERNOON. WW MAY BE REQUIRED BY THE EARLY/MID AFTERNOON. THUNDERSTORMS HAVE INCREASED DURING THE PAST HOUR IN A NE-SW ORIENTED AXIS FROM NEAR HEZ TO JUST SOUTHWEST OF LCH. 12Z SOUNDINGS FROM JAN AND LCH INDICATE AIR MASS IS NOW ONLY WEAKLY CAPPED...IF AT ALL...GIVEN CURRENT SFC TEMPERATURES IN THE LOWER 70S F AND DEW POINTS IN THE UPPER 60S F. MLCAPES ARE NOW IN THE 500-1000 J/KG RANGE...BUT WILL INCREASE INTO THE 1000-1500 J/KG BY THE MID AFTERNOON GIVEN FURTHER HEATING. LATEST SURFACE ANALYSES INDICATES SURFACE WAVE FORMING ALONG THE FRONT NEAR LFK WHICH WILL LIKELY DEVELOP SLOWLY EWD INTO CENTRAL LA AS COLD FRONT CONTINUES MOVING SOUTHEAST. THOUGH LARGE SCALE ASCENT ACROSS THE REGION WILL REMAIN WEAK...LOW LEVEL FOCUS ALONG FRONT AND NEAR MESO LOW SHOULD SUPPORT INCREASED THUNDERSTORM DEVELOPMENT ACROSS THIS GENERAL REGION. SWLY WINDS ALOFT ARE NOT EXPECTED TO STRENGTHEN TODAY OVER THIS AREA...HOWEVER EFFECTIVE SHEAR IS STILL ANTICIPATED TO BE SUFFICIENT FOR SUPERCELLS/SMALL BOW ECHOES WITH STRONGER CELLS IF INSTABILITY CAN DEVELOP AS EXPECTED. THEREFORE...SEVERE THREAT SHOULD SLOWLY INCREASE THROUGH THE LATE MORNING AND WW MAY BECOME NECESSARY LATER TODAY. ..EVANS.. 12/04/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...JAN...LIX...LCH...SHV... 29649341 30149415 31079349 31709144 31928984 30858957 29999135 WWWW From MCD at goshenarc.org Sun Dec 4 18:27:36 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sun, 04 Dec 2005 13:27:36 -0500 Subject: [MCD] SWOMCD Message-ID: <200512041825.jB4IPiKx018784@mail.goshen.edu> ACUS11 KWNS 041825 SWOMCD SPC MCD 041824 GAZ000-ALZ000-042000- MESOSCALE DISCUSSION 2527 NWS STORM PREDICTION CENTER NORMAN OK 1224 PM CST SUN DEC 04 2005 AREAS AFFECTED...AL INTO WRN GA CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 041824Z - 042000Z THE THREAT OF ISOLATED LARGE HAIL AND DAMAGING WINDS SHOULD INCREASE ALONG AND SOUTH OF SURFACE FRONT ACROSS THE AREA THIS AFTERNOON. TRENDS ARE BEING MONITORED FOR A WW. SATELLITE IMAGERY AND 18Z SURFACE ANALYSES INDICATE STRONG TEMPERATURE/HEATING GRADIENT ACROSS CENTRAL AL INTO NRN/CENTRAL GA. WELL DEFINED SURFACE FRONT IS EXPECTED TO CONTINUE SHIFTING SLOWLY SSEWD THROUGH THE DAY...WITH TEMPERATURES APPROACHING 80F TO ITS SOUTH. REGION REMAINS ALONG NERN EXTENT OF PRIMARY LOW LEVEL MOISTURE AXIS EXTENDING OUT OF THE LOWER MS RIVER VALLEY WITH SURFACE DEW POINTS IN THE LOWER 60S F. THIS IS LIMITING AVAILABLE INSTABILITY WITH CURRENT MLCAPES LESS THAN 1000 J/KG. HOWEVER... STRONG HEATING WITHIN WARM SECTOR WILL STEEPEN LOW LEVEL LAPSE RATES AND DEEP LAYER SHEAR REMAINS MORE THAN ADEQUATE FOR ORGANIZED STORMS INCLUDING SUPERCELLS/SMALL BOW ECHOES. THE POTENTIAL FOR ORGANIZED/SUSTAINED UPDRAFTS AND STEEP LOW LEVEL LAPSE RATES MAY OVERCOME LIMITED INSTABILITY AND SUPPORT MARGINALLY SEVERE HAIL AND ISOLATED DAMAGING WINDS. SEVERE THUNDERSTORM WATCH BEING CONSIDERED FOR PART OF THIS REGION. ..EVANS.. 12/04/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...FFC...TAE...BMX...MOB... 33338829 34098426 32818350 31918507 31398825 WWWW From MCD at goshenarc.org Sun Dec 4 20:14:28 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sun, 04 Dec 2005 15:14:28 -0500 Subject: [MCD] SWOMCD Message-ID: <200512042012.jB4KCbnM010778@mail.goshen.edu> ACUS11 KWNS 042011 SWOMCD SPC MCD 042011 ALZ000-MSZ000-LAZ000-TXZ000-042215- MESOSCALE DISCUSSION 2528 NWS STORM PREDICTION CENTER NORMAN OK 0211 PM CST SUN DEC 04 2005 AREAS AFFECTED...FAR SERN TX...LA...CENTRAL MS CONCERNING...SEVERE THUNDERSTORM WATCH 890... VALID 042011Z - 042215Z SEVERE THUNDERSTORMS WILL CONTINUE DEVELOPING WEST TO EAST ACROSS WW INTO THE EARLY EVENING. CONTINUE VALID PORTION OF WW. 19Z SURFACE ANALYSIS INDICATES SURFACE COLD FRONT HAS PROGRESSED SOUTH-SOUTHEASTWARD THIS AFTERNOON AND EXTENDS FROM NEAR MEI SWWD TO JUST OFF THE FAR SOUTHEAST TX COAST. INTERMITTENT SUPERCELL AND SMALL BOW ECHO STRUCTURES HAVE DEVELOPED ALONG BROKEN LINE OF STORMS NOW EXTENDING FROM CENTRAL LA INTO FAR SERN TX. AIR MASS REMAINS MODERATELY UNSTABLE FROM THE LOWER SABINE RIVER INTO CENTRAL LA WHERE RICHER GULF MOISTURE AND WARMER TEMPERATURES HAVE DEVELOPED. SURFACE-BASED CAPES OVER THIS AREA ARE CURRENTLY IN EXCESS OF 1000 J/KG...WITH MORE MARGINAL INSTABILITY NOW INTO CENTRAL MS. SHEAR ACROSS THE WHOLE REGION REMAINS QUITE STRONG...WITH EFFECTIVE SHEAR FROM 40-50 KT ACCORDING TO REGIONAL VWP/S. SEASONABLY COOL MID LEVEL TEMPERATURES WILL SUSTAIN A THREAT OF LARGE HAIL...ESPECIALLY WITHIN SWRN PORTION OF WW WHERE GREATER INSTABILITY SHOULD SUPPORT HAIL TO GOLF BALL SIZE IN THE STRONGER CORES. THE THREAT OF MARGINALLY SEVERE HAIL WILL ALSO CONTINUE BEHIND SURFACE COLD FRONT ACROSS NORTHERN PORTIONS OF WW /AND ADJACENT AREAS/ ALONG NOSE OF SWLY 35-40 KT LLJ. DAMAGING WINDS WILL ALSO REMAIN A HAZARD AS SMALL LINES EVOLVE IN A MORE N-S ORIENTATION ALONG AND AHEAD OF THE FRONT. ..EVANS.. 12/04/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...BMX...MOB...JAN...LIX...LCH...SHV... 28729404 30529398 33568824 31318833 WWWW From MCD at goshenarc.org Sun Dec 4 21:33:26 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sun, 04 Dec 2005 16:33:26 -0500 Subject: [MCD] SWOMCD Message-ID: <200512042131.jB4LVZZw015501@mail.goshen.edu> ACUS11 KWNS 042131 SWOMCD SPC MCD 042130 SCZ000-GAZ000-ALZ000-042300- MESOSCALE DISCUSSION 2529 NWS STORM PREDICTION CENTER NORMAN OK 0330 PM CST SUN DEC 04 2005 AREAS AFFECTED...CENTRAL AND NRN AL/GA INTO CENTRAL SC CONCERNING...SEVERE THUNDERSTORM WATCH 891... VALID 042130Z - 042300Z THREAT FOR SEVERE THUNDERSTORMS...INCLUDING ISOLATED SUPERCELLS...EXPECTED TO CONTINUE ACROSS WW. ISOLATED SEVERE THREAT ALSO EXPECTED TO PERSIST JUST EAST OF WW ACROSS THE SAVANNAH RIVER VALLEY. CONTINUE WW. THOUGH LARGE SCALE ASCENT REMAINS WEAK ACROSS THE REGION...SEASONABLY WARM/MOIST BOUNDARY LAYER HAS DEVELOPED AHEAD OF A COLD FRONT NOW MOVING SEWD ACROSS NRN GA INTO CENTRAL AL. DEW POINTS REMAIN IN THE LOWER 60S OVER MUCH OF THE SEVERE TSTM WATCH...WITH AXIS OF NEAR 60F DEW POINTS SPREADING INTO AGS DURING THE PAST HOUR OR TWO. DEEP LAYER SHEAR REMAINS QUITE STRONG WITH EFFECTIVE SHEAR FROM 45-55 KT ACROSS THE REGION...AND WILL SUSTAIN A FEW SUPERCELLS WITH PRIMARY THREATS OF LARGE HAIL/DAMAGING WINDS. SHEAR AND INSTABILITY PARAMETERS INDICATE THE SEVERE THREAT WILL LIKELY CONTINUE AHEAD OF THE COLD FRONT INTO E-CENTRAL GA/FAR WRN SC THROUGH SUNSET. WE WILL NEED TO MONITOR THIS AREA INTO THE EARLY EVENING FOR AN ADDITIONAL WW. ..EVANS.. 12/04/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...CHS...CAE...GSP...FFC...BMX...HUN...MOB... 31668818 33848766 34368197 33658077 32208266 WWWW From MCD at goshenarc.org Sun Dec 4 23:48:18 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sun, 04 Dec 2005 18:48:18 -0500 Subject: [MCD] SWOMCD Message-ID: <200512042346.jB4NkQMh013883@mail.goshen.edu> ACUS11 KWNS 042345 SWOMCD SPC MCD 042345 ALZ000-FLZ000-MSZ000-LAZ000-050145- MESOSCALE DISCUSSION 2530 NWS STORM PREDICTION CENTER NORMAN OK 0545 PM CST SUN DEC 04 2005 AREAS AFFECTED...SE LA...SRN MS...SRN AL...FAR WRN FL PANHANDLE CONCERNING...SEVERE THUNDERSTORM WATCH 890... VALID 042345Z - 050145Z AN ISOLATED SEVERE POTENTIAL MAY CONTINUE AS A CONVECTIVE CLUSTER MOVES EWD ACROSS SRN MS AND SRN AL THIS EVENING. A REPLACEMENT WW MAY BE REQUIRED ACROSS THE REGION. SFC ANALYSIS CURRENTLY SHOWS A COLD FRONT EXTENDING ENEWD JUST NORTH OF A LINE FROM NEAR BATON ROUGE LA TO NEAR HATTIESBURG MS TO MONTGOMERY AL. SFC DEWPOINTS SOUTH OF THE FRONT ARE IN THE LOWER TO MID 60S F AND DEWPOINTS MAY INCREASE OVER THE NEXT FEW HOURS DUE TO SLY WINDS. THIS COMBINED WITH LOW-LEVEL CONVERGENCE ALONG THE BOUNDARY MAY ALLOW A BOW ECHO AND CONVECTIVE CLUSTER CURRENTLY ALONG THE MS-LA STATE-LINE TO CONTINUE FOR 3 TO 5 MORE HOURS. AS A RESULT...THE POTENTIAL FOR SEVERE STORMS MAY INCREASE OVER FAR SRN MS AND SRN AL INTO THE FL PANHANDLE. 0-6 KM SHEAR VALUES AROUND 45 KT WITH INCREASING LOW-LEVEL FLOW DUE TO THE STRENGTHENING LOW-LEVEL JET SHOULD BE SUFFICIENT FOR AT LEAST A MARGINAL SEVERE THREAT WITH ISOLATED WIND DAMAGE AND HAIL POSSIBLE WITH THE STRONGER CELLS. HOWEVER...WITH THE LOSS OF DAYTIME HEATING...THE MAGNITUDE OF THE SEVERE THREAT REMAINS QUESTIONABLE. ..BROYLES.. 12/04/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...BMX...MOB...JAN...LIX...LCH... 30689171 31379055 31958851 32078712 31598652 30918642 30118705 29798923 29869132 30029151 WWWW From MCD at goshenarc.org Mon Dec 5 00:38:15 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sun, 04 Dec 2005 19:38:15 -0500 Subject: [MCD] SWOMCD Message-ID: <200512050036.jB50aP2x006103@mail.goshen.edu> ACUS11 KWNS 050035 SWOMCD SPC MCD 050035 NYZ000-050630- MESOSCALE DISCUSSION 2531 NWS STORM PREDICTION CENTER NORMAN OK 0635 PM CST SUN DEC 04 2005 AREAS AFFECTED...NRN NY CONCERNING...HEAVY SNOW VALID 050035Z - 050630Z ...SNOW RATES WILL BE AT LEAST 2 INCHES PER HOUR WITHIN MOST INTENSE PORTIONS OF LAKE EFFECT BAND DOWNWIND OF LAKE ONTARIO... LOCAL RADAR LOOPS INDICATE HEAVY SNOW IS ONGOING ACROSS OSWEGO AND LEWIS COUNTIES IN NRN NY SOUTH OF WATERTOWN. 00Z SOUNDING FROM BUFFALO INDICATES A FAVORABLE UNIDIRECTIONAL WIND PROFILE WITH WESTERLIES INCREASING TO AROUND 40-45 KT NEAR 700MB. WINDS WITHIN THE 850-700MB LAYER WILL CHANGE LITTLE IN DIRECTION OVER THE NEXT FEW HOURS...AND THIS WILL MAINTAIN A SINGLE BUT INTENSE BAND OF HEAVY SNOW. FORECAST GUIDANCE FROM THE SHORT TERM MODELS SUGGESTS THE BAND MAY FLUCTUATE A LITTLE TO THE NORTH OR SOUTH...BUT BASICALLY WILL REMAIN OVER OSWEGO/SRN LEWIS COUNTIES...AND POSSIBLY NRN ONEIDA. THE RUC AND 4KM WRF/NMM BOTH HINT THAT HEAVY SNOW BANDS WILL PERSIST THROUGH THE OVERNIGHT HOURS. ..TAYLOR.. 12/05/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...BTV...ALY...BGM...BUF... 43157632 43287745 43837723 44317513 44087418 42987451 42927487 WWWW From MCD at goshenarc.org Mon Dec 5 04:47:19 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sun, 04 Dec 2005 23:47:19 -0500 Subject: [MCD] SWOMCD Message-ID: <200512050445.jB54jUS0001649@mail.goshen.edu> ACUS11 KWNS 050444 SWOMCD SPC MCD 050443 GAZ000-ALZ000-050645- MESOSCALE DISCUSSION 2532 NWS STORM PREDICTION CENTER NORMAN OK 1043 PM CST SUN DEC 04 2005 AREAS AFFECTED...ERN AL...WRN AND CNTRL GA CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 050443Z - 050645Z AN ISOLATED WIND DAMAGE THREAT MAY EXIST AS A BOW ECHO MOVES EWD ACROSS ERN AL INTO WRN GA OVER THE NEXT FEW HOURS. A WW MAY NEED TO BE ISSUED WITHIN THE NEXT HOUR. SFC ANALYSIS SHOWS A SLOW MOVING COLD FRONT EXTENDING ENEWD ACROSS SRN MS INTO CNTRL GA. SOUTH OF THE BOUNDARY...SFC DEWPOINTS ARE IN THE MID 60S F WITH A THERMAL AXIS EXTENDING NWD FROM THE FL PANHANDLE INTO ERN AL. IN ADDITION...LIFT AND VERTICAL SHEAR MAY INCREASE OVER THE NEXT FEW HOURS AS A SHORTWAVE EVIDENT ON WATER VAPOR IMAGERY AND 60 KT MID-LEVEL JET EVIDENT ON OBJECTIVE ANALYSIS APPROACHES CNTRL GA. AS THIS OCCURS...A GRADUAL INTENSIFICATION OF THE LINE WILL BE POSSIBLE AND ISOLATED WIND DAMAGE AND/OR HAIL MAY OCCUR. ..BROYLES.. 12/05/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...FFC...TAE...BMX...MOB... 31748522 31738598 31898635 32148642 32468625 32778542 33028433 33268340 33058305 32618297 32358339 31848437 WWWW From MCD at goshenarc.org Mon Dec 5 08:43:49 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 05 Dec 2005 03:43:49 -0500 Subject: [MCD] SWOMCD Message-ID: <200512050841.jB58fu55013517@mail.goshen.edu> ACUS11 KWNS 050839 SWOMCD SPC MCD 050839 GAZ000-FLZ000-ALZ000-050945- MESOSCALE DISCUSSION 2533 NWS STORM PREDICTION CENTER NORMAN OK 0239 AM CST MON DEC 05 2005 AREAS AFFECTED...FL PANHANDLE...EXTREME SERN AL AND EXTREME SWRN GA CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 050839Z - 050945Z THREAT FOR ISOLATED TORNADOES AND DAMAGING WIND MAY PERSIST OVER THE WRN AND CNTRL FL PANHANDLE INTO EXTREME SERN AL AND SWRN GA NEXT FEW HOURS. A WW MIGHT BE NECESSARY FOR THIS AREA. PRE-FRONTAL LINE OF STORMS EXTENDS FROM SWRN GA THROUGH SERN AL INTO THE WRN FL PANHANDLE. INDIVIDUAL CELLS WITHIN THIS LINE ARE MOVING NEWD WHILE THE LINE MOVES SLOWLY EAST. A SURFACE BOUNDARY EXTENDS FROM THE NERN GULF NWWD THROUGH THE CNTRL AND WRN FL PANHANDLE. TORNADO THREAT MAY BE AUGMENTED AS STORMS MOVE NEWD WITHIN THE LINE AND INTERACT WITH THE BOUNDARY OVER THE FL PANHANDLE WHERE LOW LEVEL SHEAR/HELICITY IS LIKELY ENHANCED. ACTIVITY WILL LIKELY BECOME MORE ELEVATED AS IT CROSSES DEEPER INTO THE LOWER THETA-E AIR N OF THE BOUNDARY ACROSS SWRN GA. ..DIAL.. 12/05/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...TAE...MOB... 30488641 31298563 31608482 30958452 30278577  From MCD at goshenarc.org Mon Dec 5 12:58:50 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 05 Dec 2005 07:58:50 -0500 Subject: [MCD] SWOMCD Message-ID: <200512051256.jB5CuwMU005984@mail.goshen.edu> ACUS11 KWNS 051256 SWOMCD SPC MCD 051255 VAZ000-WVZ000-051700- MESOSCALE DISCUSSION 2534 NWS STORM PREDICTION CENTER NORMAN OK 0655 AM CST MON DEC 05 2005 AREAS AFFECTED...WRN/CNTRL VA AND FAR SE WV CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION VALID 051255Z - 051700Z SNOW IS EXPECTED TO DEVELOP/GRADUALLY INCREASE THIS MORNING ACROSS THE FAR SE WV/WRN VA APPALACHIANS INTO THE CNTRL VA PIEDMONT. IN SRN VA...INITIAL RAIN SHOULD BEGIN TO MIX WITH SNOW/SLEET BY 15Z-18Z. 12Z SURFACE/UPPER AIR ANALYSIS DEPICTS TIGHTENING BAROCLINIC ZONE ACROSS THE CNTRL APPALACHIANS REGION...WITH BROAD MOISTURE/ASCENT PLUME SPREADING NEWD ACROSS SRN VA AS LOW LEVEL CYCLONE GRADUALLY EVOLVES ALONG THE GA/SC BORDER. ALTHOUGH 35-40F SFC TEMPS ARE COMMON ACROSS MUCH OF WRN/CNTRL VA EARLY THIS MORNING...WITH SATURATION/TIGHTENING BAROCLINIC GRADIENT...THERMODYNAMIC PROFILES SHOULD COOL SUFFICIENTLY TO SUPPORT A RELATIVELY QUICK TRANSITION TO WET SNOW. THIS SCENARIO IS SUPPORTED BY MID LEVEL SATURATION/LOW LEVEL COOLING OBSERVED BETWEEN 00Z-12Z ROANOKE RAOBS...AS WELL AS SREF PRECIP-TYPE CONSENSUS AND 09Z RUC FCST SOUNDINGS. IN SRN VA...AFTER INITIAL BOUT OF RAIN...AFOREMENTIONED GUIDANCE SUGGESTS SLEET/SNOW SHOULD MIX IN BY MID/LATE MORNING ALONG A MARION-WYTHEVILLE-FARMVILLE-RICHMOND CORRIDOR. ..GUYER.. 12/05/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...AKQ...LWX...RNK...RLX...MRX... 38367818 38087744 37367727 36747905 36618002 36658192 37118194 37698089 WWWW From MCD at goshenarc.org Mon Dec 5 17:31:42 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 05 Dec 2005 12:31:42 -0500 Subject: [MCD] SWOMCD Message-ID: <200512051729.jB5HTqsD032086@mail.goshen.edu> ACUS11 KWNS 051728 SWOMCD SPC MCD 051728 GAZ000-FLZ000-ALZ000-051800- MESOSCALE DISCUSSION 2535 NWS STORM PREDICTION CENTER NORMAN OK 1128 AM CST MON DEC 05 2005 AREAS AFFECTED...ERN FL PANHANDLE INTO PARTS OF SWRN GA CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 051728Z - 051800Z ISOLATED SEVERE STORMS WILL BE POSSIBLE THIS AFTERNOON ACROSS THE ERN FL PANHANDLE INTO PARTS OF SWRN GA. IF THREAT APPEARS TO BECOME MORE WIDESPREAD...THEN A WW WOULD BE REQUIRED. REGIONAL RADARS SHOWED AN ISOLATED ROTATING STORM OVER LIBERTY COUNTY FL...WITH ADDITIONAL STORMS LOCATED ALONG/NEAR THE COLD FRONT FROM THE WRN FL PANHANDLE INTO SWRN GA. THE LIBERTY COUNTY STORM IS LOCATED IN THE WARM SECTOR WHERE SURFACE DEWPOINTS ARE MAINLY IN THE UPPER 60S. DESPITE WEAKER SURFACE WINDS/CONVERGENCE IN THIS REGION AHEAD OF THE FRONT...FAVORABLE DEEP LAYER AND LOW-LEVEL SHEAR /0-3 KM SRH NEAR 300 M2/S2/ VALUES CONTINUE TO SUPPORT ROTATING STORMS. MARGINAL INSTABILITY SHOULD...HOWEVER...LIMIT THE NUMBER OF STORMS THAT CAN ATTAIN PERSISTENT ROTATION AND ANY ATTENDANT SEVERE THREAT. ..PETERS.. 12/05/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...JAX...TAE... 29718626 30748540 31468450 31708367 31298291 30018327 29428415 29368524 WWWW From MCD at goshenarc.org Mon Dec 5 18:57:26 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 05 Dec 2005 13:57:26 -0500 Subject: [MCD] SWOMCD Message-ID: <200512051855.jB5ItZGK008668@mail.goshen.edu> ACUS11 KWNS 051854 SWOMCD SPC MCD 051854 NJZ000-PAZ000-DEZ000-MDZ000-VAZ000-DCZ000-WVZ000-060100- MESOSCALE DISCUSSION 2536 NWS STORM PREDICTION CENTER NORMAN OK 1254 PM CST MON DEC 05 2005 AREAS AFFECTED...MUCH OF VA/SE WV/NE MD AND THE ERN SHORE/DE/SRN NJ CONCERNING...HEAVY SNOW/WINTER PCPN TRENDS VALID 051854Z - 060100Z ...MODERATE TO HEAVY SNOW WILL CONTINUE ACROSS PORTIONS OF VA/WV...WITH SNOW RATES OF 1 TO 2 INCHES PER HOUR. SNOW WILL SPREAD INTO NRN VA AND MD THROUGH THE AFTN HOURS... LATEST WV LOOP SHOWS SHORT WAVE TROUGH NOW ACROSS OK/AR. THIS IMPULSE WILL TRACK INTO THE TN VALLEY/SRN APPALACHIANS LATER TONIGHT. SFC LOW IS NOW ANALYZED NEAR ATHENS GA...WITH A WARM FRONT LIFTING NWD ACROSS THE SC PIEDMONT. ETA HAS TRENDED TOWARD THE GFS SOLNS FOR THE PAST FEW RUNS...WITH THE SFC LOW TRACK CLOSER TO HATTERAS...BEFORE MOVING OUT TO SEA. WITH THIS SETUP...BAND OF HEAVIEST PCPN ASSOCIATED WITH UPPER DEFORMATION ZONE WILL BE FOCUSED ACROSS CNTRL INTO NE VA...EVENTUALLY SPREADING INTO SRN NJ/NE MD/DE BY EARLY EVENING. LATEST LOCAL/COMPOSITE RADAR ANIMATIONS SHOW A FAIRLY NARROW BAND OF MODERATE TO HEAVY SNOW EXTENDING FROM BLF/HSP/FVX/RIC. CLOSER TO THE VA/NC BORDER...TEMPS ARE WARM ENOUGH FOR RAIN. 17Z SPECIAL SOUNDINGS FROM DULLES AND NE OF BWI INDICATE THAT WHILE THE THERMODYNAMIC PROFILE IS COLD ENOUGH FOR SNOW...THERE IS STILL SOME DRY AIR THROUGH THE COLUMN. FORECAST SOUNDINGS SUGGEST SATURATION SHOULD OCCUR WITHIN THE NEXT COUPLE OF HOURS WITH ACCUMULATING SNOWS AFTER 21-22Z...ACROSS THE DC/BALTIMORE METRO AREAS...AND CLOSER TO 06/00Z TOWARD DOV/PHL. SUSTAINED MID LEVEL WARM ADVECTION IN THE 700-850MB MAY ALLOW SNOW TO CHANGE TO A SLEET/SNOW MIX LATER THIS AFTN ACROSS PORTIONS OF CNTRL VA CURRENTLY EXPERIENCING SNOW. FORECAST SOUNDINGS ACROSS NRN VA/SE WV/MD BECOME NEARLY ISOTHERMAL WITH STRONG ASCENT IN THE FAVORED DENDRITIC ZONE BY LATE AFTN/EVENING. THIS SHOULD SUPPORT MODERATE TO OCCASIONAL HEAVY SNOW RATES INTO THE EVENING. ..TAYLOR.. 12/05/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...PHI...AKQ...CTP...LWX...RNK...PBZ...RLX...MRX... 40487504 38638016 37228219 36658153 37407659 39307376 40007415 WWWW From MCD at goshenarc.org Mon Dec 5 20:42:48 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 05 Dec 2005 15:42:48 -0500 Subject: [MCD] SWOMCD Message-ID: <200512052040.jB5Keu1p008048@mail.goshen.edu> ACUS11 KWNS 052040 SWOMCD SPC MCD 052039 GAZ000-FLZ000-052215- MESOSCALE DISCUSSION 2537 NWS STORM PREDICTION CENTER NORMAN OK 0239 PM CST MON DEC 05 2005 AREAS AFFECTED...SRN GA/NRN FL CONCERNING...TORNADO WATCH 893... VALID 052039Z - 052215Z ISOLATED TORNADOES AND WIND DAMAGE REMAIN POSSIBLE ACROSS NRN FL AND SRN GA. AT 20Z...REGIONAL RADARS INDICATED THE STRONGEST STORMS WITH ROTATION WERE LOCATED OVER SRN GA IN CLINCH COUNTY...OVER LOWNDES COUNTY GA AND OFFSHORE OVER THE NERN GULF /60 W CTY/. THESE DISCRETE STORMS ARE MOVING NEWD AT 25-30 KT AND ARE LOCATED JUST EAST OF A LOW-TOPPED LEWP WHICH EXTENDED FROM SOUTH CENTRAL GA TO THE ERN FL PANHANDLE...JUST E OF TLH. LACK OF LIGHTNING WITH THE LEWP SUGGESTS THE STRONGEST STORMS WITH GREATEST SEVERE THREAT SHOULD REMAIN WITH THE DISCRETE ACTIVITY MOVING NEWD THROUGH THE MOISTURE/WEAK INSTABILITY AXIS OVER NWRN FL INTO SRN GA. DESPITE THE WEAK INSTABILITY...DEEP LAYER AND LOW-LEVEL SHEAR VALUES WILL CONTINUE TO SUPPORT A THREAT FOR ISOLATED TORNADOES AND/OR DAMAGING WINDS. A FEW STORMS MAY REMAIN STRONG ENOUGH TO RESULT IN A TORNADO THREAT EAST OF WW 893 INTO SERN GA/NERN FL. HOWEVER...GIVEN THE SMALL AREAL COVERAGE AND LIMITED THREAT...A NEW WW DOES NOT APPEAR LIKELY AT THIS TIME. ..PETERS.. 12/05/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...CHS...TBW...JAX...FFC...TAE... 29668497 30608375 31948306 32208239 31838181 30998160 30278172 29598232 29158321 WWWW From MCD at goshenarc.org Mon Dec 5 21:59:56 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 05 Dec 2005 16:59:56 -0500 Subject: [MCD] SWOMCD Message-ID: <200512052158.jB5Lw4CQ004999@mail.goshen.edu> ACUS11 KWNS 052157 SWOMCD SPC MCD 052157 FLZ000-GAZ000-052300- MESOSCALE DISCUSSION 2538 NWS STORM PREDICTION CENTER NORMAN OK 0357 PM CST MON DEC 05 2005 AREAS AFFECTED...SRN GA/NRN FL CONCERNING...TORNADO WATCH 893... VALID 052157Z - 052300Z ISOLATED TORNADOES AND/OR DAMAGING WINDS REMAIN POSSIBLE ACROSS VALID PART OF WW 893. LIGHTNING DATA/REGIONAL RADARS SUGGEST STRONGEST ACTIVITY IS LOCATED OFFSHORE OVER THE NERN GULF...WITH LINE OF THUNDERSTORMS MOVING EWD TOWARD THE NWRN FL GULF COAST /TAYLOR AND DIXIE COUNTIES/. RADAR DATA SHOWED EMBEDDED ROTATING STORMS OFFSHORE WITH THIS ACTIVITY...WHERE GREATEST CAPE WAS LOCATED. INSTABILITY IS WEAKER INLAND ACROSS NRN FL. THIS SHOULD LIMIT THE INLAND THREAT FOR ADDITIONAL SEVERE STORMS...EXCEPT ALONG THE COASTAL REGIONS WITH LAND FALLING STORMS. ..PETERS.. 12/05/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...TBW...JAX...TAE... 29798360 30488292 31158197 30228201 29578267 29228317 29248341 WWWW From MCD at goshenarc.org Mon Dec 5 23:19:06 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 05 Dec 2005 18:19:06 -0500 Subject: [MCD] SWOMCD Message-ID: <200512052317.jB5NHED0023745@mail.goshen.edu> ACUS11 KWNS 052316 SWOMCD SPC MCD 052316 FLZ000-060115- MESOSCALE DISCUSSION 2539 NWS STORM PREDICTION CENTER NORMAN OK 0516 PM CST MON DEC 05 2005 AREAS AFFECTED...COASTAL NW FL CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 052316Z - 060115Z ADDITIONAL WW NOT ANTICIPATED...BUT NARROW CORRIDOR OF SEVERE POTENTIAL MAY EXTEND SEWD ALONG FL GULF COAST AND ADJACENT WATERS...FROM WW 893 TO N OF PIE. STRONG/POSSIBLY SEVERE TSTMS OVER NERN GULF ARE EXPECTED TO MOVE INLAND AND WEAKEN...AS THEY ENCOUNTER INFLOW-LAYER AIR MASS THAT WILL STABILIZE BOTH WITH TIME AND WITH EWD EXTENT. SLGT POTENTIAL FOR DAMAGING WIND OR A TORNADO EXISTS OVER IMMEDIATE COASTAL AREAS...SE OF WW 893...FROM LEVY TO PASCO COUNTIES. VERTICAL SHEAR PROFILES -- ALREADY MARGINAL FROM TBW AREA SWD...ARE FCST TO WEAKEN WITH TIME ALONG ENTIRE W-CENTRAL/NW COAST OF FL AS BOUNDARY LAYER FLOW VEERS...SHRINKING 0-1 AND 0-3 KM AGL HODOGRAPHS. HOWEVER...THIS VEERING MAY ALLOW RELATIVELY BUOYANT BOUNDARY LAYER AIR NOW OFFSHORE TO ADVECT OVER COAST BEFORE PASSAGE OF PRIMARY CONVECTIVE BAND. MODIFIED RAOBS AND RUC SOUNDINGS INDICATE MLCAPES 200-500 J/KG ARE POSSIBLE BETWEEN CONVECTIVE BAND AND PASCO COUNTY THROUGH ABOUT 03Z. LEWP/BOW FORMATIONS NOW EVIDENT INVOF NARROW OFFSHORE CORRIDOR OF BUOYANCY MAY SURVIVE TO REACH COASTLINE BEFORE THEY WEAKEN. ..EDWARDS.. 12/05/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...TBW...JAX...TAE... 29308317 29538282 29488249 29058245 28608236 28238250 28188277 28278318 28508302 28668300 28778304 28818323 28948336 29168344 WWWW From MCD at goshenarc.org Tue Dec 6 00:29:47 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 05 Dec 2005 19:29:47 -0500 Subject: [MCD] SWOMCD Message-ID: <200512060027.jB60Rr91000449@mail.goshen.edu> ACUS11 KWNS 060027 SWOMCD SPC MCD 060026 ILZ000-IAZ000-MOZ000-KSZ000-NEZ000-060530- MESOSCALE DISCUSSION 2540 NWS STORM PREDICTION CENTER NORMAN OK 0626 PM CST MON DEC 05 2005 AREAS AFFECTED...SERN NEB/NERN KS/SRN IA/NRN MO CONCERNING...HEAVY SNOW VALID 060026Z - 060530Z ...BRIEF HEAVY/CONVECTIVE SNOW BURSTS ARE POSSIBLE IN ASSOCIATION WITH FAST MOVING SHORTWAVE TROUGH... LATE AFTN WATER VAPOR LOOPS CLEARLY SHOW SMALL BUT WELL DEFINED VORT MAX QUICKLY MOVING SEWD. THERE HAS BEEN A HISTORY OF MODERATE TO HEAVY SNOW RATES...WITH 20-40 MPH SFC WINDS AS THIS FEATURE MOVES BY. THE SNOW HAS LASTED JUST AN HOUR OR TWO IN MOST PLACES...WITH BRIEF HEAVY/CONVECTIVE SNOW BURSTS. PCPN WILL BE CLOSELY TIED TO UPPER FORCING...AND SINCE THE SYSTEM IS SO PROGRESSIVE...SIGNIFICANT SNOW ACCUMULATIONS ARE NOT EXPECTED. IN ADDITION...TEMPERATURES ARE FALLING SHARPLY...ON THE ORDER OF 12-15 DEGREES WITHIN AN HOUR. ..TAYLOR.. 12/06/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LSX...DVN...DMX...EAX...FSD...OAX...TOP...GID...LBF... 38949272 39829856 41509867 42349744 42139450 41799217 41269097 40259111 39279155 WWWW From MCD at goshenarc.org Tue Dec 6 01:31:56 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 05 Dec 2005 20:31:56 -0500 Subject: [MCD] SWOMCD Message-ID: <200512060130.jB61U3wm002064@mail.goshen.edu> ACUS11 KWNS 060129 SWOMCD SPC MCD 060129 MTZ000-WYZ000-IDZ000-060730- MESOSCALE DISCUSSION 2541 NWS STORM PREDICTION CENTER NORMAN OK 0729 PM CST MON DEC 05 2005 AREAS AFFECTED...WRN AND CNTRL MT CONCERNING...HEAVY SNOW AND NEAR BLIZZARD CONDITIONS VALID 060129Z - 060730Z ...MODERATE TO HEAVY SNOW WILL DEVELOP THIS EVENING INTO THE OVERNIGHT ACROSS CNTRL AND WRN MT WITH VERY STRONG POST FRONTAL WINDS CAUSING NEAR BLIZZARD CONDITIONS... UPPER LOW WILL MOVE SEWD ACROSS ALBERTA...ARRIVING AT THE INTERNATIONAL BORDER BY EARLY TUE MORNING. POTENT 120+KT JET STREAK WILL ALSO DIVE SWD ACROSS THE REGION. LARGE SCALE ASCENT WILL INCREASE IN RESPONSE TO STRONG CYCLONIC VORTICITY ADVECTION...RESULTING IN A PROLONGED PERIOD OF MODERATE TO HEAVY SNOW FOR THE DISCUSSION AREA. IN ADDITION...STRONG ARCTIC FRONT NOW FROM NEAR MSO TO SOUTH OF HLN WILL CONTINUE MOVING SWD THROUGH THE NIGHT. STRONG WINDS OF 20-40 MPH WITH HIGHER GUSTS WILL CREATE BLIZZARD CONDITIONS...ESPECIALLY IN AREAS WITH ONGOING MODERATE/HEAVY SNOW. ..TAYLOR.. 12/06/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...BYZ...RIW...TFX...MSO...OTX... 44631266 47241587 48731480 48571063 47250880 45210851 45020871 WWWW From MCD at goshenarc.org Wed Dec 7 11:27:51 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 07 Dec 2005 06:27:51 -0500 Subject: [MCD] SWOMCD Message-ID: <200512071125.jB7BPuSw023709@mail.goshen.edu> ACUS11 KWNS 071125 SWOMCD SPC MCD 071124 TXZ000-071630- MESOSCALE DISCUSSION 2542 NWS STORM PREDICTION CENTER NORMAN OK 0524 AM CST WED DEC 07 2005 AREAS AFFECTED...N CNTRL TX CONCERNING...WINTER MIXED PRECIPITATION VALID 071124Z - 071630Z PRECIPITATION IS EXPECTED TO GRADUALLY INCREASE ACROSS N CNTRL TX THROUGH THE MORNING. LIGHT FREEZING RAIN WILL BE POSSIBLE OVER THE WRN HALF OF N CNTRL TX BY MID MORNING. THE FREEZING RAIN MAY BEGIN TO MIX WITH SLEET OR SNOW BY LATE MORNING OR AFTERNOON. A COLD FRONT EXTENDS FROM SRN AR INTO N CNTRL TX NEAR FORT WORTH THEN SWWD INTO THE BIG BEND AREA. THIS FRONT WILL MOVE SEWD TODAY...ALLOWING COLD ARCTIC HIGH PRESSURE TO CONTINUE BUILDING INTO TX. POST FRONTAL WET BULB TEMPERATURES ARE WELL BELOW FREEZING OVER THE WRN PARTS OF N CNTRL TX. A 20-30 KT LOW LEVEL JET WILL PERSIST OVER CNTRL TX INTO THE AFTERNOON. THIS WILL MAINTAIN ISENTROPIC ASCENT AND WARM ADVECTION WITHIN THE 1-3 KM LAYER. THIS ASCENT IS ALREADY CONTRIBUTING TO AN INCREASE IN STRATUS AND PRECIPITATION OVER THE SRN HALF OF N CNTRL TX. OWING TO THE RELATIVE DRY BOUNDARY LAYER...MUCH OF THIS ACTIVITY IS NOT LIKELY REACHING THE GROUND IN POST FRONTAL REGION. EVAPORATIVE COOLING WILL EVENTUALLY SATURATE THE LAYER BELOW 3 KM AND MAINTAIN SURFACE TEMPERATURES BELOW FREEZING OVER THE WRN HALF OF N CNTRL TX. RUC SOUNDINGS VALID FOR EARLY THIS MORNING SHOW A WARM LAYER AROUND 2 KM...AND THIS PROFILE WILL LIKELY SUPPORT FREEZING RAIN AS SURFACE TEMPERATURES WET BULB BELOW ZERO. THIS WARM LAYER IS FORECAST TO GRADUALLY ERODE AS THE SUBZERO LAYER DEEPENS WITHIN THE POST FRONTAL ZONE. A CHANGEOVER OR MIX WITH SLEET AND SNOW WILL THEREFORE BE POSSIBLE. THE CHANGEOVER TO SNOW WILL BE MOST LIKELY OVER NWRN PARTS OF N CNTRL TX BY LATE MORNING...ESPECIALLY IF VERTICAL MOTION IS DEEP ENOUGH TO SATURATE THE LAYERS BELOW -10C WHERE DENDRITIC GROWTH IS FAVORED. BOTH ETA AND RUC FORECAST SOUNDINGS SHOW A SHALLOW UNSTABLE LAYER DEVELOPING BETWEEN 3 AND 5 KM BY MID-DAY...WHICH MAY CONTRIBUTE TO SOME CONVECTIVE ENHANCEMENT TO THE PRECIPITATION. ..DIAL.. 12/07/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...SHV...FWD...SJT... 33689593 32529547 32059669 31509814 31139904 31819913 33309755 WWWW From MCD at goshenarc.org Wed Dec 7 18:51:05 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 07 Dec 2005 13:51:05 -0500 Subject: [MCD] SWOMCD Message-ID: <200512071849.jB7InDen019718@mail.goshen.edu> ACUS11 KWNS 071848 SWOMCD SPC MCD 071848 OKZ000-TXZ000-080045- MESOSCALE DISCUSSION 2543 NWS STORM PREDICTION CENTER NORMAN OK 1248 PM CST WED DEC 07 2005 AREAS AFFECTED...CNTRL/NCNTRL TX...SRN OK CONCERNING...WINTER MIXED PRECIPITATION VALID 071848Z - 080045Z ...A WINTRY MIX OF PRECIPITATION WILL CONTINUE ACROSS THE SRN PLAINS. FREEZING RAIN WILL CONTINUE WELL INTO THE EVENING HOURS ACROSS PORTIONS OF THE DFW METROPLEX...SWD ALONG I-35... STRONG LOW LEVEL COLD ADVECTION CONTINUES ACROSS THE HILL COUNTRY THIS AFTERNOON...WITH SUB FREEZING TEMPERATURES NOW OBSERVED OVER MOST OF THE ESCARPMENT WEST OF I-35. SUSTAINED WARM ADVECTION ATOP THIS SHALLOW AIRMASS HAS AIDED RENEWED SHOWER DEVELOPMENT AS PRECIPITATION/SHALLOW CONVECTION EXPANDS NWD ACROSS NCNTRL TX INTO SRN OK. THESE TRENDS WILL LIKELY PERSIST WELL INTO THE EVENING HOURS BEFORE SUBSIDENT...DRYING AIRMASS DEVELOPS AND SPREADS ACROSS NWRN TX. LATEST TRENDS...AND FORECAST SOUNDINGS SUGGEST FREEZING RAIN WILL BE THE GREATEST WINTER THREAT ALONG THE I-35 CORRIDOR FROM JUST NORTH OF AUS...INTO THE DFW METROPLEX. NWRN PORTIONS OF THE METROPLEX HAVE TRANSITIONED TO SLEET. HOWEVER DOWNSTREAM...VERTICAL PROFILES REMAIN FAVORABLE FOR A PROLONGED FREEZING RAIN EVENT THAT SHOULD GENERATE HOURLY FREEZING RAIN TOTALS ON THE ORDER OF .02 IN...ESPECIALLY FROM DALLAS COUNTY TO HILL COUNTY. FARTHER NORTH...LIGHT SNOW IS DEVELOPING/SPREADING NWD ACROSS SRN OK. THIS PRECIPITATION WILL GRADUALLY INCREASE IN INTENSITY AS EVENING APPROACHES...BUT SNOW RATES SHOULD REMAIN WELL LESS THAN 1IN/HR. ..DARROW.. 12/07/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...TSA...FWD...OUN...EWX... 32239822 33669868 35799632 35189551 32889606 32069656 30979711 30329772 30459838 31289825 WWWW From MCD at goshenarc.org Thu Dec 8 01:23:36 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 07 Dec 2005 20:23:36 -0500 Subject: [MCD] SWOMCD Message-ID: <200512080121.jB81Lfjh010535@mail.goshen.edu> ACUS11 KWNS 080121 SWOMCD SPC MCD 080121 MOZ000-OKZ000-KSZ000-NEZ000-080515- MESOSCALE DISCUSSION 2544 NWS STORM PREDICTION CENTER NORMAN OK 0721 PM CST WED DEC 07 2005 AREAS AFFECTED...ERN KS/FAR NE OK/WRN MO CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION VALID 080121Z - 080515Z AREA OF LIGHT/OCNLY MDT SNOW WILL CONTINUE TO TRANSITION EWD ACROSS E KS/FAR NE OK INTO WRN MO THIS EVENING. RATES MAY REACH 1 IN/HR ON A LOCALIZED BASIS. DEEP ASCENT CONTINUES TO SPREAD EWD ALONG THE MISSOURI VALLEY AMIDST STRONG DIFFERENTIAL CVA/ISENTROPIC LIFT REGIME AHEAD OF WRN NEB/WRN KS CLOSED LOW. LIGHT/OCNLY MDT SNOW HAS PERSISTED MUCH OF THE AFTERNOON ACROSS ERN KS INTO THE KC METRO AREA...WITH SOMEWHAT CONCENTRATED BAND OF RELATIVELY HEAVIER SNOWFALL ONGOING EARLY THIS EVENING FROM ALONG/EAST OF THE KS TURNPIKE INTO THE KC METRO AREA. 00Z TOPEKA RAOB/21Z RUC BASED FCST SOUNDINGS FEATURE DEEPLY SATURATED THERMODYNAMIC PROFILES...WITH AMPLE UVVS COINCIDENT WITH RELATIVELY DEEP/FAVORABLE DENDRITIC GROWTH ZONE. COLD ARCTIC AIRMASS WILL PROMOTE SNOW TO LIQUID WATER RATIOS OF 15:1 OR PERHAPS 20:1. ..GUYER.. 12/08/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...SGF...EAX...TSA...OAX...TOP...ICT... 38659636 39249616 40299522 40309462 40079344 39179359 37699438 36839476 36529501 36559615 38179647 WWWW From MCD at goshenarc.org Thu Dec 8 12:10:35 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 08 Dec 2005 07:10:35 -0500 Subject: [MCD] SWOMCD Message-ID: <200512081208.jB8C8enO007241@mail.goshen.edu> ACUS11 KWNS 081208 SWOMCD SPC MCD 081207 KYZ000-INZ000-ILZ000-TNZ000-MOZ000-ARZ000-081600- MESOSCALE DISCUSSION 2545 NWS STORM PREDICTION CENTER NORMAN OK 0607 AM CST THU DEC 08 2005 AREAS AFFECTED...NERN AR...NWRN TN...SERN MO...SRN IL...WRN KY AND SRN IND CONCERNING...WINTER MIXED PRECIPITATION VALID 081207Z - 081600Z MOSTLY LIGHT SNOW ALONG WITH A MIX OF SOME FREEZING RAIN AND SLEET SHOULD CONTINUE FROM NERN AR THROUGH SERN MO...NWRN TN...WRN KY AND SRN IL THIS MORNING. PRECIPITATION RATES SHOULD GRADUALLY INCREASE ACROSS PARTS OF SERN IL INTO SRN IN AND WRN KY BY LATE MORNING INTO THE AFTERNOON. EARLY THIS MORNING A SHORTWAVE TROUGH AND INTENSIFYING MID LEVEL JET WERE MOVING EWD TOWARD THE LOWER/MID MS VALLEY. AN AREA OF MOSTLY LIGHT SNOW WITHIN THE ZONE OF ASCENT DOWNSTREAM FROM THIS FEATURE EXTENDS FROM NERN AR NWD INTO MO. A SLY LOW LEVEL JET IS FORECAST TO STRENGTHEN OVER THE TN VALLEY LATER THIS MORNING IN ASSOCIATION WITH INCREASING FORCING FOR ASCENT ACCOMPANYING THE INTENSIFYING MID LEVEL JET. THIS SHOULD ENHANCE LOW LEVEL MOISTURE TRANSPORT AS WELL AS ISENTROPIC ASCENT OVER SWRN PARTS OF THE OH VALLEY LATE THIS MORNING AND ESPECIALLY INTO THE AFTERNOON. SNOWFALL RATES MAY INCREASE TO NEAR 1 INCH PER HOUR FROM SERN IL...SRN IND INTO PARTS OF NWRN KY BY EARLY AFTERNOON. RUC FORECAST SOUNDINGS SHOW PRESENCE OF A WARM LAYER AROUND 1 KM FROM WRN KY INTO SRN IL AND SRN IND. THE PRECIPITATION MAY BRIEFLY START OUT AS MOSTLY FREEZING RAIN IN THESE AREAS...BUT SHOULD TRANSITION TO SLEET AND SNOW AS TEMPERATURES GRADUALLY WET BULB TO NEAR AND BELOW ZERO. THE SNOW/SLEET/FREEZING RAIN TRANSITION LINE IS EXPECTED TO REMAIN FAIRLY NARROW...EXTENDING FROM EXTREME NERN AR THROUGH NWRN KY. ..DIAL.. 12/08/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LMK...OHX...IND...PAH...ILX...MEG...LSX...LZK...SGF... 35389202 37299066 38948802 39178657 38488563 37408590 36918704 36018928 34679132 WWWW From MCD at goshenarc.org Thu Dec 8 18:04:07 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 08 Dec 2005 13:04:07 -0500 Subject: [MCD] SWOMCD Message-ID: <200512081802.jB8I2DCn008979@mail.goshen.edu> ACUS11 KWNS 081800 SWOMCD SPC MCD 081800 WVZ000-OHZ000-KYZ000-INZ000-ILZ000-090000- MESOSCALE DISCUSSION 2546 NWS STORM PREDICTION CENTER NORMAN OK 1200 PM CST THU DEC 08 2005 AREAS AFFECTED...OH VALLEY CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION VALID 081800Z - 090000Z A NARROW ZONE OF FREEZING RAIN...WITH RATES RANGING FROM .05-0.1 INCH PER HOUR...IS EXPECTED TO SPREAD NEWD ALONG THE OH RIVER VALLEY INTO SRN OH THIS AFTERNOON. THE HIGHEST RATES SHOULD BE 20-25 MILES EITHER SIDE OF A LINE FROM 30 E OWB TO 20 S LUK TO 30 ESE ZZV. SLEET MAY ALSO MIX IN WITH THE FREEZING RAIN AT TIMES...ESPECIALLY ALONG THE NRN PERIPHERY OF THIS REGION...AS PRECIPITATION TRANSITIONS TO SNOW. THIS MIXED PRECIPITATION SHOULD CHANGE TO MAINLY SNOW BY 21-23Z WEST OF A LINE FROM CMH TO CENTRAL KY. MEANWHILE...ALL SNOW IS EXPECTED NORTH OF THE ZONE OF FREEZING RAIN. SNOWFALL RATES WILL LIKELY INCREASE THROUGH THE AFTERNOON WITH RATES UP TO...AND AT TIMES...EXCEEDING 1 INCH PER HOUR. LARGE SCALE ASCENT WILL CONTINUE TO INCREASE THIS AFTERNOON ACROSS THE OH VALLEY AHEAD OF THE MID LEVEL SHORT WAVE TROUGH WHICH IS MOVING EWD TOWARD WRN IL THIS AFTERNOON. IN RESPONSE TO STRONG HEIGHT FALLS WITH THIS STORM SYSTEM...A SLY LLJ WILL STRENGTHEN TO 60-70 KT ACROSS THE TN VALLEY NOSING INTO NRN KY/SRN OH BY MID-LATE AFTERNOON. THE STRONG UVVS EXPECTED ACROSS IND/NRN KY INTO OH WILL AID IN SATURATING THE INITIALLY DRIER AIR MASS LOCATED BELOW 3 KM AS OBSERVED IN SWRN OH PER 12Z ILN SOUNDING. MOISTURE ADVECTION ALONG THE SLY LLJ WILL AID IN ADDITIONAL MOISTENING OF THE OH VALLEY AIR MASS. WAA ALONG THE NOSE OF THE LLJ IS EXPECTED TO SUPPORT A WARM LAYER BETWEEN 1-2 KM AGL SUFFICIENT FOR A NARROW BAND OF FREEZING RAIN AND AT TIMES MIXED WITH SLEET...GENERALLY ALONG THE IND/KY BORDER INTO FAR SWRN OH AND MUCH OF SOUTH CENTRAL TO SERN OH THIS AFTERNOON. SOUTH OF THIS ZONE OF FREEZING PRECIPITATION...SURFACE TEMPERATURES WILL CONTINUE TO RISE ABOVE 32 F...ALLOWING FOR A TRANSITION TO RAIN. AS THE SURFACE LOW...NOW LOCATED OVER NERN MS/WRN TN...TRACKS INTO ERN KY BY 09/00Z...COOLING IN THE 1-2 KM AGL LAYER GENERALLY WEST OF A LINE FROM CMH TO CENTRAL KY WILL SUPPORT THERMODYNAMIC PROFILES FOR ALL SNOW BY 21-23Z. ..PETERS.. 12/08/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...PBZ...RLX...CLE...JKL...ILN...LMK...IWX...IND...PAH...LOT...ILX... 38048680 38768850 40018833 40758684 41088542 41248441 40838286 40478171 40048124 39108125 38338179 37388335 37188454 37108603 WWWW From MCD at goshenarc.org Thu Dec 8 18:09:19 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 08 Dec 2005 13:09:19 -0500 Subject: [MCD] SWOMCD Message-ID: <200512081807.jB8I7Rbj012103@mail.goshen.edu> ACUS11 KWNS 081806 SWOMCD SPC MCD 081806 VAZ000-NCZ000-WVZ000-SCZ000-TNZ000-GAZ000-090000- MESOSCALE DISCUSSION 2547 NWS STORM PREDICTION CENTER NORMAN OK 1206 PM CST THU DEC 08 2005 AREAS AFFECTED...FAR NWRN SC / WRN NC / WRN VA` CONCERNING...FREEZING RAIN VALID 081806Z - 090000Z THE THREAT OF FREEZING RAIN WITH HOURLY RATES OF LESS THAN 0.05 INCH WILL DEVELOP ACROSS SRN PORTION OF DISCUSSION AREA LATE THIS AFTERNOON INTO EARLY EVENING. PRECIPITATION RATES ARE EXPECTED TO INCREASE TO 0.05-0.15 INCH/HOUR BY MID TO LATE EVENING ACROSS WRN PARTS OF NC/VA. REGIONAL VWPS AND SHORT TERM MODEL GUIDANCE INDICATE THAT PRIMARY BRANCH OF LLJ ASSOCIATED WITH WARM CONVEYOR BELT OF SYNOPTIC SYSTEM OVER THE LOWER MO VALLEY EXTENDED FROM THE CNTRL/ERN GULF COAST INTO THE TN VALLEY AS OF 17Z. WITH NEWD PROGRESSION OF MID-LEVEL LOW PRESSURE INTO THE OH VALLEY LATER THIS AFTERNOON INTO TONIGHT...SSELY LLJ WILL INTENSIFY TO 45-55 KTS ACROSS GA...THE CAROLINAS AND SRN/CNTRL APPALACHIANS. ENHANCED WAA AND ISENTROPIC ASCENT ALONG THIS FEATURE WILL LARGELY DRIVE NWD EXPANSION OF PRECIPITATION SHIELD CURRENTLY IN PLACE ACROSS CNTRL/SRN GA INTO SRN SC. BASED ON 12Z OBSERVED SOUNDINGS...CONSIDERABLE LOW-LEVEL MOISTENING WILL NEED TO OCCUR ACROSS DISCUSSION AREA PRIOR TO THE ONSET OF PRECIPITATION. HOWEVER BY 09/00Z...RUC/NAM FORECAST SOUNDINGS INDICATE SATURATION THROUGH THE LOWEST 3 KM AGL WITH A PRONOUNCED WARM NOSE DEVELOPING IN THE 1-2 KM LAYER. BASED ON CURRENT SURFACE OBSERVATIONS AND MODEL GUIDANCE...IT APPEARS THAT FREEZING RAIN WILL INITIALLY DEVELOP IN THE VALLEYS AND IMMEDIATE LEE OF THE GREAT SMOKEY MOUNTAINS AND BLUE RIDGE WHERE SURFACE COLD WEDGE IS EXPECTED TO PERSIST. FREEZING RAIN...PERHAPS MIXED WITH SLEET...WILL THEN DEVELOP NWD INTO PORTIONS OF WRN VA BETWEEN 09/00 AND 09/03Z. ..MEAD.. 12/08/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...RNK...RLX...GSP...MRX... 35488335 36948188 37388130 37138028 35958062 34908191 34668271 34798354 WWWW From MCD at goshenarc.org Fri Dec 9 00:56:53 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 08 Dec 2005 19:56:53 -0500 Subject: [MCD] SWOMCD Message-ID: <200512090054.jB90sw6T004800@mail.goshen.edu> ACUS11 KWNS 090054 SWOMCD SPC MCD 090054 PAZ000-MDZ000-WVZ000-VAZ000-OHZ000-MIZ000-INZ000-090700- MESOSCALE DISCUSSION 2548 NWS STORM PREDICTION CENTER NORMAN OK 0654 PM CST THU DEC 08 2005 AREAS AFFECTED...SRN MI / IN / OH / WRN PA / NRN WV / WRN MD / NWRN VA CONCERNING...HEAVY SNOW AND SLEET VALID 090054Z - 090700Z LARGE SHIELD OF PRECIPITATION CONTINUES TO MOVE NEWD ACROSS THE OH VALLEY. 1-2 IN/HR SNOWFALL RATES HAVE BEEN REPORTED...WITH HRLY LIQUID EQUIVALENTS BETWEEN 0.05-0.15 INCHES. GIVEN DEEPENING OF SURFACE LOW AS IT MOVES NEWD...AND CONTINUED STRONG MOISTURE ADVECTION OFF THE SURFACE...EXPECT HEAVY SNOW RATES TO BE MAINTAINED AS LARGE SCALE LIFT SHIFTS NEWD INTO WRN PA BY LATE EVENING. IT IS QUITE APPARENT FROM RADAR TRENDS AND MULTIPLE MODELS THAT HEAVIEST SNOW RATES WILL EXIST OVER SERN OH INTO SWRN PA. FARTHER S INTO ERN WV...NWRN VA...AND WRN MD...A MIXTURE OF SLEET AND SNOW IS EXPECTED DUE TO STRONG WARMING ALOFT. 00Z GSO SOUNDING SHOWS WARMING TEMPERATURES NOW ABOVE FREEZING BETWEEN 750-800 MB...AND THIS WILL ADVECT NEWD INTO ERN WV AND WRN MD WHERE PRECIPITATION SHOULD START OFF AS SNOW BUT WILL LIKELY CHANGE TO SLEET BY 06Z. ..JEWELL.. 12/09/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...CTP...LWX...RNK...PBZ...RLX...CLE...ILN...DTX...IWX...GRR...IND... 38068008 38048063 38368080 38518090 38968086 38948115 38968171 38978214 38968261 38798329 39088431 39688620 40378688 41488666 42228668 42448606 42348342 41968267 41438227 41377883 40977816 39767802 39147829 38247895 WWWW From MCD at goshenarc.org Fri Dec 9 00:59:38 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 08 Dec 2005 19:59:38 -0500 Subject: [MCD] SWOMCD Message-ID: <200512090057.jB90vhQf005960@mail.goshen.edu> ACUS11 KWNS 090057 SWOMCD SPC MCD 090056 VAZ000-NCZ000-WVZ000-TNZ000-090700- MESOSCALE DISCUSSION 2549 NWS STORM PREDICTION CENTER NORMAN OK 0656 PM CST THU DEC 08 2005 AREAS AFFECTED...SERN WV/CENTRAL AND SWRN VA/WRN NC CONCERNING...FREEZING RAIN VALID 090056Z - 090700Z FREEZING RAIN IS FORECAST TO OVERSPREAD THIS AREA OVER THE NEXT SEVERAL HOURS...WITH LOCAL RAINFALL RATES OF .05 TO .10"/HR. SOME SIGNIFICANT ICE ACCUMULATION IS EXPECTED. UPPER LOW CONTINUES MOVING ENEWD ACROSS THE MIDWEST/OH VALLEY...WITH A LARGE SSW-NNE BAND OF PRECIPITATION OCCURRING FROM AL NNEWD INTO THE MIDDLE OH VALLEY WITHIN WARM ADVECTION ZONE AHEAD OF UPPER LOW. STRONGEST WARM ADVECTION IS FORECAST TO SHIFT ACROSS THE APPALACHIANS AND INTO THE ATLANTIC COAST STATES THROUGH THIS EVENING...WITH SHARP AXIS OF QG FORCING DEPICTED ALONG AND JUST E OF THE APPALACHIAN CREST BY 09/06Z. WITH 1036 MB SURFACE HIGH ANALYZED ATTM ALONG THE MID-ATLANTIC COAST...STRONG WEDGE/DAMMING EVIDENT ATTM IN LEE OF THE MOUNTAINS WILL PERSIST THROUGH THE EVENING BENEATH STRONG SLY LOW-LEVEL JET /60 TO 70 KT/. THOUGH SURFACE WET-BULB TEMPERATURE ACROSS CENTRAL AND ERN NC WOULD SUGGEST MAINLY RAIN...ZONE OF BELOW FREEZING SURFACE TEMPERATURES SHOULD PERSIST WITHIN THE DISCUSSION AREA OVER CENTRAL AND SWRN VA INTO SERN WV AND SWD ACROSS WRN NC...THUS SUPPORTING FREEZING RAIN. NRN EXTENT OF FREEZING RAIN THREAT APPEARS LIKELY TO SET UP ACROSS CENTRAL VA...WHERE A TRANSITION TO SLEET SHOULD OCCUR. ..GOSS.. 12/09/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...AKQ...LWX...RAH...RNK...RLX...GSP...MRX... 37738111 38277977 38287860 37887769 37237814 36407922 36018074 35368254 35538297 36668161 WWWW From MCD at goshenarc.org Fri Dec 9 05:57:23 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Fri, 09 Dec 2005 00:57:23 -0500 Subject: [MCD] SWOMCD Message-ID: <200512090555.jB95tToq019600@mail.goshen.edu> ACUS11 KWNS 090554 SWOMCD SPC MCD 090554 NYZ000-CTZ000-NJZ000-PAZ000-DEZ000-MDZ000-VAZ000-DCZ000-WVZ000-NCZ000-091200- MESOSCALE DISCUSSION 2550 NWS STORM PREDICTION CENTER NORMAN OK 1154 PM CST THU DEC 08 2005 AREAS AFFECTED...SRN NY..WRN/CENTRAL PA...MD...WV AND VA AND NRN NC CONCERNING...WINTER MIXED PRECIPITATION VALID 090554Z - 091200Z SIGNIFICANT WINTER STORM WILL MOVE INTO THE MID ATLANTIC REGION OVERNIGHT. THREAT FOR HEAVY SNOW WILL DEVELOP NEWD ACROSS CENTRAL/ERN PA...FAR SRN NY...NJ AND WRN/NRN MD THROUGH 12Z. A MIX OF SLEET AND FREEZING RAIN WILL OCCUR SOUTH OF THIS REGION ACROSS PORTIONS OF NRN NC...MUCH OF CENTRAL/NRN VA...SRN/CENTRAL MD AND DE. SNOWFALL RATES FROM 1-2 IN PER HOUR WILL BE MOST LIKELY OVER ERN/CENTRAL PA AND NRN MD WITH THE GREATEST SLEET/FREEZING RAIN RATES UP TO 0.10 IN/HR IN A CORRIDOR FROM SWRN VA INTO THE DC METRO AREA/ERN MD BETWEEN 08-12Z. LATEST RADAR IMAGERY SHOWS AN EXTENSIVE AREA OF PRECIPITATION AHEAD OF A POWERFUL UPPER SYSTEM OVER THE OHIO VALLEY. STRONG MID LEVEL WARM ADVECTION/ISENTROPIC LIFT WILL CONTINUE TO CONTRIBUTE TO AN EXPANDING AREA OF PRECIPITATION OVER THE CENTRAL APPALACHIANS TOWARDS THE HUDSON RIVER VALLEY BY 12Z. STRONG ASCENT IN A THERMODYNAMIC PROFILE SUPPORTING DENDRITE SNOW GROWTH WILL SUPPORT HEAVY SNOWFALL WITH HRLY SNOWFALL RATES FROM 1-2 IN/HR ACROSS MUCH OF CENTRAL/ERN PA...WRN AND NRN MD INTO NJ/SRN NY THROUGH 12Z. FURTHER SOUTH STRONG LOW LEVEL WARM ADVECTION AHEAD OF A COLD FRONT WAS AIDING IN MODERATE PRECIPITATION ACROSS THE SRN APPALACHIANS...THAT WILL CONTINUE TO LIFT NEWD INTO THE MID-ATLANTIC. CURRENT WET BULB FREEZING LINE EXTENDING FROM THE SRN DELMARVA PENINSULA SWD INTO THE PIEDMONT REGION OF NC/SC WILL CONTINUE TO GRADUALLY SHIFT NWD THROUGH THE OVERNIGHT HOURS AS MODERATE PRESSURE FALLS WILL SUPPORT SELY LOW LEVEL FLOW. ELEVATED WARM LAYER WILL BE SUFFICIENTLY DEEP TO CONTINUE TO SUPPORT FREEZING RAIN OVER MUCH OF THE PIEDMONT REGION OF NC THROUGH 09Z...WHILE CONTINUING TO DEVELOP ACROSS MUCH OF SCENTRAL INTO ECENTRAL VA AND SRN MD THROUGH 12Z. NORTH OF THIS REGION...THERE WILL LIKELY CONTINUE TO BE A NARROW CORRIDOR OF ELEVATED WARM NOSE BETWEEN 850-800 MB THAT WILL SUPPORT A MIX OF SLEET WITH THE FREEZING RAIN FROM WCENTRAL/NRN VA INTO THE DC METRO AREA AND MUCH OF DE. ..CROSBIE.. 12/09/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...OKX...ALY...PHI...BGM...AKQ...BUF...CTP...LWX...RAH...RNK...GSP... 40697331 41667354 42107417 42377608 42227785 41337853 39257856 37777955 37138063 36208113 35848040 36797808 37837659 39067461 WWWW From MCD at goshenarc.org Fri Dec 9 06:00:32 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Fri, 09 Dec 2005 01:00:32 -0500 Subject: [MCD] SWOMCD Message-ID: <200512090558.jB95wbWR020652@mail.goshen.edu> ACUS11 KWNS 090557 SWOMCD SPC MCD 090557 COR NYZ000-CTZ000-NJZ000-PAZ000-DEZ000-MDZ000-VAZ000-DCZ000-WVZ000-NCZ000-091200- MESOSCALE DISCUSSION 2550 NWS STORM PREDICTION CENTER NORMAN OK 1157 PM CST THU DEC 08 2005 AREAS AFFECTED...SRN NY..ERN/CENTRAL PA...MD...WV AND VA AND NRN NC CONCERNING...WINTER MIXED PRECIPITATION VALID 090557Z - 091200Z CORRECTED STATE HEADER SIGNIFICANT WINTER STORM WILL MOVE INTO THE MID ATLANTIC REGION OVERNIGHT. THREAT FOR HEAVY SNOW WILL DEVELOP NEWD ACROSS CENTRAL/ERN PA...FAR SRN NY...NJ AND WRN/NRN MD THROUGH 12Z. A MIX OF SLEET AND FREEZING RAIN WILL OCCUR SOUTH OF THIS REGION ACROSS PORTIONS OF NRN NC...MUCH OF CENTRAL/NRN VA...SRN/CENTRAL MD AND DE. SNOWFALL RATES FROM 1-2 IN PER HOUR WILL BE MOST LIKELY OVER ERN/CENTRAL PA AND NRN MD WITH THE GREATEST SLEET/FREEZING RAIN RATES UP TO 0.10 IN/HR IN A CORRIDOR FROM SWRN VA INTO THE DC METRO AREA/ERN MD BETWEEN 08-12Z. LATEST RADAR IMAGERY SHOWS AN EXTENSIVE AREA OF PRECIPITATION AHEAD OF A POWERFUL UPPER SYSTEM OVER THE OHIO VALLEY. STRONG MID LEVEL WARM ADVECTION/ISENTROPIC LIFT WILL CONTINUE TO CONTRIBUTE TO AN EXPANDING AREA OF PRECIPITATION OVER THE CENTRAL APPALACHIANS TOWARDS THE HUDSON RIVER VALLEY BY 12Z. STRONG ASCENT IN A THERMODYNAMIC PROFILE SUPPORTING DENDRITE SNOW GROWTH WILL SUPPORT HEAVY SNOWFALL WITH HRLY SNOWFALL RATES FROM 1-2 IN/HR ACROSS MUCH OF CENTRAL/ERN PA...WRN AND NRN MD INTO NJ/SRN NY THROUGH 12Z. FURTHER SOUTH STRONG LOW LEVEL WARM ADVECTION AHEAD OF A COLD FRONT WAS AIDING IN MODERATE PRECIPITATION ACROSS THE SRN APPALACHIANS...THAT WILL CONTINUE TO LIFT NEWD INTO THE MID-ATLANTIC. CURRENT WET BULB FREEZING LINE EXTENDING FROM THE SRN DELMARVA PENINSULA SWD INTO THE PIEDMONT REGION OF NC/SC WILL CONTINUE TO GRADUALLY SHIFT NWD THROUGH THE OVERNIGHT HOURS AS MODERATE PRESSURE FALLS WILL SUPPORT SELY LOW LEVEL FLOW. ELEVATED WARM LAYER WILL BE SUFFICIENTLY DEEP TO CONTINUE TO SUPPORT FREEZING RAIN OVER MUCH OF THE PIEDMONT REGION OF NC THROUGH 09Z...WHILE CONTINUING TO DEVELOP ACROSS MUCH OF SCENTRAL INTO ECENTRAL VA AND SRN MD THROUGH 12Z. NORTH OF THIS REGION...THERE WILL LIKELY CONTINUE TO BE A NARROW CORRIDOR OF ELEVATED WARM NOSE BETWEEN 850-800 MB THAT WILL SUPPORT A MIX OF SLEET WITH THE FREEZING RAIN FROM WCENTRAL/NRN VA INTO THE DC METRO AREA AND MUCH OF DE. ..CROSBIE.. 12/09/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...OKX...ALY...PHI...BGM...AKQ...BUF...CTP...LWX...RAH...RNK...GSP... 40697331 41667354 42107417 42377608 42227785 41337853 39257856 37777955 37138063 36208113 35848040 36797808 37837659 39067461 WWWW From MCD at goshenarc.org Fri Dec 9 06:15:09 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Fri, 09 Dec 2005 01:15:09 -0500 Subject: [MCD] SWOMCD Message-ID: <200512090613.jB96DExJ025592@mail.goshen.edu> ACUS11 KWNS 090612 SWOMCD SPC MCD 090612 MIZ000-091015- MESOSCALE DISCUSSION 2551 NWS STORM PREDICTION CENTER NORMAN OK 1212 AM CST FRI DEC 09 2005 AREAS AFFECTED...SRN LOWER MI CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION VALID 090612Z - 091015Z HEAVY SNOW WITH HRLY RATES AROUND 1 INCH CENTERED ALONG THE I-96 CORRIDOR WILL GRADUALLY DIMINISH FROM WEST TO EAST THROUGH 10Z. MID LEVEL DEFORMATION ZONE EXTENDING ACROSS SRN LOWER MI WILL CONTINUE TO SHIFT EWD AS UPPER LOW CENTERED OVER NRN IND AT 06Z LIFTS NEWD INTO THE ERN GREAT LAKES THROUGH 12Z. THUS THE HEAVY SNOW BAND SHOULD GRADUALLY END OVER THE GRR AND MUSKEGON AREAS BY 09Z. IN ADDITION...DIMINISHING MID LEVEL MOISTURE TRANSPORT SHOULD SUPPORT A GRADUAL WEAKENING OF THE ERN PORTIONS OF DEFORMATION SNOW BAND LATER TONIGHT. HOWEVER...1 INCH/HR SNOWFALL RATES WILL BE LIKELY THROUGH 10Z ACROSS THE NRN DETROIT METRO AND FLINT AREAS. ..CROSBIE.. 12/09/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...DTX...GRR... 43198262 43188493 43048620 42648633 42318628 42238308 42748249 WWWW From MCD at goshenarc.org Fri Dec 9 13:02:15 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Fri, 09 Dec 2005 08:02:15 -0500 Subject: [MCD] SWOMCD Message-ID: <200512091300.jB9D0OxU018464@mail.goshen.edu> ACUS11 KWNS 091258 SWOMCD SPC MCD 091258 MEZ000-MAZ000-NHZ000-RIZ000-CTZ000-NYZ000-091730- MESOSCALE DISCUSSION 2552 NWS STORM PREDICTION CENTER NORMAN OK 0658 AM CST FRI DEC 09 2005 AREAS AFFECTED...PORTIONS CT...CENTRAL/ERN MA...RI...SRN/ERN NH...SRN MAINE CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION VALID 091258Z - 091730Z HEAVY SNOW IS EXPECTED TO SHIFT/SPREAD EWD ACROSS CENTRAL/ERN NEW ENGLAND THROUGH THE FORENOON HOURS. RATES 1-2 INCHES/HOUR SHOULD BE COMMON...WITH LOCAL 2-3 INCH/HOUR CONVECTIVE SNOW BURSTS EMBEDDED IN PRIMARY PRECIP PLUME. SFC MESOANALYSIS SHOWS COASTAL/MARINE FRONT FROM W-CENTRAL LONG ISLAND ENEWD TO VICINITY HYA AND NEWD INTO BAY OF FUNDY...WITHIN LESS THAN 10 NM S OF FREEZING LINE. EXPECT FRONT TO DRIFT SLOWLY NWD ACROSS COASTAL SERN MA AND CAPE COD AREAS. WAA ATOP SHALLOW FRONTAL LAYER JUST N OF SFC FRONT MAY MELT PRECIP SUFFICIENTLY TO YIELD NARROW/BRIEF CORRIDOR OF FREEZING RAIN FROM RI EWD ACROSS PYM AREA AND PORTIONS CAPE COD...WITH RATES REACHING TO NEAR .10 INCH/HOUR...BEFORE TRANSITIONING TO RAIN. INITIAL LIGHT-MODERATE SNOW...CHANGING TO HEAVY SNOW THEN MIX OF SNOW AND RAIN...IS EXPECTED IN IMMEDIATE FRONTAL ZONE OVER CENTRAL/ERN MAINE COAST AND ADJACENT ISLANDS. AMBIENT PRECIP SHIELD -- MOST INTENSE AT 12Z FROM SRN VT SWWD ACROSS NYC AREA TO DELMARVA REGION -- IS ASSOCIATED WITH INTENSE LOW LEVEL WAA AND MOISTURE TRANSPORT REGIME ELEVATED ATOP VERY COLD/STABLE BOUNDARY LAYER. THIS PRECIP PLUME WILL CONTINUE TO CONTAIN CONVECTIVE ELEMENTS AS IT SHIFTS ENEWD OVER MORE OF CENTRAL/ERN NEW ENGLAND...WITH HEAVY SNOW POSSIBLE AS FAR N AS N-CENTRAL NH...W-CENTRAL AND E-CENTRAL MAINE...AND LIKELY FROM ERN MA ACROSS SRN NH AND INLAND DOWN-EAST MAINE. MODIFIED RUC SOUNDINGS INDICATE EVAPORATIVE/SUBLIMATIVE COOLING OF INITIALLY DRY LOW-MIDLEVEL PROFILE WILL OFFSET WAA ENOUGH TO KEEP DEEP-LAYER THERMODYNAMIC PROFILES COLD ENOUGH TO GENERATE SNOW. MOISTURE TRANSPORT ASSOCIATED WITH 40-50 KT ELEVATED/SLY LLJ WILL HELP TO MAINTAIN PRECIP EFFICIENCY. ..EDWARDS.. 12/09/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...CAR...GYX...BOX...OKX...ALY... 41217350 43077219 44537095 45106980 45676771 45606758 45616747 45536741 45456750 45406742 45226743 45146733 45186716 44856691 44576740 43996840 43556992 42877062 42337093 41887052 41777026 41817012 41947009 42057023 42107020 42077001 41876986 41646989 41607011 41397094 40977350 WWWW From MCD at goshenarc.org Wed Dec 14 00:38:17 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Tue, 13 Dec 2005 19:38:17 -0500 Subject: [MCD] SWOMCD Message-ID: <200512140036.jBE0aQ8f030611@mail.goshen.edu> ACUS11 KWNS 140035 SWOMCD SPC MCD 140035 IAZ000-MNZ000-140430- MESOSCALE DISCUSSION 2553 NWS STORM PREDICTION CENTER NORMAN OK 0635 PM CST TUE DEC 13 2005 AREAS AFFECTED...SCNTRL MN...NCNTRL IA CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION VALID 140035Z - 140430Z A BRIEF PERIOD OF LIGHT FREEZING RAIN COULD OVERSPREAD PORTIONS OF NCNTRL IA AND SCNTRL MN OVER THE NEXT FEW HOURS. LIGHT GLAZE AMOUNTS MAY CAUSE HAZARDOUS DRIVING CONDITIONS BEFORE A CHANGEOVER TO LIGHT SNOW. A SWATH OF PRIMARILY LIGHT RAIN WAS DEVELOPING ENEWD ACROSS THE MO RIVER VALLEY THIS EVENING. THIS PRECIPITATION WAS OCCURRING WITHIN STRONG WARM CONVEYOR BELT...AND BENEATH PRONOUNCED DPVA... ASSOCIATED WITH A SHORT WAVE DISTURBANCE MOVING ACROSS THE PLAINS. SUB-FREEZING SURFACE-BASED AIR MASS BLANKETS ALL OF NERN IA AND SERN MN...WITH THE 32F ISOTHERM ROUGHLY RUNNING SOUTH TO NORTH ACROSS NCNTRL IA TO SCNTRL MN ATTM. A NARROW AXIS OF WARMER AND DRIER AIR ALOFT WAS OVERSPREADING PARTS OF IA AND SRN MN...JUST AHEAD OF THE DEVELOPING PRECIPITATION...BASED ON LATEST SHORT-TERM GUIDANCE AND 00Z RAOBS. NEAR FREEZING WET-BULB TEMPERATURES WITHIN THE ELEVATED DRY LAYER WILL LIKELY RESULT IN A TRANSITION TO ISOTHERMAL PROFILES COLD ENOUGH TO SUPPORT LIGHT SNOW AS PRECIPITATION PERSISTS ACROSS THE REGION LATER TONIGHT. HOWEVER...WITH THE ONSET OF EVAPORATIVE COOLING IN THIS WARM LAYER...THERE MAY BE ENOUGH POSITIVE AREA ALOFT TO SUPPORT A BRIEF PERIOD OF LIGHT FREEZING RAIN. HOURLY PRECIPITATION AMOUNTS OF 0.01-0.05 INCHES HAVE BEEN OCCURRING UPSTREAM. THESE LIGHT AMOUNTS FALLING AS FREEZING RAIN COULD MAKE ROADWAYS HAZARDOUS BEFORE PRECIPITATION CHANGES OVER TO LIGHT SNOW. ..CARBIN.. 12/14/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MPX...DMX...FSD... 42459400 43049459 43759487 44229483 44319429 43949361 43459327 42909311 42509306 42219309 42149351 WWWW From MCD at goshenarc.org Wed Dec 14 05:06:26 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 14 Dec 2005 00:06:26 -0500 Subject: [MCD] SWOMCD Message-ID: <200512140504.jBE54ZWJ029306@mail.goshen.edu> ACUS11 KWNS 140503 SWOMCD SPC MCD 140503 MNZ000-IAZ000-141000- MESOSCALE DISCUSSION 2554 NWS STORM PREDICTION CENTER NORMAN OK 1103 PM CST TUE DEC 13 2005 AREAS AFFECTED...NCNTRL IA...SCNTRL MN CONCERNING...HEAVY SNOW VALID 140503Z - 141000Z SNOWFALL RATES MAY APPROACH 1 INCH PER HOUR IN NORTH CENTRAL IOWA AND SOUTH CENTRAL MINNESOTA FROM 06Z/14 - 10Z/14. SURFACE OBSERVATIONS OVER THE PAST FEW HOURS HAVE INDICATED A TREND TOWARDS MODERATE SNOWFALL IN NORTH CENTRAL IOWA. A STRONG SHORTWAVE TROUGH LOCATED OVER EASTERN KANSAS AND EASTERN NEBRASKA IS PROVIDING AN AREA OF STRONG UPWARD VERTICAL MOTION OVER PORTIONS OF NORTH CENTRAL IOWA AND SOUTH CENTRAL MINNESOTA. 00Z NAM AND 00Z RUC BOTH AGREE THAT THIS AREA OF STRONG LIFT WILL STRENGTHEN FOR THE NEXT SEVERAL HOURS OVER THE REGION...AND GIVEN THE ABUNDANCE OF LOW-LEVEL MOISTURE...SOME AREAS MAY SEE SNOWFALL RATES INCREASE TO AT OR NEAR 1 INCH PER HOUR DURING THE TIME WHEN THE VERTICAL MOTION IS STRONGEST. THE AXIS OF GREATEST LIFT...AND HENCE HEAVY SNOW...WILL PIVOT TOWARDS THE NORTHEAST THROUGH THE NEXT SEVERAL HOURS BEFORE WEAKENING BY 12Z/14. ..LEVIT.. 12/14/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...DVN...ARX...MPX...DMX...FSD... 44899461 43949517 42899497 42089354 42299213 43709212 44789310 WWWW From MCD at goshenarc.org Wed Dec 14 12:44:37 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 14 Dec 2005 07:44:37 -0500 Subject: [MCD] SWOMCD Message-ID: <200512141242.jBECgo48000396@mail.goshen.edu> ACUS11 KWNS 141241 SWOMCD SPC MCD 141241 INZ000-KYZ000-MIZ000-ILZ000-WIZ000-141645- MESOSCALE DISCUSSION 2555 NWS STORM PREDICTION CENTER NORMAN OK 0641 AM CST WED DEC 14 2005 AREAS AFFECTED...PORTIONS ERN/NRN IL...SERN WI...SRN LM...SWRN LOWER MI...MOST OF INDIANA...SMALL PORTION N-CENTRAL KY. CONCERNING...HEAVY SNOW VALID 141241Z - 141645Z WITHIN BROAD NNW-SSE PLUME OF LIGHT-MDT SNOW...POCKETS OF HEAVIER RATES OF 1-1.5 INCHES/HOUR ARE EXPECTED THROUGH MID-LATE MORNING...AS BAND SHIFTS EWD ACROSS DISCUSSION AREA. SNOW SHOULD TRANSITION QUICKLY TO RAIN AT...OR SHORTLY AFTER...PASSAGE OF SFC FREEZING LINE...ALSO FROM SW-NE. MOISTURE CHANNEL IMAGERY AND VWP/PROFILER DATA AT 12Z INDICATED SHORTWAVE TROUGH FROM MSP AREA SEWD ACROSS SWRN IL. EXPECT THIS FEATURE TO DEAMPLIFY GRADUALLY AND EJECT ENEWD ACROSS WI/IL THROUGH REMAINDER MORNING...SUPPORTING PRECURSORY CORRIDOR OF MIDLEVEL DPVA AND STRONG/ELEVATED WAA PLUME IN LOW LEVELS. RELATED ASCENT OF DEEPLY SATURATED AND SUBFREEZING AIR MASS...WITH PW AROUND .5-.75 INCH BASED ON 12Z RAOBS AND INTERMEDIARY RUC SOUNDINGS...SHOULD SUPPORT EWD EXTENSION OF INTERMITTENT HEAVY SNOW NOW OBSERVED IN THIS REGIME. STRONGER DYNAMIC FORCING FARTHER N ACROSS NRN WI AND NWRN LOWER MI SHOULD BE OFFSET BY WEAKER MOISTURE TO LIMIT HEAVY SNOW THREAT...WHILE WARMING WITH TIME WILL RESTRICT SNOW POTENTIAL FARTHER S IN KY. OBSERVATIONAL DATA INDICATES QUICK TRANSITION FROM SNOW TO RAIN W OF SFC FREEZING LINE...A TREND EXPECTED TO CONTINUE THROUGH REMAINDER MORNING. HOWEVER...TIME SERIES OF RUC FCST SOUNDINGS SUGGESTS VERY BRIEF/LOCALIZED EPISODE OF FREEZING RAIN IS POSSIBLE INVOF 32 F ISOTHERM...AS WARMING ALOFT IN DENDRITIC CRYSTAL GROWTH LAYERS KEEPS PRECIP PARTICLES SUPERCOOLED. ANY FREEZING RAIN SHOULD BE SHORT-LIVED WITH RATES GENERALLY AROUND .10 INCH/HOUR OR LESS...AND REPLACED BY RAIN AT ANY GIVEN LOCATION WITHIN AN HOUR OR LESS. ..EDWARDS.. 12/14/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...ILN...LMK...IWX...GRR...IND...PAH...LOT...ILX...MKX... 38568734 39648867 41598911 42968777 42908661 41998603 39028519 37838594 WWWW From MCD at goshenarc.org Wed Dec 14 15:44:59 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 14 Dec 2005 10:44:59 -0500 Subject: [MCD] SWOMCD Message-ID: <200512141543.jBEFhA1C008077@mail.goshen.edu> ACUS11 KWNS 141542 SWOMCD SPC MCD 141542 LAZ000-TXZ000-141745- MESOSCALE DISCUSSION 2556 NWS STORM PREDICTION CENTER NORMAN OK 0942 AM CST WED DEC 14 2005 AREAS AFFECTED...SE TX...SW LA CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 141542Z - 141745Z CONVECTION WILL CONTINUE TO INCREASE ALONG THE UPPER TX COAST OVER THE NEXT FEW HOURS. A FEW OF THE STRONGER CELLS COULD PRODUCE MARGINALLY SEVERE HAIL. IF A SEVERE THREAT DEVELOPS...A WW MAY BECOME NECESSARY LATER THIS MORNING. AT THE SFC...A LOW-LEVEL MOISTURE AXIS EXTENDS NWD FROM JUST OFF THE LOWER TX COAST INTO THE VICTORIA AREA. NUMEROUS THUNDERSTORMS ARE CURRENTLY INCREASING IN INTENSITY ABOVE A WEAKLY CAPPED BOUNDARY LAYER EVIDENT ON THE 12Z SOUNDINGS SUGGESTING THE CONVECTION IS SLIGHTLY ELEVATED. AS AN UPPER-LEVEL TROUGH OVER WEST TX AND THE ASSOCIATED LIFT AHEAD OF THE TROUGH APPROACHES THE REGION LATE THIS MORNING...THE CAPPING INVERSION SHOULD CONTINUE TO WEAKEN ALLOWING CONVECTION TO EXPAND IN COVERAGE AND POSSIBLY ROOT NEARER THE SURFACE ACROSS SE TX INTO FAR SWRN LA. INITIAL ACTIVITY MAY PRODUCE MARGINALLY SEVERE HAIL. HOWEVER...AS THE STORMS BECOME ROOTED IN THE BOUNDARY LAYER...ISOLATED SEVERE THREAT WOULD INCREASE WITH DAMAGING WINDS/ISOLATED TORNADOES POSSIBLE IN THE STRONGER CELLS. ..BROYLES.. 12/14/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LCH...HGX...CRP...EWX... 27549622 27919727 28979756 30259586 30669367 30359193 29549137 28929212 28609344 28309458 WWWW From MCD at goshenarc.org Wed Dec 14 17:53:25 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 14 Dec 2005 12:53:25 -0500 Subject: [MCD] SWOMCD Message-ID: <200512141751.jBEHpaAT028711@mail.goshen.edu> ACUS11 KWNS 141750 SWOMCD SPC MCD 141750 LAZ000-MSZ000-TXZ000-141915- MESOSCALE DISCUSSION 2557 NWS STORM PREDICTION CENTER NORMAN OK 1150 AM CST WED DEC 14 2005 AREAS AFFECTED...FAR SE TX...SRN LA CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 141750Z - 141915Z CONVECTION CURRENTLY OVER SE TX WILL GRADUALLY SPREAD EWD INTO SRN LA OVER THE NEXT HOUR. THE STRONGER STORMS WILL HAVE THE POTENTIAL FOR BRIEF TORNADOES...HAIL AND ISOLATED DAMAGING WIND GUSTS. A WW MAY BE REQUIRED ACROSS THE REGION EARLY THIS AFTERNOON. SFC ANALYSIS CURRENTLY SHOWS ABUNDANT LOW-LEVEL MOISTURE IN PLACE ACROSS SE TX AND SW LA WITH SFC DEWPOINTS ABOVE 60 F EXTENDING EWD FROM THE HOUSTON AREA ACROSS MUCH OF SRN LA. OBJECTIVE ANALYSIS SHOWS A LOW-LEVEL JET AXIS IN PLACE ALONG THE TX COAST EXTENDING NWD INTO WRN LA. THIS FEATURE IS FORECAST BY THE NAM AND GFS SOLUTIONS TO SHIFT EWD THIS AFTERNOON AND INTENSIFY ACROSS SRN AND CNTRL LA. THIS WILL INCREASE LOW-LEVEL MOISTURE ACROSS SRN LA WITH SFC DEWPOINTS GRADUALLY INCREASING THROUGHOUT THE AFTERNOON. INCREASING INSTABILITY AND LARGE-SCALE ASCENT AHEAD OF AN APPROACHING UPPER-LEVEL TROUGH WILL CAUSE STORM COVERAGE TO EXPAND EWD. STRONG VERTICAL SHEAR ESPECIALLY IN THE LOW-LEVELS WILL BE FAVORABLE FOR ISOLATED SUPERCELLS WITH A THREAT FOR TORNADOES. IN ADDITION...HAIL AND A FEW DAMAGING WIND GUSTS WILL BE POSSIBLE WITH THE STRONGER STORMS. ..BROYLES.. 12/14/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...JAN...LIX...LCH...HGX... 30629434 31049369 31229185 31059124 30769096 30239079 29879090 29469124 29249261 29359394 29869441 WWWW From MCD at goshenarc.org Wed Dec 14 19:09:42 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 14 Dec 2005 14:09:42 -0500 Subject: [MCD] SWOMCD Message-ID: <200512141907.jBEJ7vte011672@mail.goshen.edu> ACUS11 KWNS 141905 SWOMCD SPC MCD 141904 LAZ000-TXZ000-142030- MESOSCALE DISCUSSION 2559 NWS STORM PREDICTION CENTER NORMAN OK 0104 PM CST WED DEC 14 2005 AREAS AFFECTED...UPPER TX COAST/FAR SERN TX INTO SWRN LA CONCERNING...TORNADO WATCH 894... VALID 141904Z - 142030Z CONTINUE VALID PORTIONS OF WW AS TORNADO THREAT WILL CONTINUE. BROKEN LINE OF INTENSE THUNDERSTORMS CONTINUES TO EVOLVE JUST WEST OF THE HOU METRO AREA ATTM. THIS ACTIVITY IS TRACKING EWD AT AROUND 35 KT AND SHOULD MOVE ACROSS GALVESTON BAY BY 20Z AND INTO FAR SWRN LA JUST AFTER 21Z IF IT MAINTAINS CURRENT FORWARD MOTION. VWP FROM HOU INDICATES EXTREME LOW LEVEL SHEAR WITH 0-1 KM SRH IN EXCESS OF 350 M2/S2...ALONG WITH 60+ KT OF SFC-6 KM SHEAR. PRIMARY CONCERN CONTINUES TO CENTER AROUND WEAK LOW LEVEL LAPSE RATES AND SUBSEQUENT MAINTENANCE OF SURFACE-BASED STORMS. MODIFIED HOURLY RUC SOUNDINGS INDICATE CONVECTION NEAR AND SOUTH-SOUTHWEST OF HOU IS VERY NEARLY SURFACE-BASED WITH SURFACE TEMPERATURES IN THE LOWER 70S AND DEW POINTS IN THE MID/UPPER 60S. IN ADDITION...STRONG SURFACE PRESSURE FALLS WILL ALSO ENHANCE LIFTING WITHIN THE BOUNDARY LAYER AND FURTHER INCREASE THE RISK OF INGESTING SURFACE-PARCELS. WITH SUCH EXTREME SHEAR...SUPERCELLS WILL CONTINUE TO SUPPORT A RISK OF TORNADOES GIVEN THE NEAR SURFACE-BASED NATURE OF THE STORMS. LARGE HAIL...DAMAGING WINDS AND VERY HEAVY RAINFALL RATES ARE ALSO EXPECTED. SLY LLJ IS FORECAST TO REMAIN ANCHORED INTO THE UPPER TX COAST THROUGH 21Z...SO FURTHER DEVELOPMENT WEST OF ONGOING STORMS MAY OCCUR NEAR THE SURFACE COLD FRONT INTO THE EARLY EVENING. HOWEVER...PRIMARY SEVERE THREAT SHOULD SHIFT INTO SWRN LA BETWEEN 21-00Z AS LLJ DEVELOPS INTO SWRN LA. AS DEW POINTS INCREASE INTO THE MID 60S AND LLJ DEVELOPS EWD...ADDITIONAL WATCH MAY BE NEEDED INTO SWRN LA PRIOR TO 20-21Z. ..EVANS.. 12/14/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LIX...LCH...HGX...CRP...EWX... 28029674 29819661 30879353 30859186 30189144 29439139 29169380 28019671  From MCD at goshenarc.org Wed Dec 14 23:59:16 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 14 Dec 2005 18:59:16 -0500 Subject: [MCD] SWOMCD Message-ID: <200512142357.jBENvR5H007310@mail.goshen.edu> ACUS11 KWNS 142356 SWOMCD SPC MCD 142356 LAZ000-150130- MESOSCALE DISCUSSION 2560 NWS STORM PREDICTION CENTER NORMAN OK 0556 PM CST WED DEC 14 2005 AREAS AFFECTED...SWRN / S-CNTRL LA CONCERNING...TORNADO WATCH 895... VALID 142356Z - 150130Z THROUGH 02Z...POTENTIAL FOR AN ISOLATED TORNADO WILL EXIST ACROSS ERN HALF OF WW AREA...MAINLY ALONG/S OF I-10. REGIONAL RADAR IMAGERY SHOWS THAT ONSHORE PORTION OF QUASI-LINEAR MCS HAS TENDED TO WEAKEN OVER THE PAST HOUR OR TWO WITH MOST INTENSE CONVECTION OBSERVED OFFSHORE SE OF LCH AS OF 2345Z. LATEST MESOANALYSIS INDICATES PRIMARY WARM FRONT FROM VICINITY OF ESF EWD TO S OF JAN...WITH A SECONDARY WARM FRONTAL FEATURE FARTHER TO THE S...EXTENDING FROM WEAK LOW PRESSURE ENE OF LCH SEWD TO N OF HUM. AIR MASS S OF THIS SECONDARY WARM FRONT IS COMPARATIVELY MORE MOIST WITH DEWPOINTS IN THE LOWER 60S...HOWEVER POOR LOW/MID-LEVEL LAPSE RATES ARE LARGELY INHIBITING DESTABILIZATION PROCESS. GIVEN STRONG SHEAR PROFILES OBSERVED ON LOCAL VWPS...THREAT OF AN ISOLATED TORNADO WILL EXIST WITH ANY CONVECTIVE ELEMENTS THAT CAN BECOME SUSTAINED ALONG/S OF THIS SECONDARY WARM FRONT. CURRENTLY...IT APPEARS THAT THE VERY MARGINAL INSTABILITY IS PRIMARY FACTOR LIMITING MORE SUBSTANTIAL ONSHORE DEVELOPMENT. ..MEAD.. 12/14/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LIX...LCH... 29359282 29929284 30519250 30669217 30669144 30079129 29469139 29119153 29119231 WWWW From MCD at goshenarc.org Thu Dec 15 01:14:25 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 14 Dec 2005 20:14:25 -0500 Subject: [MCD] SWOMCD Message-ID: <200512150112.jBF1Ccl0001182@mail.goshen.edu> ACUS11 KWNS 150111 SWOMCD SPC MCD 150111 MIZ000-WIZ000-150445- MESOSCALE DISCUSSION 2562 NWS STORM PREDICTION CENTER NORMAN OK 0711 PM CST WED DEC 14 2005 AREAS AFFECTED...NE WI AND PORTIONS OF UPPER MI CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION VALID 150111Z - 150445Z OCNLY MODERATE SNOW WILL SPREAD NEWD FROM FAR NE WI INTO CNTRL PORTIONS OF UPPER MI THIS EVENING. SNOW RATES WILL GENERALLY REMAIN BELOW 1 IN/HR. EAST OF STACKED UPPER CYCLONE CENTERED ALONG THE WRN MN/ERN DAKOTAS BORDER...LIGHT/OCNLY MDT SNOW FOCUSED EARLY THIS EVENING ACROSS ERN WI INTO MI EAST OF OCCLUDED FRONT. OBSERVATIONAL TRENDS SUGGESTS NEWD SPREAD OF ONGOING SNOWFALL FROM FAR NE WI INTO CNTRL UPPER MI THIS EVENING...ATTRIBUTABLE TO DPVA AND LOW/MID LEVEL ISENTROPIC ASCENT. 00Z GREEN BAY SOUNDING FEATURES 75MB WELL-SATURATED DENDRITIC GROWTH LAYER ABOVE 700MB...FAVORABLE FOR OCNLY MDT SNOW COUPLED WITH AMPLE UVVS. SNOW RATES SHOULD GENERALLY REMAIN BELOW 1 IN/HR...BUT LOCALIZED AREAS COULD EXCEED 1 IN/HR ACROSS THE SCNTRL PORTION OF UPPER MI...INCLUDING MENOMINEE AND DELTA COUNTIES WITH AID OF MOIST SELY TRAJECTORIES OFF LAKE MI. ..GUYER.. 12/15/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...APX...MQT...GRB... 46458604 46118584 45848634 45688661 45218705 44688750 44628799 45188891 45518895 45888884 46328806 WWWW From MCD at goshenarc.org Thu Dec 15 03:07:45 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 14 Dec 2005 22:07:45 -0500 Subject: [MCD] SWOMCD Message-ID: <200512150305.jBF35uRp011039@mail.goshen.edu> ACUS11 KWNS 150305 SWOMCD SPC MCD 150304 ALZ000-MSZ000-LAZ000-150430- MESOSCALE DISCUSSION 2563 NWS STORM PREDICTION CENTER NORMAN OK 0904 PM CST WED DEC 14 2005 AREAS AFFECTED...ERN LA INTO S-CNTRL AND SERN MS CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 150304Z - 150430Z THE THREAT OF ISOLATED DAMAGING WINDS AND PERHAPS A TORNADO APPEARS TO BE INCREASING AND CONVECTIVE TRENDS ARE BEING MONITORED FOR A POSSIBLE WW ISSUANCE. 00Z UPPER-AIR ANALYSIS INDICATES THAT INTENSE FORCING ASSOCIATED WITH A COUPLED UPPER JET STRUCTURE IS LIKELY AIDING IN INTENSIFICATION OF MCS OVER PORTIONS OF S-CNTRL MS INTO ERN LA OVER THE PAST HALF HOUR OR SO. CLOSE INSPECTION OF LOCAL RADAR DATA SHOWS A MESOSCALE CIRCULATION CENTER JUST SE OF MCB MOVING NEWD AT AROUND 50 KTS. ATTENDANT CONVECTIVE LINE FROM S OF JAN TO THIS MESOLOW AND THEN SWD TO N OF HUM HAS ALSO INTENSIFIED PER REFLECTIVITY AND LIGHTNING DATA. 00Z LIX OBSERVED AND PROXIMITY RUC FORECAST SOUNDINGS SUGGEST THAT THIS ACTIVITY IS LIKELY ELEVATED ABOVE A SURFACE STABLE LAYER WITH MUCAPES OF 100-400 J/KG. GIVEN DYNAMIC NATURE OF SYNOPTIC SYSTEM AND NEWD DEVELOPMENT OF PRIMARY SURFACE LOW INLAND ACROSS CNTRL MS OVERNIGHT...SOME CONCERN EXISTS THAT ENOUGH SURFACE-BASED INSTABILITY MAY DEVELOP AHEAD OF ONGOING CONVECTIVE LINE. AMBIENT SHEAR IS QUITE STRONG AND IF STORMS CAN BECOME ROOTED IN THE BOUNDARY-LAYER A THREAT FOR DAMAGING WINDS AND PERHAPS AN ISOLATED TORNADO WOULD INCREASE. ..MEAD.. 12/15/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MOB...JAN...LIX... 30299035 31329061 31749011 32178962 32038888 31408812 30548825 29688903 WWWW From MCD at goshenarc.org Thu Dec 15 03:47:06 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 14 Dec 2005 22:47:06 -0500 Subject: [MCD] SWOMCD Message-ID: <200512150345.jBF3jGFg029879@mail.goshen.edu> ACUS11 KWNS 150344 SWOMCD SPC MCD 150344 VAZ000-NCZ000-WVZ000-SCZ000-TNZ000-GAZ000-150945- MESOSCALE DISCUSSION 2564 NWS STORM PREDICTION CENTER NORMAN OK 0944 PM CST WED DEC 14 2005 AREAS AFFECTED...NRN GA / NWRN SC / WRN NC / WRN VA CONCERNING...FREEZING RAIN VALID 150344Z - 150945Z FREEZING RAIN WITH HOURLY RATES APPROACHING 0.10 TO 0.15 INCH IS EXPECTED TO DEVELOP ACROSS NRN GA/NWRN SC AND SPREAD NEWD ACROSS WRN PORTIONS OF NC AND VA BY 15/12Z. 00Z UPPER-AIR OBSERVATIONS INDICATE THAT FORCING ASSOCIATED WITH A COUPLED UPPER JET STRUCTURE AND LOW-LEVEL WAA ARE THE PRIMARY PROCESSES DRIVING LARGE PRECIPITATION SHIELD CURRENTLY OVER THE LOWER MS VALLEY INTO THE CNTRL GULF STATES AND TN VALLEY. ERN EDGE OF THIS PRECIPITATION SHIELD IS RAPIDLY EXPANDING NEWD ACROSS NRN GA WHERE SURFACE WET BULB TEMPERATURES ARE SUB-FREEZING. 00Z FFC SOUNDING SHOWS THAT LITTLE SATURATION IS NEEDED AROUND 850 MB TO SATURATE VERTICAL PROFILE AND GIVEN CURRENT OBSERVATIONS THIS HAS ALREADY OCCURRED. DEEP-LAYER FORCING FOR ASCENT...PRIMARILY FROM THE TWO AFOREMENTIONED PROCESSES...IS FORECAST TO DEVELOP ENEWD OVERNIGHT...SUSTAINING ONGOING PRECIPITATION SHIELD ACROSS THE CNTRL/SRN APPALACHIANS AND ADJACENT PIEDMONT REGION. STRONG LOW-LEVEL WAA ATOP SURFACE WEDGE FRONTAL ZONE IN IMMEDIATE LEE OF THE APPALACHIANS WILL RESULT IN A QUITE FAVORABLE VERTICAL THERMAL STRATIFICATION FOR FREEZING RAIN WITH A 3-4 C WARM NOSE DEVELOPING AROUND 850 MB. ..MEAD.. 12/15/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LWX...RAH...RNK...CAE...GSP...MRX...FFC... 34368457 35818251 36778111 37558040 38097928 37167871 35897945 34458154 33818322 33588420 WWWW From MCD at goshenarc.org Thu Dec 15 08:34:16 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 15 Dec 2005 03:34:16 -0500 Subject: [MCD] SWOMCD Message-ID: <200512150832.jBF8WSSZ020575@mail.goshen.edu> ACUS11 KWNS 150831 SWOMCD SPC MCD 150831 FLZ000-GAZ000-ALZ000-151030- MESOSCALE DISCUSSION 2565 NWS STORM PREDICTION CENTER NORMAN OK 0231 AM CST THU DEC 15 2005 AREAS AFFECTED...PORTIONS SRN AL...FL PANHANDLE CONCERNING...TORNADO WATCH 896... VALID 150831Z - 151030Z WW MAY BE CLEARED BEHIND PRIMARY SQUALL LINE MOVING EWD OVER WRN-MOST FL PANHANDLE AND ADJACENT MARINE ZONES OF FL/AL BORDER REGION. ALSO...PRIND WW MAY BE REMOVED OVER REMAINING SERN AL COUNTIES. RAIN-COOLED AIR MASS ACROSS SERN AL...WELL N OF MARINE FRONT IN GULF -- WILL NOT RECOVER ENOUGH TO ALLOW NEARLY SFC-BASED LIFTED PARCELS...BEFORE PRIMARY CONVERGENCE BAND PASSES. SFC COLD FRONT IS ANALYZED FROM NRN PORTION MS/AL BORDER SSWWD ACROSS MSY AREA AND INTO NWRN GULF. MAIN CONVECTIVE BAND PRECEDES COLD FRONT BY APPROXIMATELY 125 NM OVER GULF AND NNEWD INTO WRN-MOST FL PANHANDLE. MARINE/WARM FRONT IS ANALYZED NEAR BUOYS 42039 AND 42020...50-70 NM OFFSHORE AND DRIFTING NWD. BOW/LEWP FORMATIONS SHOULD CONTINUE TO DEVELOP ESPECIALLY OVER OFFSHORE WATERS OVER AND S OF MARINE FRONT. TORNADO AND SEVERE WIND POTENTIAL APPEARS TO BE DIMINISHING WITH EWD EXTENT AND WITH TIME BECAUSE OF 1. LOWER THETAE AND WEAKER BUOYANCY IN INFLOW LAYER INLAND AND 2. DECREASING PROBABILITY THAT MARINE FRONT AND ASSOCIATED BOUNDARY LAYER BUOYANCY WILL REACH LAND. INDEED...MODIFIED RUC SOUNDINGS INDICATE SBCAPE AND MLCAPE IS ENTIRELY OFFSHORE NOW. ADDITIONAL CONVECTION MAY DEVELOP ALONG/AHEAD OF SFC COLD FRONT BUT BEHIND INITIAL SQUALL LINE. SEVERE POTENTIAL WITH THIS ACTIVITY SHOULD BE TOO MINIMAL TO MAINTAIN WW BEHIND INITIAL CONVECTION. EXPECT RELATIVELY VEERED FLOW NEAR SFC AND ASSOCIATED REDUCTION OF LOW LEVEL SHEAR...COMBINED WITH REDUCED BUOYANCY IN POSTCONVECTIVE AIR MASS. ..EDWARDS.. 12/15/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...TAE...BMX...MOB... 29878505 29708592 29748733 29918733 31298709 31688534 31318501 30108503 WWWW From MCD at goshenarc.org Thu Dec 15 11:24:57 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 15 Dec 2005 06:24:57 -0500 Subject: [MCD] SWOMCD Message-ID: <200512151123.jBFBNA9A027231@mail.goshen.edu> ACUS11 KWNS 151122 SWOMCD SPC MCD 151122 FLZ000-151315- MESOSCALE DISCUSSION 2566 NWS STORM PREDICTION CENTER NORMAN OK 0522 AM CST THU DEC 15 2005 AREAS AFFECTED...PORTIONS WRN/CENTRAL FL PANHANDLE CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 151122Z - 151315Z NEW WW MAY BE REQUIRED ALONG COASTAL SECTIONS WRN/CENTRAL FL PANHANDLE. ORIGINAL MCS COLLAPSED WHILE MOVING INTO MORE STABLE AIR MASS...EXCEPT FOR SEVERAL CELLS ON ITS SRN END WHICH BROKE AWAY AND REMAIN RELATIVELY DISCRETE AS THEY MOVE NEWD TOWARD WALTON/BAY COUNTY COASTAL WATERS. ADDITIONAL ACTIVITY HAS DEVELOPED S OF AL COAST AND WRN FL PANHANDLE COAST...INVOF COMBINED OUTFLOW BOUNDARY AND MARINE/WARM FRONT...AND ALONG NNE-SSW ORIENTED COLD FRONTAL BAND EXTENDING SEAWARD FROM MOB BAY. SFC ANALYSIS INDICATES MARINE/WARM FRONT NOW ABOUT 40 NM OFFSHORE AL COAST AND WRN FL PANHANDLE...DRIFTING N. FRONT THEN EXTENDS SEWD INVOF BUOY 42036 IN NERN GULF. STRONG LOW LEVEL WAA AND SLY SFC FLOW COMPONENT MAY RESULT IN THIS FRONT -- AND ASSOCIATED NEAR-SFC BASED BUOYANCY -- REACHING COAST DURING NEXT 3-4 HOURS. AIR MASS S OF FRONT WILL BE FAVORABLY UNSTABLE WITH MLCAPES 500-1000 J/KG. VERTICAL SHEAR PROFILES SHOULD BE MAXIMIZED INVOF MARINE FRONT. ALONG THAT BOUNDARY...ELY FLOW COMPONENT -- STRENGTHENED AROUND S RIM OF PRESSURE GRADIENT ASSOCIATED WITH MCS OUTFLOW -- COMBINES WITH 850 MB WINDS THAT VEERED FOLLOWING INITIAL MCS TO YIELD ENLARGED LOW LEVEL HODOGRAPHS. MODIFIED VWP AND RUC SOUNDINGS SHOW 300-600 J/KG SRH IN 0-3 KM LAYER. ACCORDINGLY...SRM DATA INDICATES ROTATION IN SOME CELLS NEAR MARINE FRONT...AND ANY SFC-BASED STORM NEAR COAST WILL BEAR THREAT FOR TORNADOES. DAMAGING GUSTS ALSO MAY REACH SFC IN ANY LEWP/BOW FORMATIONS ASSOCIATED WITH DEVELOPING COLD FRONTAL CONVECTIVE LINE. ..EDWARDS.. 12/15/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...TAE...MOB... 29328472 29468586 29748733 29918733 30608702 30448575 30178487 29948447 WWWW From MCD at goshenarc.org Thu Dec 15 13:41:57 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 15 Dec 2005 08:41:57 -0500 Subject: [MCD] SWOMCD Message-ID: <200512151340.jBFDe9BB017861@mail.goshen.edu> ACUS11 KWNS 151337 SWOMCD SPC MCD 151337 GAZ000-FLZ000-151430- MESOSCALE DISCUSSION 2568 NWS STORM PREDICTION CENTER NORMAN OK 0737 AM CST THU DEC 15 2005 AREAS AFFECTED...PORTIONS FL PANHANDLE AND COASTAL BEND...SWRN GA. CONCERNING...TORNADO WATCH 897... VALID 151337Z - 151430Z SEVERE POTENTIAL REMAINS ALONG/AHEAD OF PRIMARY CONVECTIVE BAND...INDICATED AT 13Z FROM NRN WALTON COUNTY FL SSWWD ACROSS VPS AREA OVER OPEN GULF. SFC MESOANALYSIS INDICATES COMBINED MARINE/WARM FRONT AND OUTFLOW BOUNDARY FROM OLD MCS...NEAR LINE FROM 60 W PIE...15 S AAF...40 S VPS. TSTMS -- INCLUDING A FEW SUPERCELLS...HAVE DEVELOPED ALONG AND S OF THIS FRONT THEN WEAKENED AS THEY EITHER MOVE PROGRESSIVELY FARTHER N OF FRONTAL ZONE OR BECOME ABSORBED BY MAIN CONVECTIVE BAND. THIS TREND SHOULD CONTINUE FOR ANY ADDITIONAL ACTIVITY THAT DEVELOPS IN WARM SECTOR. HOWEVER...AS REGIME SHIFTS EWD TOWARD SEWD-ORIENTED COASTLINE THROUGH 15Z...TORNADO THREAT WILL INCREASE FROM PFN AREA SEWD TO VICINITY AAF WHERE WARM FRONT -- AND ASSOCIATED NEARLY SFC-BASED PARCELS -- IMPINGE ON COASTLINE. THEREAFTER...AIR MASS IS EXPECTED TO DESTABILIZE OVER TLH REGION AND FL COASTAL BEND...AS COMBINATION OF DIURNAL HEATING AND WAA RELATED TO VEERING SFC FLOW ACT TO BOOST SFC THETAE AND INTRODUCE AT LEAST MARGINAL SBCAPES 300-800 J/KG. SBCAPES APCHG 500 J/KG ALREADY ARE EVIDENT N OF WARM FRONT OVER NARROW AREA BETWEEN MAIN CONVECTIVE BAND AND PFN...WHERE 0-1 KM SRH 300-600 J/KG IS EVIDENT BASED ON MODIFIED TLH RAOB...VWP DATA AND RUC SOUNDINGS. ..EDWARDS.. 12/15/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...JAX...TAE... 29378319 29348520 30008652 30468633 30858609 31008484 30998289 30348319 WWWW From MCD at goshenarc.org Thu Dec 15 16:03:54 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 15 Dec 2005 11:03:54 -0500 Subject: [MCD] SWOMCD Message-ID: <200512151602.jBFG29g0000512@mail.goshen.edu> ACUS11 KWNS 151600 SWOMCD SPC MCD 151600 OHZ000-MIZ000-INZ000-152000- MESOSCALE DISCUSSION 2569 NWS STORM PREDICTION CENTER NORMAN OK 1000 AM CST THU DEC 15 2005 AREAS AFFECTED...NE INDIANA/SE MI/NW OH CONCERNING...HEAVY SNOW VALID 151600Z - 152000Z SNOW IS EXPECTED TO INCREASE THROUGH EARLY AFTERNOON FROM FAR NE INDIANA/NW OH INTO SE/THUMB OF MI. SNOW RATES WILL REACH 1 IN/HR ON A LOCALIZED BASIS. EAST OF STACKED LOW CENTERED ALONG THE MN/WI BORDER...OBSERVATIONAL TRENDS FEATURE AXIS OF INCREASING SNOW ACROSS NE INDIANA/WRN OH/FAR SE MI...PART OF BROADER BAROCLINIC LEAF STRUCTURE SEEN IN WATER VAPOR/INFRARED IMAGERY. THIS ACTIVITY IS FOCUSED IN GENERAL SSW-NNE ORIENTATION ALIGNED WITH MID LEVEL FRONTOGENETICAL FORCING BETWEEN 600-700 MB. SIMILAR TO OBSERVATIONAL TRENDS...09Z SREF AND LATEST RUC/WRF GUIDANCE SUGGESTS SNOW SHOULD CONTINUE TO INCREASE FROM FAR NE INDIANA/NW OH INTO SOUTHEAST/THUMB VICINITY OF MI THROUGH EARLY AFTERNOON. ALTHOUGH LOW LEVEL TEMPERATURES PROFILES ARE MARGINAL...AMPLE PRECIPITATION RATES SHOULD BE SUPPORTIVE OF MDT/OCNLY HEAVY WET SNOW. SNOW RATES MAY REACH 1 IN/HR ON A LOCALIZED BASIS INTO MID AFTERNOON. ..GUYER.. 12/15/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...CLE...ILN...DTX...APX...IWX...GRR...IND... 44538346 43738261 41298274 40408345 40298480 40818556 42338507 WWWW From MCD at goshenarc.org Thu Dec 15 17:08:37 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 15 Dec 2005 12:08:37 -0500 Subject: [MCD] SWOMCD Message-ID: <200512151706.jBFH6meg008785@mail.goshen.edu> ACUS11 KWNS 151705 SWOMCD SPC MCD 151705 GAZ000-FLZ000-151800- MESOSCALE DISCUSSION 2570 NWS STORM PREDICTION CENTER NORMAN OK 1105 AM CST THU DEC 15 2005 AREAS AFFECTED...ERN FL PANHANDLE AND FAR SWRN/SRN GA CONCERNING...TORNADO WATCH 897... VALID 151705Z - 151800Z PARAMETERS REMAIN FAVORABLE FOR TORNADOES ACROSS VALID PARTS OF WW 897 FROM THE ERN HALF OF FL PANHANDLE INTO FAR SWRN/SRN GA. GREATEST TORNADO THREAT SHOULD REMAIN ALONG/JUST INLAND OF THE FL COAST. 16Z SURFACE ANALYSIS CONTINUED TO SHOW A MESO-LOW OVER THE CENTRAL FL PANHANDLE AT THE INTERSECTION OF THE COLD FRONT/SQUALL LINE AND A WEDGE FRONT WHICH EXTENDED FROM THIS LOW ACROSS SRN GA TO JUST S OF SAV. A WARM FRONT EXTENDED FROM THE MESO-LOW SEWD JUST N OF AAF AND THEN OFFSHORE OVER THE NERN GULF. HIGHER THETA-E AIR MASS EXISTS S OF THIS WARM FRONT WITH SURFACE DEWPOINTS IN THE MID-UPPER 60S. REGIONAL RADARS INDICATED A BROKEN LINE OF DISCRETE STORMS EXTENDING FROM THE MESO-LOW SWD TO OFFSHORE OVER THE GULF. STRONGER ATTENDANT SHEAR COUPLETS WERE LOCATED WITH ACTIVITY AROUND THE AAF AREA AND SWD OFFSHORE. THESE STORMS WILL CONTINUE TO POSE THE GREATEST RISK FOR TORNADOES AS THIS ACTIVITY INGESTS THE RICHER BOUNDARY LAYER MOISTURE...WHERE 0-3 KM SRH VALUES EXCEED 600 M2/S2. 15Z RUC SUGGESTS THE WARM FRONT SHOULD MOVE INLAND ALONG TAYLOR COUNTY BY 18Z...INCREASING THE POTENTIAL FOR SURFACE BASED STORMS AND ATTENDANT TORNADO/DAMAGING WIND THREAT ACROSS THIS PART OF WW. LATEST TRENDS IN LIGHTNING DATA SUGGEST THE STRONGEST ACTIVITY IS ALONG AND OFFSHORE THE ERN FL PANHANDLE COAST. REGIONAL RADARS ALSO INDICATED A SIMILAR TREND FOR STORMS TO BE WEAKER AND/OR WEAKEN AS THEY MOVE NORTH OF THE WARM FRONT. ..PETERS.. 12/15/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...JAX...TAE... 29558514 31058493 31038262 29668353 29468504 WWWW From MCD at goshenarc.org Thu Dec 15 18:22:43 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 15 Dec 2005 13:22:43 -0500 Subject: [MCD] SWOMCD Message-ID: <200512151820.jBFIKsBm021871@mail.goshen.edu> ACUS11 KWNS 151820 SWOMCD SPC MCD 151819 GAZ000-FLZ000-151915- MESOSCALE DISCUSSION 2571 NWS STORM PREDICTION CENTER NORMAN OK 1219 PM CST THU DEC 15 2005 AREAS AFFECTED...ERN FL PANHANDLE AND FAR SRN GA CONCERNING...TORNADO WATCH 897... VALID 151819Z - 151915Z TORNADO/DAMAGING WIND THREATS EXPECTED TO CONTINUE THROUGH 19-21Z... PRIMARILY ALONG THE COASTAL AREAS OF VALID PART OF WW 897. THUS...ERN PARTS OF WW /TAYLOR...LAFAYETTE AND DIXIE COUNTIES/ MAY NEED TO BE LOCALLY EXTENDED FOR 1-2 HOURS. REGIONAL RADARS/LIGHTNING DATA INDICATED STRONGEST ACTIVITY WAS LOCATED FROM SE OF TLH OVER ERN LEON/WAKULLA COUNTIES AND SWD OFFSHORE OVER THE NERN GULF OF MEXICO. STRONG SHEAR COUPLETS WERE ASSOCIATED WITH OFFSHORE DISCRETE STORMS EXTENDING FROM 50 E AAF TO 60 SSE AAF. AIR MASS DOWNSTREAM OVER THE FL BIG BEND REGION HAS BEEN SLOWLY MODIFYING WITH SURFACE DEWPOINTS INTO THE MID-UPPER 50S. CLOUDINESS ASSOCIATED WITH BROKEN LINE OF STORMS SPREADING DOWNSTREAM ACROSS ERN PARTS OF WW 897 AND THE REST OF NRN FL/SRN GA IS LIMITING OVERALL SURFACE HEATING/DESTABILIZATION. THUS...GIVEN MORE STABLE AIR MASS INLAND OVER NRN FL...NEW WW IS NOT WARRANTED. HOWEVER...SERN PART OF WW MAY NEED TO BE LOCALLY EXTENDED AS STRONGER OFFSHORE STORMS POSE A THREAT TO THESE COUNTIES BETWEEN 19-21Z. ..PETERS.. 12/15/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...TBW...JAX...TAE... 29458482 29918453 31028410 31038258 29378297 29038348 WWWW From MCD at goshenarc.org Thu Dec 15 18:45:52 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 15 Dec 2005 13:45:52 -0500 Subject: [MCD] SWOMCD Message-ID: <200512151844.jBFIi42b004268@mail.goshen.edu> ACUS11 KWNS 151843 SWOMCD SPC MCD 151843 PAZ000-MDZ000-NYZ000-VAZ000-WVZ000-NCZ000-OHZ000-TNZ000-152345- MESOSCALE DISCUSSION 2572 NWS STORM PREDICTION CENTER NORMAN OK 1243 PM CST THU DEC 15 2005 AREAS AFFECTED...MUCH OF PA/FAR SRN NY/WRN AND CNTRL MD/ERN WV/WRN VA/WRN NC CONCERNING...WINTER MIXED PRECIPITATION VALID 151843Z - 152345Z PREDOMINANT FREEZING RAIN/SLEET IS EXPECTED THIS AFTERNOON FROM FAR NE OH INTO WRN/SCNTRL PA AND WRN/CNTRL MD. PRECIPITATION RATES SHOULD INCREASE ACROSS CNTRL/ERN PA THROUGH 21Z-0ZZ...WITH SNOW PREDOMINANT PRECIP TYPE. FURTHER SOUTH...FREEZING RAIN WILL CONTINUE FOR THE NEXT SEVERAL HOURS ALONG THE SPINE OF THE CNTRL APPALACHIANS...WITH A GRADUAL CHANGE OVER TO ALL RAIN OCCURRING FROM SOUTH TO NORTH THIS AFTERNOON. EXTENSIVE PRECIPITATION SHIELD WILL CONTINUE TO SPREAD E/NE FROM THE OHIO VALLEY/MID ATLANTIC INTO THE NE STATES THIS AFTERNOON...ATTRIBUTABLE TO AMPLE UVVS VIA JUXTAPOSITION OF DPVA/UPPER JET ENHANCED LIFT AND LOW LEVEL WAA/MOISTURE TRANSPORT REGIME. IN ACCORDANCE WITH OBSERVATIONAL TRENDS...15Z RUC SOUNDINGS AND 09Z SREF CONSENSUS/WINTER ALGORITHMS SUGGEST RELATIVELY LONGEST DURATION/GREATEST PROBABILITY FOR FREEZING RAIN AND/OR SLEET THROUGH 21Z-00Z SHOULD OCCUR ACROSS WRN/SCNTRL PA...WRN/CNTRL MD...AND ERN WV/NW VA. IN THESE AREAS...ENCROACHING 800-850 MB LEVEL WARM LAYER /AS SAMPLED BY 12Z ROANOKE RAOB/ WILL BE FAVORABLE FOR FREEZING RAIN AND/OR SLEET WHERE SUB-FREEZING NEAR-SFC TEMPS ARE MAINTAINED...WHICH IS ESPECIALLY LIKELY IN VALLEY AREAS. WITH SOUTHWARD EXTENT...OWING TO STRONG WARM AIR ADVECTION REGIME...INITIAL COLD WEDGE WILL GRADUALLY BE OVERCOME ALONG/EAST OF THE CNTRL APPALACHIANS THROUGH THE AFTERNOON. PREDOMINANT PRECIP-TYPE IS EXPECTED TO GRADUALLY CHANGE FROM FREEZING RAIN TO RAIN ACCORDINGLY FROM SOUTH TO NORTH ACROSS THE NW NC/VA APPALACHIANS. ..GUYER.. 12/15/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...PHI...BGM...BUF...CTP...LWX...RNK...PBZ...RLX...CLE...GSP...MRX... 39847594 38947734 36697977 35838135 36068174 36598178 37628113 38897964 40268013 41098099 41888047 42387805 41237558 WWWW From MCD at goshenarc.org Thu Dec 15 19:26:14 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 15 Dec 2005 14:26:14 -0500 Subject: [MCD] SWOMCD Message-ID: <200512151924.jBFJORBP029808@mail.goshen.edu> ACUS11 KWNS 151923 SWOMCD SPC MCD 151923 MIZ000-152300- MESOSCALE DISCUSSION 2573 NWS STORM PREDICTION CENTER NORMAN OK 0123 PM CST THU DEC 15 2005 AREAS AFFECTED...NE LOWER MI CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION VALID 151923Z - 152300Z OCNLY MODERATE SNOW WILL DEVELOP/SPREAD FROM THE THUMB AREA INTO NE LOWER MI THROUGH MID AFTERNOON. RATES COULD REACH 1 IN/HR WITHIN THE HEAVIER BANDS FOR A FEW HOURS DURATION BETWEEN 20Z-00Z. VOLUMETRIC RADAR TRENDS SUGGESTS AREAS OF MODERATE SNOW...ONGOING EARLY THIS AFTERNOON ACROSS SE LOWER MI...SHOULD CONTINUE TO SPREAD N/NE INTO THE NE PORTION OF LOWER MI REMAINDER OF THE AFTERNOON. SIMILAR TO OBSERVATIONAL TRENDS...SHORT-TERM RUC/4KM WRF GUIDANCE SUGGESTS THIS WILL GENERALLY OCCUR IN AREAS ALONG/EAST OF INTERSTATE 75. ATTRIBUTABLE TO AMPLE UVVS/SATURATED FAVORABLE DENDRITIC GROWTH ZONE PER 18Z RUC SOUNDINGS...SNOW RATES COULD LOCALLY REACH 1 IN/HR FOR A COUPLE HOURS DURATION. ..GUYER.. 12/15/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...DTX...APX... 45528411 45258321 44588303 43998290 43488319 43498410 43758437 44668453 WWWW From MCD at goshenarc.org Thu Dec 15 22:49:41 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 15 Dec 2005 17:49:41 -0500 Subject: [MCD] SWOMCD Message-ID: <200512152247.jBFMlvMi017004@mail.goshen.edu> ACUS11 KWNS 152247 SWOMCD SPC MCD 152246 FLZ000-160015- MESOSCALE DISCUSSION 2574 NWS STORM PREDICTION CENTER NORMAN OK 0446 PM CST THU DEC 15 2005 AREAS AFFECTED...WRN FL PENINSULA CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 152246Z - 160015Z POTENTIAL FOR AN ISOLATED TORNADO OR LOCALLY STRONG WINDS WILL EXIST ACROSS DISCUSSION AREA THIS EVENING. OVERALL SEVERE THREAT APPEARS QUITE LIMITED AND A WW IS NOT ANTICIPATED. AS OF 2235Z...TAMPA RADAR INDICATED A PRE-FRONTAL BAND OF TSTMS OFF THE WRN FL PENINSULA WITH THE MOST INTENSE ACTIVITY FROM 45 NW OF PIE TO 60 W PIE. LOCAL AIR MASS ALONG THE COAST IS MOIST AND MODERATELY UNSTABLE WITH MUCAPES OF AROUND 1000 J/KG. ADDITIONALLY...AMBIENT SHEAR PROFILES REMAIN SUPPORTIVE OF ORGANIZED STORMS /SUPERCELLS/ WITH EFFECTIVE BULK SHEARS OF 35-40 KTS AND 0-1 KM SRH OF 200-250 M2/S2. POTENTIAL FOR AN ISOLATED TORNADO OR LOCALLY DAMAGING WIND GUST WILL EXIST WITH THE MOST INTENSE STORMS AS THEY APPROACH THE COAST. HOWEVER...IT APPEARS THAT THE ABSENCE OF ANY APPRECIABLE LARGE-SCALE FORCING AND DEEP FRONTAL CONVERGENCE SHOULD TEND TO LIMIT THE OVERALL SEVERE WEATHER THREAT...ESPECIALLY AS THE BOUNDARY-LAYER COOLS LATER THIS EVENING. ..MEAD.. 12/15/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...TBW...JAX... 29008292 29378266 29388221 28708209 28268225 28048264 28288295 WWWW From MCD at goshenarc.org Fri Dec 16 01:21:24 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 15 Dec 2005 20:21:24 -0500 Subject: [MCD] SWOMCD Message-ID: <200512160119.jBG1Jb6u012833@mail.goshen.edu> ACUS11 KWNS 160118 SWOMCD SPC MCD 160118 CTZ000-MAZ000-NYZ000-NJZ000-PAZ000-MDZ000-VAZ000-WVZ000-160545- MESOSCALE DISCUSSION 2575 NWS STORM PREDICTION CENTER NORMAN OK 0718 PM CST THU DEC 15 2005 AREAS AFFECTED...SRN AND CNTRL NY/MUCH OF PA/WRN CT/NRN NJ/MD/FAR NRN VA/WV PANHANDLE CONCERNING...WINTER MIXED PRECIPITATION VALID 160118Z - 160545Z PRIMARILY FREEZING RAIN...WITH POTENTIAL FOR ICE ACCUMULATIONS...WILL CONTINUE TO TRANSITION NEWD ACROSS CNTRL/ERN PA...NRN NJ...INTO SRN/CNTRL NY AND WRN CT THIS EVENING. ACROSS WRN PA/WRN NY...A CHANGE OVER TO ALL SNOW IS EXPECTED THIS EVENING...WITH MDT/LOCALLY HEAVY SNOW DEVELOPING BY LATE EVENING/OVERNIGHT. FURTHER SOUTH...INITIAL FREEZING RAIN SHOULD CHANGE OVER TO RAIN ACROSS NRN VA/MUCH OF MD/SE PA/MOST OF NJ PRIOR TO 06Z. WITH BROAD NEGATIVE TILT TROUGH CENTERED OVER THE UPPER MISSISSIPPI VALLEY...VORTICITY MAX AND STRONG MID/UPPER JET CONTINUES TO RACE EWD TOWARD THE MID ATLANTIC/NORTHEAST STATES WITHIN BASE OF UPPER TROUGH. ACCORDINGLY...BROAD/DEEP FORCING FOR ASCENT IS CONTRIBUTING TO NEWD TRANSITION OF BROAD PRECIPITATION SHIELD INTO THE NORTHEAST STATES. AS SEEN IN THE 00Z WASHINGTON-DULLES RAOB...NWD EXTRAPOLATION OF ELEVATED MELTING LAYER WILL REMAIN SUPPORTIVE OF FREEZING RAIN AS PRIMARY PRECIP-TYPE ACROSS MUCH OF CNTRL/ERN PA AND NRN NJ INTO SRN/CNTRL NY AND WRN CT MUCH OF THE EVENING...WHERE WEDGE OF SHALLOW COLD AIR WILL BE MAINTAINED. SOME SLEET/SNOW WILL BE POSSIBLE AS WELL. FURTHER WEST...00Z PITTSBURG AND 00Z BUFFALO RAOBS FEATURE A 1-2C WARM LAYER NEAR 850 MB...STILL AT LEAST MARGINALLY SUPPORTIVE OF FREEZING RAIN/SOME SLEET. HOWEVER...WITH NOCTURNAL/DYNAMIC COOLING AND EVENTUAL COLD ADVECTION...21Z RUC GUIDANCE SUGGESTS A GRADUAL CHANGE OVER TO ALL SNOW SHOULD OCCUR ACROSS MUCH OF WRN PA/WRN NY BY LATE EVENING...WITH MDT/LOCALLY HEAVY SNOW PREVALENT INTO THE OVERNIGHT. SNOW RATES MAY REACH 1 IN/HR IN THESE AREAS BY 06Z. ..GUYER.. 12/16/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...BOX...OKX...ALY...PHI...BGM...BUF...CTP...LWX...PBZ...RLX...CLE... 43007437 41607284 41177380 40127503 39637663 39227774 38567885 38737931 39677952 40097994 41568027 43177865 43397632 WWWW From MCD at goshenarc.org Fri Dec 16 06:51:04 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Fri, 16 Dec 2005 01:51:04 -0500 Subject: [MCD] SWOMCD Message-ID: <200512160649.jBG6nK1N028718@mail.goshen.edu> ACUS11 KWNS 160648 SWOMCD SPC MCD 160647 MEZ000-MAZ000-NHZ000-RIZ000-VTZ000-CTZ000-NYZ000-NJZ000-PAZ000-161215- MESOSCALE DISCUSSION 2576 NWS STORM PREDICTION CENTER NORMAN OK 1247 AM CST FRI DEC 16 2005 AREAS AFFECTED...MUCH OF NEW ENGLAND/NRN APPALACHIANS CONCERNING...WINTER MIXED PRECIPITATION VALID 160647Z - 161215Z A MIX OF FREEZING RAIN/SLEET AND SNOW WILL DEVELOP ACROSS MUCH OF NEW ENGLAND OVERNIGHT. FREEZING RAIN WILL CHANGEOVER TO MODERATE TO HEAVY SNOW /HRLY RATES UP TO 1 INCH/ ACROSS PORTIONS OF CENTRAL/NRN PA INTO WRN/NRN NY...WITH FREEZING RAIN CHANGING OVER TO RAIN OVER FAR NRN NJ/NERN PA...THE LOWER HUDSON RIVER VALLEY AND MUCH OF CT THROUGH 12Z. HOURLY FREEING RAIN/SLEET RATES AROUND 0.10 INCH WILL BE COMMON ACROSS PORTIONS OF THE MIDDLE HUDSON RIVER VALLEY OF ECENTRAL NY AND WRN PORTIONS OF MA/FAR SRN VT/SRN NH...LEADING TO THE POTENTIAL FOR SIGNIFICANT SLEET AND ICING IN THESE AREAS THROUGH 12Z. STRONG LOW LEVEL WAA WILL CONTINUE IN ADVANCE OF POTENT UPPER TROUGH MOVING THROUGH THE OHIO VALLEY. AT THE SURFACE...THE TREND OF A SLOWLY LIFTING SURFACE 32 DEG F LINE WILL CONTINUE OVERNIGHT AS A SURFACE LOW PRESSURE CENTERED OVER NEAR BWI AT 05Z LIFTS TOWARDS NYC BY 12Z. THEREFORE...NRN NJ...NERN PA...THE LOWER HUDSON RIVER VALLEY AND MUCH OF CT WILL SEE A CHANGEOVER FROM FREEZING PRECIP TO RAIN THROUGH 12Z. FURTHER NORTH...THE STRENGTH OF THE WAA AND GRADUAL SHRINKING OF THE ELEVATED WARM LAYER DEPTH DUE TO ASCENT WILL SUPPORT A MIX OF MODERATE TO OCCASIONALLY HEAVY FREEZING RAIN AND SLEET ACROSS MUCH OF ECENTRAL/NERN NY...VT/NH AND MA THROUGH 12Z. FURTHER WEST...LOW LEVEL CAA WAS COMMENCING PER VWP DATA AT PBZ. IN ADDITION...MID LEVEL FRONTOGENESIS WILL CONTINUE TO INTENSIFY IN THE 700-600 MB LAYER SUPPORTING DENDRITIC SNOW GROWTH. THESE TWO WILL COMBINE TO AID IN A CHANGEOVER OF P-TYPE FROM FREEZING RAIN TO MOD-HVY SNOW OVER NCENTRAL PA NWD INTO WRN/NRN NY...ESPECIALLY DURING THE 08-12Z TIME FRAME. ..CROSBIE.. 12/16/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...GYX...BOX...BTV...OKX...ALY...PHI...BGM...BUF...CTP...PBZ... 44387148 43317068 42237116 41737201 41157332 41117459 41077533 40937637 40587783 41147903 43077776 44837533 44907298 WWWW From MCD at goshenarc.org Fri Dec 16 11:57:35 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Fri, 16 Dec 2005 06:57:35 -0500 Subject: [MCD] SWOMCD Message-ID: <200512161155.jBGBtoe6014561@mail.goshen.edu> ACUS11 KWNS 161155 SWOMCD SPC MCD 161154 MEZ000-MAZ000-NHZ000-VTZ000-NYZ000-161700- MESOSCALE DISCUSSION 2577 NWS STORM PREDICTION CENTER NORMAN OK 0554 AM CST FRI DEC 16 2005 AREAS AFFECTED...NERN NY...VT...NH...ME...NWRN MA CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION VALID 161154Z - 161700Z ...WINTER STORM PRODUCING AREAS OF ICE AND SNOW ACROSS THE NORTHEAST... FZRA WILL CREATE HAZARDOUS ICING FROM PARTS OF ERN NY... MA...SRN VT/NH...AND SWRN ME THIS MORNING. MDT TO HVY SN WILL FALL FROM CNTRL/NERN NY...AND ALONG THE CANADIAN BORDER FROM VT/NH TO INTERIOR MAINE. A BROAD TRANSITION ZONE OF SN...PL...AND FZRA WILL CONTINUE FROM CNTRL VT/NH TO MAINE THIS MORNING BEFORE CHANGING BACK TO SN BY AFTERNOON. AN INTENSE AND FAST-MOVING MID/UPPER LEVEL IMPULSE WAS ROTATING THROUGH THE ERN PERIPHERY OF A LARGE CLOSED LOW OVER WI THIS MORNING. DPVA ASSOCIATED WITH THE IMPULSE/JET HAS INDUCED SURFACE CYCLOGENESIS ALONG COASTAL BAROCLINIC ZONE VICINITY OF NJ. VERY TIGHT PRESSURE GRADIENT BETWEEN THE DEEPENING SECONDARY LOW AND A STRONG SURFACE HIGH OVER SRN QUEBEC WAS CONTRIBUTING TO PRONOUNCED INFLUX OF ATLANTIC MOISTURE NWWD AND INLAND ATOP SURFACE-BASED COLD DOME FROM ERN NY ACROSS NRN NEW ENGLAND. MID/UPPER LEVEL DRYING WAS DEVELOPING NEWD ACROSS VT/NH EARLY THIS MORNING BASED ON RECENT SATELLITE AND RADAR TRENDS. THIS WILL RESULT IN LOWER PCPN RATES IN THE SHORT TERM ACROSS THESE AREAS. WRF AND ENSEMBLE MEAN QPF WERE INDICATING ONE PCPN MAX ASSOCIATED WITH LIFT NEAR THE SURFACE LOW/BAROCLINIC ZONE...AND ANOTHER PCPN MAX FROM NERN NY TO SRN QUEBEC. AREAS IN THE SRN ZONE OF HEAVIER PCPN... FROM SERN NY ACROSS MA AND INTO SRN NH AND MAINE...MAY EXPERIENCE A PERIOD OF HVY ICING THIS MORNING AS WARMER AIR ALOFT CONTINUES TO SPREAD INLAND OVER THE SUB-FREEZING AIR AT THE SURFACE. SN WILL CHANGE TO A PERIOD OF FZRA IN THESE AREAS. THIS HAS ALREADY HAPPENED OVER SWRN MA...AND IS EXPECTED TO DEVELOP NEWD ACROSS SRN NH AND ME OVER THE NEXT FEW HOURS. FARTHER NORTH...SECONDARY PCPN MAXIMUM...FROM NERN NY ACROSS SRN QUEBEC...NRN VT/NH...AND INTERIOR ME...WILL LIKELY BE PRIMARILY IN THE FORM OF SN. INTENSE QG FORCING FOR ASCENT WILL CONTINUE TO PIVOT ENEWD FROM CNTRL/NERN NY THIS MORNING...AND ACROSS NRN NEW ENGLAND TO INTERIOR ME THROUGH THIS AFTERNOON. DYNAMIC COOLING IN THE LOW TO MID LEVELS WILL OFFSET WARM ADVECTION AND...COUPLED WITH INFLUX OF MOISTURE INTO THIS REGION...SUPPORT MDT TO HVY SN ON THE NRN EDGE OF THE PCPN TRANSITION ZONE. SN WILL TAPER OFF AND END FROM WEST TO EAST AS THE STRONGER UPPER FORCING MOVES ACROSS THESE AREAS THROUGH THE DAY. ..CARBIN.. 12/16/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...CAR...GYX...BOX...BTV...ALY...BGM...BUF... 46297016 45717074 45447138 45327257 45147396 44837539 44267584 43177599 42847534 42817408 42127365 42057269 42447120 42887082 43477058 44136923 45856858 46386920 WWWW From MCD at goshenarc.org Fri Dec 16 18:48:50 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Fri, 16 Dec 2005 13:48:50 -0500 Subject: [MCD] SWOMCD Message-ID: <200512161847.jBGIl7IR005955@mail.goshen.edu> ACUS11 KWNS 161846 SWOMCD SPC MCD 161845 MEZ000-NHZ000-VTZ000-162245- MESOSCALE DISCUSSION 2578 NWS STORM PREDICTION CENTER NORMAN OK 1245 PM CST FRI DEC 16 2005 AREAS AFFECTED...NRN VT/NH/MUCH OF ME CONCERNING...HEAVY SNOW VALID 161845Z - 162245Z ...SNOW WILL BE INCREASING IN INTENSITY ACROSS MUCH OF ME THIS AFTN...WITH RATES OF 1 TO 2 INCHES PER HOUR. MODERATE TO HEAVY SNOW WILL BE DIMINISHING ACROSS VT/NH WITHIN 1-3 HOURS... LATEST SFC ANALYSIS SHOWS RAPIDLY FALLING SFC PRESSURE /2-3MB PER HOUR OFFSHORE/ WITH LOW NOW NEAR BEDFORD. SYSTEM IS QUICKLY LIFTING NORTHEAST WITH DRIER AIR APPROACHING FROM THE SW PER WV LOOPS. COMPOSITE RADAR IMAGERY DEPICTS ENHANCED REFLECTIVITY RETURNS ACROSS SRN ME NEAR PORTLAND. RECENT SFC OBSERVATIONS AT KDAW /DAWSON/ INDICATED HEAVY RAIN...WITH HEAVY SNOW NOW AT KIZG /FRYEBERG/...AS THIS MORE INTENSE PRECIPITATION MOVES BY. THERMAL PROFILES SUPPORT ALL SNOW...EXCEPT NEAR THE COASTAL AREAS WHERE RAIN WILL OCCUR. SNOW RATES WILL BE ENHANCED BOTH BY STRONG FRONTOGENESIS THROUGH A DEEP LAYER AND A SATURATED DENDRITIC ZONE...WHICH FORECAST SOUNDINGS SUGGEST WILL BE MAINTAINED TIL AT LEAST 21Z AROUND KBGR AND THROUGH 00Z NEAR KCAR. HEAVY SNOW NOW ONGOING ACROSS NRN PORTIONS OF VT/NH WILL END WITHIN A COUPLE HOURS. BUT IT APPEARS MODERATE TO HEAVY SNOW WILL CONTINUE ACROSS MUCH OF ME THROUGH THE AFTN. ..TAYLOR.. 12/16/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...CAR...GYX...BOX...BTV... 46537078 47446915 47086764 46066784 44886871 43067142 43337229 44167251 44997261 WWWW From MCD at goshenarc.org Sun Dec 18 08:17:32 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sun, 18 Dec 2005 03:17:32 -0500 Subject: [MCD] SWOMCD Message-ID: <200512180815.jBI8FqGn015072@mail.goshen.edu> ACUS11 KWNS 180814 SWOMCD SPC MCD 180814 CAZ000-181415- MESOSCALE DISCUSSION 2579 NWS STORM PREDICTION CENTER NORMAN OK 0214 AM CST SUN DEC 18 2005 AREAS AFFECTED...CA SIERRA NEVADA MOUNTAINS CONCERNING...HEAVY SNOW VALID 180814Z - 181415Z HEAVY WET SNOW IS EXPECTED TO OVERSPREAD THE SIERRA RANGE IN THE NEXT SEVERAL HOURS AS MOIST PACIFIC STORM SYSTEM MOVES INLAND. SNOWFALL RATES AOA 6000 FEET COULD EXCEED 2 INCHES PER HOUR THIS MORNING. OVER THE NEXT SEVERAL HOURS...PRECIPITATION RATES WILL CONTINUE TO INCREASE AND SPREAD INLAND FROM THE COAST AND ACROSS THE CNTRL VALLEY OF CA AS POTENT PACIFIC PERTURBATION MOVES EAST ACROSS THE NCNTRL CA COAST. OBSERVED RAINFALL RATES NEAR THE COAST WERE ALREADY IN THE RANGE OF 0.10 TO 0.25 INCHES PER HOUR WITHIN WARM AIR ADVECTION REGIME AHEAD OF THE STRONGER DYNAMIC FORCING. /REF NFDSPENES WMO HEADER TXUS20/. INTENSIFYING UPSLOPE FLOW AND DYNAMIC FORCING WITH THE MID/UPPER LEVEL IMPULSE/WIND MAX...ALONG WITH ENHANCED MOISTURE TRANSPORT ACCOMPANYING +1 INCH PW PLUME...WILL LEAD TO EXCESSIVE SNOWFALL RATES DEVELOPING ACROSS THE HIGHER ELEVATIONS THROUGH 12Z. WHILE SNOW LEVELS MAY INITIALLY CLIMB ABOVE 6000 FEET...FREEZING LEVELS WILL BEGIN TO FALL LATER THIS MORNING AS ADIABATIC COOLING WITHIN THE UPPER TROUGH AXIS SPREADS ACROSS THE AREA. WITH POTENTIAL FOR EMBEDDED CONVECTION...AND DECENT AGREEMENT IN LATEST SHORT-TERM QPF GUIDANCE FROM NAM AND RUC MODELS...SNOWFALL RATES OF 2-4 INCHES PER HOUR APPEAR LIKELY NEAR AND SOUTH OF THE TAHOE AREA BEFORE 12Z. WINDS ALSO INCREASING TO NEAR 50KT LATER THIS MORNING WILL PRODUCE DRIFTING SNOW AND WHITE-OUT CONDITIONS. ..CARBIN.. 12/18/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...VEF...REV...HNX...STO... 37021850 36771865 37371945 37972000 38232022 38682029 39242058 39532070 39762078 40232140 40502156 40502133 40442108 40292076 40112059 39902037 39672017 38932008 37431870 WWWW From MCD at goshenarc.org Sun Dec 18 18:57:33 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sun, 18 Dec 2005 13:57:33 -0500 Subject: [MCD] SWOMCD Message-ID: <200512181855.jBIItsto029089@mail.goshen.edu> ACUS11 KWNS 181855 SWOMCD SPC MCD 181855 NVZ000-IDZ000-ORZ000-CAZ000-190100- MESOSCALE DISCUSSION 2580 NWS STORM PREDICTION CENTER NORMAN OK 1255 PM CST SUN DEC 18 2005 AREAS AFFECTED...CNTRL AND ERN ORE/SIERRA/NRN NV CONCERNING...HEAVY SNOW VALID 181855Z - 190100Z ...MODERATE TO HEAVY SNOW WILL CONTINUE ACROSS THE NRN GREAT BASIN THROUGH AFTN...WITH SNOW SPREADING INTO THE ERN SLOPES OF THE CASCADES WITHIN A FEW HOURS. SNOW RATES ABOVE 4000 FEET MAY BE IN THE 2-3 INCH PER HOUR RANGE... LATEST IR SATELLITE IMAGERY SHOWS INCREASING MOISTURE/CLOUDS MOVING ACROSS SRN ID/ORE WITH SOME COOLING CLOUD TOPS NOTED. ENHANCED BAND OF CLOUDS SEEMS TO BE ASSOCIATED WITH DEFORMATION BAND NEAR 700MB. HEAVIEST SNOW CURRENTLY OVER NRN PORTIONS OF NV FROM LOL/WMC/EKO. MEANWHILE...SNOW HAS CHANGED OVER TO RAIN IN THE TAHOE/RENO AREA...SUGGESTING FROM THE SFC OBSERVATIONS THAT THE FREEZING LEVEL HAS RISEN ABOVE 6000 FEET. BAND OF SNOW IS EXPECTED TO INCREASE FROM DESCHUTES CO ORE INTO SW ID AND NW UT...ASSOCIATED WITH FRONTOGENETIC FORCING WITHIN THE 750-650 MB LAYER AND UPWARD MOTION DUE TO VORTICITY ADVECTION. THIS IS SUPPORTED BY THE ETA/RUC/GFS. SNOW RATES MAY RANGE FROM 1 TO 2 INCHES PER HOUR. SOME FZRA HAS BEEN OBSERVED NORTH OF MEDFORD EARLIER...BUT MOST LOCATIONS HAVE TEMPS ABOVE FREEZING NOW. EXCEPTION MAY BE IN VALLEY LOCATIONS WHERE STRONG INVERSION IS HOLDING DOWN TEMPS. HEAVY SNOW WILL ALSO CONTINUE IN THE HIGHER ELEVATIONS OF THE SIERRA ..TAYLOR.. 12/18/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...BOI...LKN...PDT...REV...MFR...PQR... 39391884 40252000 41862008 42232251 43122257 45402189 45511851 44741731 42231521 40151489 WWWW From MCD at goshenarc.org Mon Dec 19 01:00:29 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sun, 18 Dec 2005 20:00:29 -0500 Subject: [MCD] SWOMCD Message-ID: <200512190058.jBJ0wqwi010452@mail.goshen.edu> ACUS11 KWNS 190058 SWOMCD SPC MCD 190057 UTZ000-IDZ000-NVZ000-ORZ000-WAZ000-190600- MESOSCALE DISCUSSION 2581 NWS STORM PREDICTION CENTER NORMAN OK 0657 PM CST SUN DEC 18 2005 AREAS AFFECTED...SW WA/MUCH OF ORE/SW ID/NRN UT CONCERNING...FREEZING RAIN/SNOW VALID 190057Z - 190600Z ...FZRA WILL AFFECT THE INTERIOR VALLEYS OF NW ORE/SW WA TONIGHT WITH MODERATE/HEAVY SNOW FROM THE COLUMBIA GORGE SEWD TO SW ID/NRN UT... FIRST IN A SERIES OF UPPER IMPULSES IS NOW ROTATING ONSHORE WITH AN UPPER CIRCULATION CENTER APPARENT IN EVENING WATER VAPOR IMAGERY MOVING INTO SW ORE. STAGNANT COLD AIRMASS HAS BEEN TRAPPED WITHIN THE VALLEYS FOR THE PAST FEW DAYS...AND WITH STRONG LARGE SCALE ASCENT AND MOISTURE IN PLACE...FZRA WILL RESULT ACROSS SOME LOCATIONS TONIGHT. THERE HAS BEEN FZRA DURING THE LAST COUPLE OF HOURS AT SALEM AND IN EUGENE EARLIER. 00Z SOUNDING FROM SALEM SHOWED NEAR FREEZING TEMPS FROM ABOUT 925MB-750MB...BUT RECENT MODERATE SNOW REPORTS IN/NEAR PORTLAND INDICATE THE COLUMN IS COLD ENOUGH FOR SNOW AT LEAST INITIALLY. VEERING PROFILE FROM BOTH ORE UPPER AIR SOUNDINGS IMPLIES CONTINUED WARMING...WITH A MIX OF PCPN TYPES POSSIBLE. FORECAST SOUNDINGS FROM THE NAM/RUC SUGGEST FZRA COULD SPREAD FROM PORTLAND NWD INTO THE INTERIOR VALLEYS OF SW WA BY 03Z AND NEAR OLYMPIA TOWARD 06Z. THE PTYPE ALGORITHM AND THE NCEP SREF SHOW AN EVEN STRONGER SIGNAL OF FZRA...ESPECIALLY AFTER 06Z. ACROSS NERN PORTIONS OF ORE INTO ID/UT...SNOW IS EXPECTED WITH HRLY RATES OF 1 TO 2 INCHES PER HOUR POSSIBLE...AND BOUTS OF HEAVY SNOW WILL ALSO CONTINUE OVERNIGHT ACROSS THE WASATCH. ..TAYLOR.. 12/19/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...SLC...PIH...BOI...LKN...OTX...PDT...SEW...PQR... 41311512 44102090 44762407 46692299 47432121 45381690 41701120 40691196 WWWW From MCD at goshenarc.org Mon Dec 19 15:59:44 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 19 Dec 2005 10:59:44 -0500 Subject: [MCD] SWOMCD Message-ID: <200512191558.jBJFwCcW014407@mail.goshen.edu> ACUS11 KWNS 191557 SWOMCD SPC MCD 191557 IDZ000-ORZ000-WAZ000-192000- MESOSCALE DISCUSSION 2582 NWS STORM PREDICTION CENTER NORMAN OK 0957 AM CST MON DEC 19 2005 AREAS AFFECTED...ERN/NRN ORE...SERN WA...AND WRN ID CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION VALID 191557Z - 192000Z FREEZING RAIN WILL DIMINISH IN INTENSITY OVER THE WRN COLUMBIA RIVER GORGE THROUGH 18Z...WHILE A MIX OF SLEET AND FREEZING RAIN WILL DEVELOP FURTHER EAST OVER THE COLUMBIA RIVER BASIN OF NERN ORE/SERN WA THROUGH 20Z. HRLY ACCUMULATIONS UP TO 0.10 FOR AN HOUR OR TWO WILL BE POSSIBLE. FURTHER SOUTH...LIGHT SNOW WILL CONTINUE TO DEVELOP OVER THE TREASURE VALLEY OF FAR SERN ORE/SWRN ID THROUGH 18Z...BEFORE A MIX AND THEN CHANGE OVER TO SLEET/FREEZING RAIN OCCURS IN THIS AREA BETWEEN 18-20Z. ACCUMULATIONS RATES UP TO 0.10 INCH/HR WILL BE POSSIBLE IN THIS AREA AS WELL. STRONG MID LEVEL ISENTROPIC LIFT WAS CONTRIBUTING TO AN ORGANIZED NW-SE ORIENTED BAND OF PRECIPITATION MOVING EWD ACROSS SRN WA AND ERN ORE. AS THE UPPER WAVE CONTRIBUTING TO THIS LIFTS INTO BRITISH COLUMBIA...EXPECT A STEADY EWD PROGRESS OF THIS PRECIPITATION ACROSS MUCH OF NERN ORE/SERN WA THROUGH THE EARLY AFTERNOON HOURS. RECENT RUC/NAM FORECAST SOUNDINGS INDICATE THAT LIGHT SNOW WILL CHANGE OVER TO FREEZING RAIN OVER MUCH OF THE COLUMBIA RIVER BASIN OF NERN ORE/SERN WA THROUGH 20Z. FURTHER EAST...ISENTROPIC ASCENT WAS JUST NOW MOVING INTO THE UPPER TREASURE VALLEY OF SERN ORE/SWRN ID. IN THIS AREA...STRONG WAA...EVIDENT BY 60 KT SWLY JET AT 700 MB PER MEDFORD VWP...SUGGESTS THAT LIGHT SNOW NOW DEVELOPING INTO THIS AREA WILL CHANGE OVER TO FREEZING RAIN/SLEET BETWEEN 18-20Z. ..CROSBIE.. 12/19/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MSO...BOI...OTX...PDT...SEW...PQR... 46861735 47211930 47202100 46882142 46252177 45802181 45312147 45042090 44931996 44511932 43631865 42781781 42461733 42461578 43101540 44491601 46021678 WWWW From MCD at goshenarc.org Mon Dec 19 19:59:01 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 19 Dec 2005 14:59:01 -0500 Subject: [MCD] SWOMCD Message-ID: <200512191957.jBJJvR5N021293@mail.goshen.edu> ACUS11 KWNS 191956 SWOMCD SPC MCD 191956 IDZ000-ORZ000-WAZ000-200100- MESOSCALE DISCUSSION 2583 NWS STORM PREDICTION CENTER NORMAN OK 0156 PM CST MON DEC 19 2005 AREAS AFFECTED...NRN/ERN ORE...SWRN ID AND SRN WA- CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION VALID 191956Z - 200100Z MODERATE SNOW OVER THE TREASURE VALLEY MAY CHANGEOVER TO LIGHT FREEZING RAIN THROUGH 21Z...BEFORE WEAKENING TOWARDS 00Z. FURTHER NORTH MIXED PRECIP OVER NERN ORE/SERN WA...INCLUDING MUCH OF THE COLUMBIA RIVER BASIN...WILL CONTINUE TO DIMINISH THROUGH THE AFTERNOON. HOWEVER...A NEW AREA OF FREEZING RAIN WILL REDEVELOP AFTER 22Z IN THE DESCHUTES RIVER VALLEY OF NRN ORE AND OVER THE WRN COLUMBIA RIVER BASIN/GORGE AFTER 00Z. LATEST RADAR IMAGERY INDICATES A LARGE AREA OF PRECIPITATION OVER ERN ORE...ASSOCIATED WITH MODERATE-STRONG MID LEVEL WAA/ISENTROPIC LIFT. AS OF YET...THE WAA HAS BEEN INSUFFICIENT TO ALLOW FOR A CHANGEOVER TO FREEZING RAIN IN THE TREASURE VALLEY WITH MODERATE SNOWFALL THE PRIMARY P-TYPE. GIVEN RECENT TRENDS IN OBSERVATIONS AT BURNS /ELEV 4000 FT/ INDICATING ABOVE FREEZING TEMPERATURES DEVELOPING ...THERE IS STILL SOME POTENTIAL THAT SNOW WILL CHANGEOVER TO FREEZING RAIN BEFORE PRECIPITATION DIMINISHES BY LATE THIS AFTERNOON. FURTHER NW...RADAR IMAGERY AND SURFACE OBSERVATIONS INDICATE THAT WEAKENING MIXED PRECIP RATES WILL CONTINUE OVER MUCH OF THE COLUMBIA RIVER BASIN REGION THROUGH THE REMAINDER OF THE AFTERNOON AS MID LEVEL ISENTROPIC LIFT SHIFTS EWD AWAY FROM THE AREA. UPSTREAM OF THIS AREA...ANOTHER SURGE OF STRONG MID LEVEL WAA WAS BEGINNING AHEAD OF DEEP SYSTEM WELL OFF THE ORE COAST. THE ASSOCIATED PRECIPITATION WAS ALREADY ADVANCING NWD ALONG THE CENTRAL ORE COAST AND WILLAMETTE VALLEY. AS THIS PRECIPITATION ADVANCES NEWD...SUBFREEZING AIR WILL REMAIN IN PLACE OVER THE WRN COLUMBIA RIVER BASIN...COLUMBIA GORGE AND DESCHUTES VALLEY. THUS ANOTHER ROUND OF LIGHT TO MODERATE FREEZING RAIN WILL DEVELOP BETWEEN 22-01Z. ..CROSBIE.. 12/19/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MSO...BOI...OTX...PDT...SEW...PQR... 46911830 46751993 46592117 46392195 46222219 45492219 45042202 44252169 44302124 44962022 45081900 44701828 42881643 42671594 43311556 44691617 46701708 WWWW From MCD at goshenarc.org Tue Dec 20 01:32:42 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 19 Dec 2005 20:32:42 -0500 Subject: [MCD] SWOMCD Message-ID: <200512200131.jBK1VFQm000568@mail.goshen.edu> ACUS11 KWNS 200130 SWOMCD SPC MCD 200130 WAZ000-ORZ000-200630- MESOSCALE DISCUSSION 2584 NWS STORM PREDICTION CENTER NORMAN OK 0730 PM CST MON DEC 19 2005 AREAS AFFECTED...NERN ORE/ERN WA CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION VALID 200130Z - 200630Z FREEZING RAIN WILL CONTINUE TO DEVELOP OVER THE WRN COLUMBIA RIVER BASIN/GORGE OF NRN ORE THROUGH 03Z. FREEZING RAIN WILL EVENTUALLY DEVELOP INTO THE ERN SLOPES OF THE CASCADES AND COLUMBIA RIVER BASIN OF ERN WA BETWEEN 03-06Z. A COUPLE HOUR PERIOD OF HRLY PRECIP RATES UP TO 0.05 INCH WILL BE POSSIBLE...ESPECIALLY WITHIN 1-2 HOURS OF ONSET OF PRECIPITATION. AN AREA OF MOD-OCCASIONALLY HEAVY PRECIPITATION OVER NWRN ORE HAS DEVELOPED IN AN AREA OF MODERATE WAA AHEAD OF DEEP UPPER CYCLONE WELL OFF THE ORE COAST. THIS PRECIPITATION WILL CONTINUE TO SPREAD NEWD INTO THE COLUMBIA RIVER BASIN THROUGH THE LATE EVENING HOURS ON THE HEAL OF A 50-60 KT LOW LEVEL SSWLY JET. RECENT SURFACE OBSERVATIONS INDICATE HRLY RAINFALL RATES UP TO 0.2O INCH OVER THE NRN WILLAMETTE VALLEY. ALTHOUGH LOW LEVEL FLOW WILL REMAIN SSWLY WHICH SHOULD AID IN SOME SUBSIDENCE ON THE LEE-SIDE OF THE CASCADES...AND THUS LOWER HRLY PRECIP AMOUNTS...SUFFICIENTLY DEEP VERTICAL MOTION SHOULD ALLOW FOR LIGHT TO OCCASIONALLY MODERATE FREEZING RAIN TO DEVELOP INTO THE SERN SLOPES OF THE WA CASCADES AND COLUMBIA RIVER BASIN OF WA BETWEEN 03-06Z. FURTHER SOUTH...AS THE BULK OF THE LOW LEVEL LIFT/PRECIP CONTINUES TO MOVE NWD...EXPECT A DIMINISHING OF THE FREEZING RAIN RATES OVER THE DESCHUTES VALLEY THROUGH 06Z. ..CROSBIE.. 12/20/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...OTX...PDT...PQR... 47211981 47692030 47472102 47142094 46002160 45532231 45032185 44682168 44632070 44672056 45421981 46461970 WWWW From MCD at goshenarc.org Wed Dec 28 14:52:01 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 28 Dec 2005 09:52:01 -0500 Subject: [MCD] SWOMCD Message-ID: <200512281453.jBSErjeA027138@mail.goshen.edu> ACUS11 KWNS 281453 SWOMCD SPC MCD 281452 OHZ000-KYZ000-MIZ000-INZ000-TNZ000-ILZ000-281645- MESOSCALE DISCUSSION 2594 NWS STORM PREDICTION CENTER NORMAN OK 0852 AM CST WED DEC 28 2005 AREAS AFFECTED...E CENTRAL IL/IN/WRN OH/SRN LOWER MI/CENTRAL KY/NRN MIDDLE TN CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 281452Z - 281645Z THUNDERSTORMS SHOULD CONTINUE TO SPREAD ENEWD NEAR/JUST E OF EWD-MOVING UPPER LOW CENTER. MARGINALLY-SEVERE HAIL WILL REMAIN POSSIBLE WITH A FEW STRONGER CELLS...THOUGH WW NOT ANTICIPATED ATTM. LATEST RADAR IMAGERY SHOWS AN ARC OF STORMS NOW MOVING ENEWD ACROSS THE MIDDLE OH VALLEY REGION...JUST AHEAD OF UPPER LOW NOW CENTERED OVER SRN IL. COLD AIR ALOFT /AROUND -22 C AT 500 MB/ IS CONTRIBUTING TO AN ELEVATED LAYER OF STEEP LAPSE RATES...WITH 200 TO 400 J/KG MOST-UNSTABLE CAPE EVIDENT ON AREA 12Z RAOBS BETWEEN 850 AND 300 MB. WITH 40 TO 50 KT SSWLY FLOW AT MID LEVELS JUST AHEAD OF THE UPPER LOW...DEEP-LAYER SHEAR IS SUFFICIENT FOR SOME SUSTAINED/PERHAPS WEAKLY-ROTATING UPDRAFTS. THOUGH OVERALL STORM INTENSITY WILL REMAIN LIMITED DUE TO MARGINAL INSTABILITY...A FEW OF THE STRONGER STORMS WILL REMAIN CAPABLE OF PRODUCING 1/2 TO 3/4" HAIL OVER THE NEXT FEW HOURS AS STORMS SPREAD TOWARD ERN KY/WRN OH/SRN LOWER MI. ..GOSS.. 12/28/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...RLX...CLE...JKL...ILN...DTX...LMK...IWX...GRR...OHX...IND...LOT...ILX... 39978783 41858559 42148439 41818329 40768287 38528316 36768497 36158710 37758620 39168633 WWWW From MCD at goshenarc.org Wed Dec 28 17:20:25 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 28 Dec 2005 12:20:25 -0500 Subject: [MCD] SWOMCD Message-ID: <200512281722.jBSHM4oA027360@mail.goshen.edu> ACUS11 KWNS 281721 SWOMCD SPC MCD 281721 KYZ000-VAZ000-TNZ000-NCZ000-GAZ000-ALZ000-281915- MESOSCALE DISCUSSION 2595 NWS STORM PREDICTION CENTER NORMAN OK 1121 AM CST WED DEC 28 2005 AREAS AFFECTED...NRN AL/MIDDLE AND ERN TN/CENTRAL AND ERN KY CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 281721Z - 281915Z THREAT FOR HAIL/LOCALLY DAMAGING WINDS WILL LIKELY INCREASE OVER THE NEXT 1 TO 2 HOURS WITH STRENGTHENING STORMS. PARTS OF THIS AREA WILL BE MONITORED FOR POSSIBLE WW. AIRMASS CONTINUES TO DESTABILIZE AHEAD OF COLD FRONT...AS COOLING ALOFT ASSOCIATED WITH UPPER LOW CONTINUES TO OVERSPREAD WARMING/MOISTENING BOUNDARY LAYER. CONVECTION IS INCREASING IN INTENSITY ATTM OVER CENTRAL KY...WITH NEW CONVECTIVE DEVELOPMENT OCCURRING SWWD ACROSS MIDDLE TN AND INTO NRN AL. EXPECT THIS TREND TO CONTINUE AS FURTHER AIRMASS DESTABILIZATION OCCURS THROUGH THE AFTERNOON. THOUGH NOT AS STRONG AS FURTHER S...DEEP-LAYER SHEAR ACROSS THIS REGION IS SUFFICIENT TO SUPPORT ORGANIZED/WEAKLY-ROTATING UPDRAFTS. THIS COMBINED WITH SLOW INCREASE IN AVAILABLE INSTABILITY SUGGESTS THAT STORMS WILL BECOME CAPABLE OF PRODUCING MARGINALLY-SEVERE HAIL/WIND GUSTS OVER THE NEXT COUPLE OF HOURS. ..GOSS.. 12/28/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MRX...JKL...FFC...LMK...OHX...BMX...HUN... 37888507 38018400 37458304 34898443 33348728 35388627 36558592 WWWW From MCD at goshenarc.org Wed Dec 28 17:58:20 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 28 Dec 2005 12:58:20 -0500 Subject: [MCD] SWOMCD Message-ID: <200512281759.jBSHxw6K011500@mail.goshen.edu> ACUS11 KWNS 281759 SWOMCD SPC MCD 281758 GAZ000-FLZ000-ALZ000-282000- MESOSCALE DISCUSSION 2596 NWS STORM PREDICTION CENTER NORMAN OK 1158 AM CST WED DEC 28 2005 AREAS AFFECTED...SRN AL/FL PNHDL/SWRN INTO CENTRAL GA CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 281758Z - 282000Z SEVERE STORM THREAT FORECAST TO INCREASE ACROSS THIS REGION OVER THE NEXT SEVERAL HOURS. WW MAY BE REQUIRED. LATEST RADAR LOOP INDICATES AN AXIS OF THUNDERSTORMS EXTENDING FROM WRN NC SWWD ACROSS NRN GA INTO SERN AL -- WELL AHEAD OF SURFACE FRONT. AIRMASS DESTABILIZATION IS UNDERWAY ACROSS THE SURFACE WARM SECTOR/NEAR AND BEHIND THIS INITIAL LINE OF STORMS...AS MOISTENING BOUNDARY LAYER COUPLED WITH DAYTIME HEATING HAS IS NOW YIELDING MEAN-LAYER CAPE 500 TO 1000 J/KG. THOUGH CONVERGENCE REMAINS FAIRLY WEAK ALONG COLD FRONT ATTM AND NO OTHER OBVIOUS LOW-LEVEL CONVERGENCE AXES EXIST...LARGE-SCALE LIFT IS OCCURRING ACROSS THIS REGION AS SEVERAL WEAK FEATURES ALOFT ROTATE THROUGH THE BASE OF LARGER-SCALE MID-LEVEL TROUGH. WITH TIME...EXPECT MULTIPLE BANDS OF STORMS TO EVOLVE ACROSS THIS REGION. DEEP-LAYER SHEAR IS SUFFICIENT FOR ORGANIZED/SUPERCELL CONVECTION...WITH WSWLY MID-LEVEL FLOW NEAR 60 KT ABOVE SURFACE SSWLYS. THUS...EXPECT THREAT FOR HAIL AND LOCALLY DAMAGING WINDS TO INCREASE THROUGH THE AFTERNOON AS STORMS DEVELOP ACROSS THIS REGION. THOUGH LOW-LEVEL TURNING IS SOMEWHAT LIMITED...RAPID INCREASE IN FLOW WITH HEIGHT ABOVE THE SURFACE IS YIELDING 0-1 KM SHEAR SUFFICIENT FOR LOW-LEVEL ROTATION. THIS COMBINED WITH DEWPOINTS IN THE LOW 60S SUGGEST A THREAT FOR A TORNADO OR TWO AS WELL -- PARTICULARLY FROM SWRN GA SWWD. ..GOSS.. 12/28/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...CHS...JAX...FFC...TAE...BMX...MOB... 29808762 31548648 33418405 33508271 32408222 31158266 29578392 29518572 WWWW From MCD at goshenarc.org Wed Dec 28 20:18:12 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 28 Dec 2005 15:18:12 -0500 Subject: [MCD] SWOMCD Message-ID: <200512282019.jBSKJnMN008416@mail.goshen.edu> ACUS11 KWNS 282019 SWOMCD SPC MCD 282019 SCZ000-GAZ000-FLZ000-ALZ000-282215- MESOSCALE DISCUSSION 2597 NWS STORM PREDICTION CENTER NORMAN OK 0219 PM CST WED DEC 28 2005 AREAS AFFECTED...ERN AL/MUCH OF GA/W CENTRAL SC CONCERNING...TORNADO WATCH 898... VALID 282019Z - 282215Z SEVERE/TORNADO THREAT CONTINUES ACROSS MUCH OF WW -- PARTICULARLY NEAR AND E OF THE AL/GA BORDER. WITH SEVERAL SUPERCELLS NOW ONGOING ACROSS SWRN AND CENTRAL GA MOVING EWD...NEW WW MAY BE REQUIRED SHORTLY E OF CURRENT WW. LATEST RADAR IMAGERY SHOWS SEVERAL SEVERE/SUPERCELL STORMS ACROSS ERN AL AND INTO GA...AHEAD OF EWD-MOVING COLD FRONT. THOUGH NO TORNADOES HAVE BEEN CONFIRMED THUS FAR...LOW-LEVEL ROTATION REMAINS EVIDENT IN SEVERAL OF THE STRONGER STORMS. DEWPOINTS ARE GENERALLY IN THE UPPER 50S TO LOW 60S OVER WW AREA...CONTRIBUTING 500 TO 1000 J/KG MEAN-LAYER CAPE WITHIN AND JUST S OF WW. INSTABILITY DECREASES WITH EWD EXTENT ACROSS GA...AS SLY SURFACE TRAJECTORIES SOMEWHAT MORE ORIENTED OUT OF THE FL PENINSULA ARE MAINTAINING LOWER /MID 50S/ DEWPOINTS. NONETHELESS...AS REGION OF UVV EVIDENT ON WV IMAGERY OVER ERN AL/WRN GA /LIKELY THE LEFT EXIT REGION OF THE UPPER JET/ MOVES EWD WITH TIME...EXPECT STORMS TO ALSO SPREAD EWD TOWARD THE GA COAST/WRN SC. THOUGH SLOW WEAKENING TREND APPEARS LIKELY AS STORMS MOVE EWD INTO LESS UNSTABLE AIR...INSTABILITY SHOULD STILL BE SUFFICIENT TO SUPPORT VIGOROUS CONVECTION. THEREFORE...WITH A THREAT FOR AT LEAST HAIL AND DAMAGING WINDS LIKELY TO EXTEND E OF WW...NEW WW IS BEING CONSIDERED FOR ERN GA AND VICINITY. ..GOSS.. 12/28/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...CHS...CAE...JAX...FFC...TAE...BMX...MOB... 33538591 33868512 33808163 32388126 30678194 30718479 31728688 32448671 WWWW From MCD at goshenarc.org Wed Dec 28 22:57:42 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 28 Dec 2005 17:57:42 -0500 Subject: [MCD] SWOMCD Message-ID: <200512282259.jBSMxJkn004804@mail.goshen.edu> ACUS11 KWNS 282258 SWOMCD SPC MCD 282258 SCZ000-GAZ000-290030- MESOSCALE DISCUSSION 2598 NWS STORM PREDICTION CENTER NORMAN OK 0458 PM CST WED DEC 28 2005 AREAS AFFECTED...SERN GA/SRN AND CNTRL SC CONCERNING...TORNADO WATCH 899... VALID 282258Z - 290030Z THE SEVERE THREAT SHOULD CONTINUE ACROSS TORNADO WATCH 899 OVER THE NEXT FEW HOURS. THE SEVERE THREAT MAY ALSO EXPAND NEWD INTO CNTRL SC AS STRONG CELLS DRIFT NEWD LATE THIS AFTERNOON. WATER VAPOR IMAGERY CURRENTLY SHOWS A SHORTWAVE TROUGH OVER ERN GA EMBEDDED IN THE LARGER ERN US TROUGH. THIS FEATURE WILL CONTINUE TO MOVE NEWD THROUGH EARLY THIS EVENING ALLOWING THE LARGE CLUSTER OF STORMS OVER GA AND SRN SC TO EXPAND NWD. SFC DEWPOINTS DROP OFF QUICKLY FROM THE MID 50S F INTO THE 40S F EAST OF INTERSTATE 95. AS THE CONVECTION MOVES NEWD INTO THE COLUMBIA AREA...LARGE HAIL AND ISOLATED WIND DAMAGE WILL BE POSSIBLE WITH THE STRONGER CELLS. GRADUAL WEAKENING SHOULD OCCUR WITH THE STORMS THAT MOVE NEWD AND ENCOUNTER THE WEAKER INSTABILITY ACROSS ERN SC. ..BROYLES.. 12/28/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...ILM...CHS...CAE...JAX...FFC...TAE... 33777980 33207991 32048119 31248234 31468310 32128337 33438212 34238108 34208025 WWWW From MCD at goshenarc.org Thu Dec 29 18:28:50 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 29 Dec 2005 13:28:50 -0500 Subject: [MCD] SWOMCD Message-ID: <200512291830.jBTIUOkt026995@mail.goshen.edu> ACUS11 KWNS 291829 SWOMCD SPC MCD 291829 SDZ000-NDZ000-300030- MESOSCALE DISCUSSION 2599 NWS STORM PREDICTION CENTER NORMAN OK 1229 PM CST THU DEC 29 2005 AREAS AFFECTED...NORTHERN SOUTH DAKOTA...SOUTHERN NORTH DAKOTA CONCERNING...WINTER MIXED PRECIPITATION VALID 291829Z - 300030Z A SWATH OF MODERATE TO HEAVY SNOW LOCALLY PRECEEDED BY MIXED PRECIPITATION IS EXPECTED ACROSS NORTHERN SOUTH DAKOTA AND SOUTHERN NORTH DAKOTA THIS AFTERNOON WITH LOCALIZED SNOWFALL RATES APPROACHING ONE INCH PER HOUR. A UPPER LEVEL STRONG SHORT WAVE TROUGH EVIDENT IN WATER VAPOR IMAGERY AND RUC ANALYSES OVER CENTRAL COLORADO WILL PROGRESS EASTWARD AND COMBINE WITH LOW LEVEL CYCLOGENESIS TO PRODUCE DEEP LAYER ASCENT OVER THE THREAT AREA THIS AFTERNOON. STRONG 800-700 MB LAYER FRONTOGENESIS IN RUC FCST ALSO HELPS FOCUS ASCENT NEAR ND...SD BORDER AREA THIS AFTERNOON. AT 14Z... 105 KNOT WINDS AT 9KM WERE OBSERVED AT THE PLATTEVILLE CO WIND PROFILER AS THE JET STREAK AXIS SLID EASTWARD ACROSS COLORADO. SITUATION IS COMPLICATED BY A WEAKER LEAD SHORTWAVE CURRENTLY EVIDENT IN WV AND RUC ANALYSES OVER SW SD CURRENTLY CONTRIBUTING TO MODERATE SNOWFALL OVER SOUTHERN ND. BOTH RUC AND SREF APPEAR TO HAVE A POOR HANDLE ON THIS FEATURE. MODIFIED PACIFIC AIRMASS IS EVIDENT OVER PORTIONS OF NORTHWEST NEBRASKA AND EASTERN WY AND MT WITH GPS PW OF NEARLY THREE QUARTER INCH CURRENTLY OBSERVED NEAR CDR EARLIER TODAY. RUC AND NCEP SREF AGREE THAT LOCALIZED INCH PER HOUR SNOWFALL RATES ARE POSSIBLE...IN PARTICULAR LATE IN THE PERIOD. TYPICAL POLAR AIRMASS IS ABSENT ACROSS THE EASTERN US SO COOLING OF THE LAYER THROUGH DEEP ASCENT AND EVAPORATION WILL BE NECESSARY IN PORTIONS OF THE THREAT AREA BEFORE THE ONSET OF FROZEN PRECIPITATION. THE PRESENCE OF THE POORLY HANDLED LEAD SHORTWAVE COMBINED WITH OBSERVED MODERATE RAIN WITH ABOVE FREEZING TEMPERATURE AT MBG SD AT 18Z SHIFTED FOCUS OF WINTER PRECIPITATION SLIGHTLY NORTHWARD BUT CONFIRMS POTENTIAL FOR INCH AN HOUR RATES IN SNOW AREAS. 12Z ABR SOUNDING HAD ONLY A SHALLOW ABSOLUTELY STABLE LAYER WITH WET BULB TEMPERATURES ABOVE ZERO DESPITE 150MB DEEP LAYER WITH A DRY BULB TEMPERATURE ABOVE FREEZING. MODEL SOUNDINGS SUGGEST THAT PRECIPITATION WILL TRANSITION FROM FREEZING RAIN TO MIXED PRECIPITATION AND MAINLY SNOW OVER NORTHEAST SD BETWEEN 21 AND 03Z. HEAVIEST PRECIPITATION RATES WILL SPREAD FROM WEST TO EAST ACROSS THE THEAT AREA THIS AFTERNOON AND EVENING. ..SCHNEIDER.. 12/29/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...FGF...FSD...ABR...BIS...UNR... 45980223 46640089 46709924 46209760 45419681 43999689 45099843 45559949 45510117 WWWW From MCD at goshenarc.org Fri Dec 30 00:07:42 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 29 Dec 2005 19:07:42 -0500 Subject: [MCD] SWOMCD Message-ID: <200512300009.jBU09F5Y027398@mail.goshen.edu> ACUS11 KWNS 300008 SWOMCD SPC MCD 300008 IAZ000-MNZ000-WIZ000-SDZ000-NEZ000-300415- MESOSCALE DISCUSSION 2600 NWS STORM PREDICTION CENTER NORMAN OK 0608 PM CST THU DEC 29 2005 AREAS AFFECTED...SE SD...SRN MN...NRN IA CONCERNING...WINTER MIXED PRECIPITATION VALID 300008Z - 300415Z A LARGE AREA OF FREEZING RAIN MIXED WITH SNOW WILL SPREAD EWD AND GRADUALLY CHANGE OVER TO ALL SNOW ACROSS SE SD...SRN MN AND NRN IA. WATER VAPOR IMAGERY CURRENTLY SHOWS AN UPPER-LEVEL TROUGH OVER WRN SD AND WRN NEB WITH A DRY SLOT AND DEFORMATION ZONE EXPANDING EWD ACROSS ERN SD AND NE NEB. STRONG LIFT ASSOCIATED WITH THE LEFT FRONT QUADRANT OF THE MID-LEVEL JET AND STRONG DIVERGENCE ALOFT SHOWN ON THE SHORT-TERM MODEL FORECASTS IS RESULTING IN WIDESPREAD PRECIPITATION EXTENDING EWD FROM THE DEFORMATION ZONE. FORECAST SOUNDINGS ACROSS SRN MN AND NRN IA SHOW AN ABOVE FREEZING LAYER FROM 900 TO 800 MB. AS THE SYSTEM DRIFTS EWD TONIGHT THIS WARM LAYER WILL ERODE FROM WEST TO EAST RESULTING IN A CHANGEOVER TO ALL SNOW. ISOLATED HEAVY SNOWFALL RATES OF GREATER THAN 1 INCH PER HOUR WILL BE POSSIBLE ESPECIALLY AS THE WRAP AROUND ASSOCIATED WITH THE MID-LEVEL LOW DRIFTS EWD INTO SE SD AROUND MIDNIGHT. THIS AREA OF HEAVIER SNOWFALL SHOULD DRIFT EWD INTO SRN MN AND NRN IA DURING THE OVERNIGHT HOURS. ..BROYLES.. 12/30/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...ARX...MPX...DMX...FSD...OAX...ABR... 42689337 42759776 43299893 43989893 44699749 44759354 44239166 43159141 WWWW From MCD at goshenarc.org Fri Dec 30 00:17:19 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 29 Dec 2005 19:17:19 -0500 Subject: [MCD] SWOMCD Message-ID: <200512300018.jBU0IpuU030184@mail.goshen.edu> ACUS11 KWNS 300018 SWOMCD SPC MCD 300017 MNZ000-SDZ000-NDZ000-300615- MESOSCALE DISCUSSION 2601 NWS STORM PREDICTION CENTER NORMAN OK 0617 PM CST THU DEC 29 2005 AREAS AFFECTED...SE NORTH DAKOTA...NE SOUTH DAKOTA...WEST CNTRL MINNESOTA CONCERNING...HEAVY SNOW VALID 300017Z - 300615Z SNOWFALL RATES WILL APPROACH 1 INCH PER HOUR OVER SOUTHEAST NORTH DAKOTA...NORTHEAST SOUTH DAKOTA...AND WEST CENTRAL MINNESOTA. A LOW PRESSURE SYSTEM OVER CENTRAL SOUTH DAKOTA WILL CONTINUE TO MOVE EASTWARD INTO NORTHERN IOWA. THE UPWARD VERTICAL MOTION ASSOCIATED WITH A STRONG UPPER LEVEL WAVE MOVING THROUGH THE AREA...COUPLED WITH THE LEFT EXIT REGION OF A JET AND DECENT UPPER DIVERGENCE...WILL AID IN THE DEVELOPMENT OF SNOW BANDS AND HEAVY SNOW ACROSS THE REGION FOR MOST OF THE EVENING. MODERATE TO HEAVY SNOWFALL WILL BE THE MAJOR PRECIPITATION TYPE ACROSS THE NORTHERN PART OF THE REGION. ACCORDING TO THE GFS AND NAM...WHICH ARE IN FAIRLY GOOD AGREEMENT...SOME LOCALLY TRANSIENT SLEET AND FREEZING RAIN...ALONG WITH SNOW...WILL OCCUR IN THE SOUTHERN PART OF THE REGION. THE STORM SYSTEM WILL CONTINUE TO MOVE EASTWARD THROUGH THE PERIOD AND PRECIPITATION IS EXPECTED TO DECREASE TOWARDS FRIDAY MORNING. ..LEVIT.. 12/30/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MPX...FGF...ABR...BIS... 46900166 47170041 47209857 47209689 47049542 46209494 45659583 45369703 45269839 45300057 45680171 WWWW From MCD at goshenarc.org Fri Dec 30 05:40:11 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Fri, 30 Dec 2005 00:40:11 -0500 Subject: [MCD] SWOMCD Message-ID: <200512300541.jBU5fgb8004043@mail.goshen.edu> ACUS11 KWNS 300541 SWOMCD SPC MCD 300540 IDZ000-ORZ000-301145- MESOSCALE DISCUSSION 2602 NWS STORM PREDICTION CENTER NORMAN OK 1140 PM CST THU DEC 29 2005 AREAS AFFECTED...NERN OREGON INTO EXTREME SWRN ID CONCERNING...HEAVY SNOW VALID 300540Z - 301145Z MDT TO HVY SNOW IS EXPECTED TO DEVELOP BY AROUND 09Z MAINLY OVER NERN OREGON...WITH 1.50-2.00 IN/HR SNOW RATES POSSIBLE IN UPSLOPE REGION AND 1.00 IN/HR POSSIBLE LOWER ELEVATIONS. SNOW WILL THEN SHIFT EWD TOWARD 12Z INTO SWRN ID WHERE A MIXTURE OF RAIN AND HEAVY WET SNOW APPEAR LIKELY INTO THE LOWER TREASURE VALLEY. PRECIPITATION SHIELD IS EXPECTED TO GRADUALLY FILL IN ACROSS ERN OREGON AS SWLY FLOW BRINGS IN HIGHER PRECIPITABLE WATER CONTENT. UPWARD VERTICAL MOTIONS FIELDS WILL INCREASE AS ZONE OF FRONTOGENETICAL FORCING MATERIALIZES NEAR LEADING EDGE OF WARM/MOIST ADVECTION ALOFT. LIFTING ZONE IS EXPECTED TO LIE ALONG A NW-SE AXIS FROM THE MTNS OF NERN OREGON INTO FAR SWRN ID BY 12Z. RUC AND NAM FORECAST SOUNDINGS INDICATE STRONG VERTICAL MOTION CENTERED AROUND 550-500 MB LAYER WHICH IS COINCIDENT WITH FAVORABLE TEMPERATURE LAYER FOR DENDRITIC GROWTH. THIS...COMBINED WITH SATURATED AND SUB-ZERO PROFILES IN THE SFC-700 MB LAYER AND SURFACE WET BULB ZERO TEMPERATURES NEAR FREEZING SHOULD RESULT IN LOCALLY HEAVY SNOWFALL RATES...ESPECIALLY IN THE HIGHER TERRAIN WHERE SLY FLOW WILL ENHANCE UPSLOPE. PRECIPITATION MAY BEGIN AS RAIN IN THE LOWER TREASURE VALLEY...BUT COULD CHANGE TO HVY WET SNOW DURING HEAVIEST PRECIPITATION RATE PERIOD...WHICH WILL GENERALLY OCCUR AFTER 12Z. ..JEWELL.. 12/30/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...BOI...PDT... 44081904 44981929 45581858 45641758 45581746 45201696 44941673 44301665 43871676 43321698 43291819 43641860 WWWW From MCD at goshenarc.org Fri Dec 30 05:45:00 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Fri, 30 Dec 2005 00:45:00 -0500 Subject: [MCD] SWOMCD Message-ID: <200512300546.jBU5kVbb005506@mail.goshen.edu> ACUS11 KWNS 300546 SWOMCD SPC MCD 300545 MNZ000-IAZ000-WIZ000-SDZ000-NEZ000-300945- MESOSCALE DISCUSSION 2603 NWS STORM PREDICTION CENTER NORMAN OK 1145 PM CST THU DEC 29 2005 AREAS AFFECTED...ERN SD...SRN AND CNTRL MN...NRN IA CONCERNING...HEAVY SNOW VALID 300545Z - 300945Z AREAS OF HEAVY SNOW WILL CONTINUE ACROSS ERN SD...SRN AND CNTRL MN AND NRN IA DURING THE OVERNIGHT PERIOD. SNOWFALL RATES GREATER THAN 1 INCH PER HOUR WILL BE POSSIBLE IN THE HEAVIER SNOW BANDS. WATER VAPOR IMAGERY CURRENTLY SHOWS AN UPPER-LOW LOCATED ACROSS THE CNTRL DAKOTAS. A SHORTWAVE TROUGH EXTENDED SWD ACROSS CNTRL NEB WITH A DEFORMATION ZONE SETTING UP ACROSS WRN IA AND SERN SD. STRONG LIFT ASSOCIATED WITH THE TROUGH AND THE LEFT EXIT REGION OF THE MID-LEVEL JET WILL CONTINUE TO SUPPORT WIDESPREAD SNOWFALL ACROSS THE REGION OVERNIGHT. FORECAST SOUNDINGS ACROSS SRN MN...ERN SD AND NW IA SHOW THAT THE WARM LAYER BETWEEN 900 AND 800 MB THAT WAS PRESENT EARLIER HAS COOLED BELOW FREEZING IN MOST AREAS. AS A RESULT...SNOW WILL BE THE FAVORED MODE OF PRECIPITATION ALTHOUGH A FEW SPOTS OF FREEZING RAIN AND/OR SLEET WILL STILL BE POSSIBLE. THE STRONG LARGE-SCALE ASCENT AND ISENTROPIC LIFT NORTHEAST OF THE DEFORMATION ZONE WILL CONTINUE TO RESULT IN BANDS OF MODERATE TO HEAVY SNOW. THE HEAVIEST SNOWBANDS SHOULD BE ACROSS SE SD...FAR NRN IA AND SRN MN WHERE THE STRONGEST DIVERGENCE ALOFT SHOULD BE LOCATED. ..BROYLES.. 12/30/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...ARX...MPX...DMX...FSD...OAX...ABR... 42759727 43359805 44569811 45459724 45639572 45579387 44959255 43969202 42919279 42569537 42609557 WWWW From MCD at goshenarc.org Sat Dec 31 17:54:47 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sat, 31 Dec 2005 12:54:47 -0500 Subject: [MCD] SWOMCD Message-ID: <200512311756.jBVHuSXi030842@mail.goshen.edu> ACUS11 KWNS 311755 SWOMCD SPC MCD 311755 CAZ000-312000- MESOSCALE DISCUSSION 2604 NWS STORM PREDICTION CENTER NORMAN OK 1155 AM CST SAT DEC 31 2005 AREAS AFFECTED...SACRAMENTO VALLEY CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 311755Z - 312000Z ...LOW TOPPED SUPERCELLS MAY DEVELOP ACROSS THE SACRAMENTO VALLEY... LEADING EDGE OF STRONGER CVA IS SPREADING ACROSS THE COASTAL RANGE TOWARD THE SACRAMENTO VALLEY LATE THIS MORNING. MUCH DRIER MID LEVELS AND PARTIAL CLEARING ACROSS THE VALLEY WILL ALLOW FOR SOME HEATING OVER THE NEXT FEW HOURS..ALTHOUGH SFC TEMPS MAY STRUGGLE TO REACH THE LOWER 60S. UPSTREAM...LATEST DIAGNOSTIC DATA SUGGESTS STEEPER LOW-MID LEVEL LAPSE RATES...7C/KM...AND 3KM CAPE...IN EXCESS OF 100J/KG...WILL SPREAD INTO THE VALLEY ENHANCING THE PROSPECT FOR ROBUST CONVECTION. ADDITIONALLY...BACKED VALLEY FLOW SHOULD PROVE BENEFICIAL FOR SUSTAINING LOW-TOPPED CONVECTION...POSSIBLY AIDING STORM ROTATION AND SUPERCELL CHARACTERISTICS. HAIL IS THE MOST LIKELY SEVERE THREAT WITH THIS ACTIVITY...ALTHOUGH A BRIEF TORNADO IS ALSO POSSIBLE. ..DARROW.. 12/31/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...STO...MTR... 37662145 40252294 40862202 39452091 38192011 WWWW From MCD at goshenarc.org Sat Dec 31 18:31:35 2005 From: MCD at goshenarc.org (Mesoscale Convective Discussions) Date: Sat, 31 Dec 2005 13:31:35 -0500 Subject: [MCD] SWOMCD Message-ID: <200512311833.jBVIXGaU012212@mail.goshen.edu> ACUS11 KWNS 311832 SWOMCD SPC MCD 311832 CAZ000-312330- MESOSCALE DISCUSSION 2605 NWS STORM PREDICTION CENTER NORMAN OK 1232 PM CST SAT DEC 31 2005 AREAS AFFECTED...SIERRA MOUNTAINS CONCERNING...HEAVY SNOW VALID 311832Z - 312330Z HEAVY WET SNOW WILL CONTINUE/SPREAD SOUTHWARD ACROSS THE HIGHER ELEVATIONS OF THE SOUTHERN SIERRA MOUNTAINS THROUGH THE AFTERNOON. SNOW RATES OF 2-3 IN/HR WILL BE POSSIBLE...NAMELY ABOVE 7000-7500 FT. WATER VAPOR IMAGERY PORTRAYS COMPACT SHORTWAVE TROUGH/VORTICITY MAXIMA MOVING EASTWARD ALONG THE NORTHERN CA COAST. MESONET OBSERVATIONS GENERALLY INDICATE SNOW LEVELS AROUND 6000-6500 FT ACROSS THE NORTHERN SIERRAS /NORTH 0F I-80/...WITH 7000-7500 FT OR HIGHER SNOW LEVELS PROGRESSIVELY SOUTHWARD ACROSS THE CENTRAL/SOUTHERN SIERRAS. SNOW LEVELS SHOULD INITIALLY REMAIN RELATIVELY STEADY STATE ACROSS THE SOUTHERN SIERRAS ATTRIBUTABLE TO MODEST WARM AIR ADVECTION...BUT BEGIN LOWERING BY MID/LATE AFTERNOON AS CORE OF UPPER TROUGH/COLD POCKET TRANSITIONS EASTWARD. IN PRESENCE OF DPVA/STRONG OROGRAPHIC FORCING AND STEEPENING LAPSE RATES/CONVECTIVE ENHANCEMENT...HIGH PRECIPITABLE WATER ENVIRONMENT /1.23 PW PER SPECIAL 15Z OAKLAND ROAB -- 200+ PERCENT OF NORMAL/ WILL CONTRIBUTE TO HEAVY WET SNOW RATES OF 2-3 IN/HR OR GREATER...ESPECIALLY FOR W/SW FACING SLOPES OF THE SOUTHERN SIERRAS INTO EARLY EVENING. ..GUYER.. 12/31/2005 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...VEF...REV...HNX...STO... 36661900 37351957 38552055 39292095 39342033 38401944 37341858 36751833 36261818 36191832 36251869 36351883 WWWW