From mcd at goshenarc.org Sun Nov 5 18:21:46 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Sun, 05 Nov 2006 13:21:46 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 051823 SWOMCD SPC MCD 051823 OKZ000-TXZ000-052100- MESOSCALE DISCUSSION 2175 NWS STORM PREDICTION CENTER NORMAN OK 1223 PM CST SUN NOV 05 2006 AREAS AFFECTED...NRN TX AND SRN OK CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE VALID 051823Z - 052100Z TSTMS WITH HAIL MAY INCREASE THROUGH THE AFTERNOON ACROSS PARTS OF THE RED RIVER VALLEY. A WATCH IS POSSIBLE AS VIGOROUS CONVECTION INCREASES OVER THE NEXT FEW HOURS. STRONG VORT MAX WAS EVIDENT IN WATER VAPOR LOOP AND SHORT TERM MODEL GUIDANCE CROSSING THE TX PNHDL ATTM. DPVA AND STEEP LAPSE RATE PLUME ASSOCIATED WITH THIS IMPULSE WERE ACTING IN CONCERT WITH MODEST LOW LEVEL MOISTURE RETURN ACROSS THE SRN PLAINS TO PROVOKE A BAND OF ELEVATED TSTMS FROM WHEELER COUNTY TX TO CUSTER COUNTY OK. MEANWHILE... BREAKS IN CLOUD COVER ACROSS NRN TX AND SWRN OK HAVE ALLOWED BOUNDARY LAYER HEATING AND WEAK WARM SECTOR DEVELOPMENT ACROSS THESE AREAS. VISIBLE SATELLITE IMAGERY WAS SHOWING CU FIELD BECOMING MORE AGITATED ACROSS THIS ZONE AND MLCAPE HAS CLIMBED TO ABOUT 500 J/KG ABOVE WEAKLY CAPPED/STABLE BOUNDARY LAYER AIR MASS. LATEST GUIDANCE CONTINUES TO SUGGEST THAT CONVECTION WILL INCREASE IN COVERAGE THIS AFTERNOON ACROSS THE WARM SECTOR. THIS WILL OCCUR COINCIDENT WITH MAXIMUM IN DIURNAL DESTABILIZATION...AND AS STRONGER DYNAMIC FORCING WITH THE SHORT WAVE TROUGH ACTS ON THE APEX OF LOW LEVEL THETA-E AXIS. SHEAR AND INSTABILITY PARAMETERS SHOULD MARGINALLY SUPPORT SUPERCELL STRUCTURE AND HAIL PRODUCTION FROM A FEW STORMS...ESPECIALLY OVER PARTS OF NORTH TX WITH TIME. EVOLUTION OF THIS SCENARIO WILL CONTINUE TO BE MONITORED AND A SEVERE TSTM WATCH IS POSSIBLE AS THE AFTERNOON PROGRESSES. ..CARBIN.. 11/05/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...TSA...FWD...OUN...LUB...AMA... 33539870 33689928 33780012 33800058 33890084 34120096 34380079 34820032 35000004 35189972 35479906 35439797 34929695 34599598 33809590 33399614 33079690 33359781  From mcd at goshenarc.org Sun Nov 5 21:25:03 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Sun, 05 Nov 2006 16:25:03 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 052127 SWOMCD SPC MCD 052126 OKZ000-TXZ000-052230- MESOSCALE DISCUSSION 2176 NWS STORM PREDICTION CENTER NORMAN OK 0326 PM CST SUN NOV 05 2006 AREAS AFFECTED...SRN OK AND NRN TX CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 052126Z - 052230Z TSTMS CONTINUE TO INCREASE IN COVERAGE ACROSS PARTS OF SWRN OK AND NWRN TX AND THIS TREND SHOULD PERSIST FOR THE NEXT FEW HOURS. ISOLATED STORMS MAY BRIEFLY ACHIEVE SEVERE LEVELS AND PRODUCE HAIL AROUND ONE INCH...AND GUSTY WINDS. WHILE STORM COVERAGE WILL CONTINUE TO INCREASE...LATEST INDICATIONS SUGGEST SEVERE POTENTIAL SHOULD REMAIN LIMITED IN TEMPORAL AND AREAL COVERAGE AND A WATCH IS NOT CURRENTLY ANTICIPATED. THE MOST INTENSE CELL AT PRESENT APPEARS TO HAVE FORMED NEAR WEAK WAVE ALONG THE WARM FRONT OVER WILBARGER COUNTY TX. THIS ACTIVITY APPEARS TO BE IN RESPONSE TO FORCING FROM MID LEVEL IMPULSE CROSSING TX PNHDL. MOIST LOW LEVEL INFLOW...MLCAPE AROUND 1000 J/KG...AND EFFECTIVE SHEAR ALONG THE WARM FRONT WILL ALL CONTRIBUTE TO A FAVORABLE SUPERCELL ENVIRONMENT AS THIS STORM MOVES EAST FROM WILBARGER COUNTY TO CLAY COUNTY TX OVER THE NEXT 2 HOURS. INCREASING LARGE SCALE ASCENT ASSOCIATED WITH THE MID LEVEL IMPULSE WILL ALSO PROMOTE TSTM DEVELOPMENT ALONG THE LOW LEVEL WARM CONVEYOR BELT ACROSS NCNTRL TX THIS EVENING. SHEAR AND INSTABILITY WITHIN THIS CORRIDOR ARE FORECAST TO REMAIN MARGINALLY SUPPORTIVE FOR SUPERCELLS. WEAKER MID LEVEL LAPSE RATES AND LIMITED SURFACE-BASED INSTABILITY SHOULD TEMPER A MORE WIDESPREAD CHANCE FOR SEVERE STORMS DESPITE AN EXPECTED INCREASE IN CONVECTION THROUGH THE EVENING HOURS. ..CARBIN.. 11/05/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...TSA...FWD...OUN...SJT...LUB... 32449897 32499971 32570005 32780039 33140036 33560021 34019994 34849945 35119892 35179786 34879699 34429629 33959589 33649578 33409605 33149737 32939811  From mcd at goshenarc.org Mon Nov 6 08:39:09 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 06 Nov 2006 03:39:09 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 060841 SWOMCD SPC MCD 060841 TXZ000-061045- MESOSCALE DISCUSSION 2177 NWS STORM PREDICTION CENTER NORMAN OK 0241 AM CST MON NOV 06 2006 AREAS AFFECTED...SCNTRL TX TO THE MIDDLE TX COAST CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 060841Z - 061045Z ISOLD LARGE HAIL OR DAMAGING WIND GUSTS MAY ACCOMPANY STRONGER TSTMS ACROSS SCNTRL TX THROUGH DAYBREAK. A WATCH IS UNLIKELY GIVEN THE ANTICIPATED SPARSE NATURE TO THE SEVERE THREAT. WATER VAPOR IMAGERY SHOWS A SHORTWAVE TROUGH MOVING ACROSS SCNTRL TX WITH THE STRONGEST H5-H3 QVECTOR CONVERGENCE SHIFTING TO AREAS E OF KDRT TOWARDS THE KSAT AREA. THIS IMPULSE IS EXTRAPOLATED TO THE MIDDLE TX COAST BY MID-MORNING. TSTMS HAVE BEEN INCREASING IN COVERAGE AND INTENSITY DOWNSTREAM ACROSS SCNTRL TX EARLY THIS MORNING. THESE STORMS SHOULD EXPAND/MOVE ACROSS SCNTRL TX INTO AREAS BETWEEN KCRP AND KIAH DURING THE NEXT SEVERAL HOURS. 00Z KDRT AND CURRENT RUC FORECAST SOUNDINGS INDICATE THAT MID-TROPOSPHERIC LAPSE RATES WERE IN EXCESS OF 7.3 DEG C/KM AMIDST CLOUD BEARING SHEAR AOA 55 KTS. THIS WILL BE SUFFICIENT FOR STRONGER UPDRAFTS TO BRIEFLY ORGANIZE WITH ISOLD SUPERCELL STRUCTURES POSSIBLE. GIVEN THE LARGELY STRAIGHT HODOGRAPH IN THE CAPE BEARING LAYER...SPLITTING CELLS WILL BE POSSIBLE...AS ALREADY NOTED NW OF KCOT. THE MAIN SEVERE THREAT WILL BE ISOLD LARGE HAIL...BUT DAMAGING WIND GUSTS ARE ALSO POSSIBLE. ..RACY.. 11/06/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...HGX...CRP...EWX... 29100056 30639873 30349673 29559525 28539527 27949702 28480031  From mcd at goshenarc.org Mon Nov 6 19:39:13 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 06 Nov 2006 14:39:13 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 061941 SWOMCD SPC MCD 061940 ALZ000-MSZ000-LAZ000-062145- MESOSCALE DISCUSSION 2178 NWS STORM PREDICTION CENTER NORMAN OK 0140 PM CST MON NOV 06 2006 AREAS AFFECTED...SE LA...SRN MS CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 061940Z - 062145Z A MARGINAL SEVERE THREAT MAY DEVELOP ACROSS SE LA AND FAR SRN MS OVER THE NEXT FEW HOURS. WIND DAMAGE SHOULD BE THE PRIMARY THREAT ALTHOUGH AN ISOLATED BRIEF TORNADO THREAT MAY EXIST WITH ANY ROTATING STORMS THAT DEVELOP. ALTHOUGH A WW CAN NOT BE RULED OUT...ATTM IT APPEARS THE SEVERE THREAT WILL BE TOO ISOLATED FOR A WW ACROSS THE REGION THIS AFTERNOON. LATEST WATER VAPOR ANALYSIS SHOWS A SHORTWAVE TROUGH/VORTICITY MAX LOCATED ACROSS SW LA. THIS FEATURE IS LOCATED JUST BEHIND A LINE OF THUNDERSTORMS THAT IS CURRENTLY INTENSIFYING AND ORGANIZING ACROSS SRN LA. THE FORCING ASSOCIATED WITH THE VORTICITY MAX SHOULD SUSTAIN THE LINE MOVING INTO SE LA WHERE THE ENVIRONMENT IS WEAKLY UNSTABLE AND SFC DEWPOINTS ARE IN THE MID TO UPPER 60S F. THE LATEST WSR-88D VWPS IN THE NEW ORLEANS AREA SHOW VEERING WINDS WITH HEIGHT BELOW 3 KM WITH OBJECTIVE ANALYSIS SHOWING ABOUT 40 KT AT 500 MB. ALTHOUGH THE SHEAR IS NOT INCREDIBLY STRONG...IT SHOULD BE STRONG ENOUGH FOR A FEW ROTATING STORMS WITH THE BETTER ORGANIZED CELLS EMBEDDED IN THE LINE. AS LOW-LEVEL LAPSE RATES CONTINUE TO STEEPEN OVER THE NEXT FEW HOURS...DAMAGING WIND GUSTS WILL BECOME POSSIBLE...BUT THE WEAK INSTABILITY SUGGESTS THE SEVERE THREAT WILL BE TOO ISOLATED FOR A WW. ..BROYLES.. 11/06/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MOB...JAN...LIX...LCH... 28958910 28919091 29649115 30469061 31079021 31438941 30788822 WWWW From mcd at goshenarc.org Mon Nov 6 19:55:48 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 06 Nov 2006 14:55:48 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 061957 SWOMCD SPC MCD 061956 TXZ000-062100- MESOSCALE DISCUSSION 2179 NWS STORM PREDICTION CENTER NORMAN OK 0156 PM CST MON NOV 06 2006 AREAS AFFECTED...SE TX CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 061956Z - 062100Z A MARGINAL SEVERE THREAT WILL LIKELY CONTINUE TO DEVELOP ACROSS SE TX. HAIL SHOULD BE THE PRIMARY THREAT BUT SHOULD REMAIN ISOLATED. ALTHOUGH A WW CAN NOT BE RULED OUT...A WW APPEARS UNLIKELY ACROSS THE REGION ATTM. LATEST SFC ANALYSIS SHOWS A COLD FRONT EXTENDING SWWD FROM EAST TX INTO THE SRN TX HILL COUNTRY. CONVECTION IS DEVELOPING ALONG THE BOUNDARY WHERE LOW-LEVEL CONVERGENCE IS MAXIMIZED. OTHER STORMS ARE INTENSIFYING ACROSS THE WARM SECTOR AND THIS TREND SHOULD CONTINUE OVER THE NEXT FEW HOURS. ALTHOUGH LOW-LEVEL WINDS ARE VEERING ACROSS THE MID TO UPPER TX COASTAL PLAINS...MODERATE INSTABILITY IS IN PLACE...TEMPS ARE RELATIVELY COLD ALOFT AND MID-LEVEL LAPSE RATES APPEAR STEEP ENOUGH FOR A MARGINAL HAIL THREAT. THE THREAT SHOULD PERSIST FOR A FEW HOURS LATE THIS AFTERNOON AS STORMS MOVE SEWD INTO THE VICTORIA AND PALACIOS AREAS. ..BROYLES.. 11/06/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...HGX...CRP...EWX... 28779604 28469720 29529800 30119731 30459655 30399615 29339543 WWWW From mcd at goshenarc.org Mon Nov 6 19:57:17 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 06 Nov 2006 14:57:17 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 061941 SWOMCD SPC MCD 061940 ALZ000-MSZ000-LAZ000-062145- MESOSCALE DISCUSSION 2178 NWS STORM PREDICTION CENTER NORMAN OK 0140 PM CST MON NOV 06 2006 AREAS AFFECTED...SE LA...SRN MS CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 061940Z - 062145Z A MARGINAL SEVERE THREAT MAY DEVELOP ACROSS SE LA AND FAR SRN MS OVER THE NEXT FEW HOURS. WIND DAMAGE SHOULD BE THE PRIMARY THREAT ALTHOUGH AN ISOLATED BRIEF TORNADO THREAT MAY EXIST WITH ANY ROTATING STORMS THAT DEVELOP. ALTHOUGH A WW CAN NOT BE RULED OUT...ATTM IT APPEARS THE SEVERE THREAT WILL BE TOO ISOLATED FOR A WW ACROSS THE REGION THIS AFTERNOON. LATEST WATER VAPOR ANALYSIS SHOWS A SHORTWAVE TROUGH/VORTICITY MAX LOCATED ACROSS SW LA. THIS FEATURE IS LOCATED JUST BEHIND A LINE OF THUNDERSTORMS THAT IS CURRENTLY INTENSIFYING AND ORGANIZING ACROSS SRN LA. THE FORCING ASSOCIATED WITH THE VORTICITY MAX SHOULD SUSTAIN THE LINE MOVING INTO SE LA WHERE THE ENVIRONMENT IS WEAKLY UNSTABLE AND SFC DEWPOINTS ARE IN THE MID TO UPPER 60S F. THE LATEST WSR-88D VWPS IN THE NEW ORLEANS AREA SHOW VEERING WINDS WITH HEIGHT BELOW 3 KM WITH OBJECTIVE ANALYSIS SHOWING ABOUT 40 KT AT 500 MB. ALTHOUGH THE SHEAR IS NOT INCREDIBLY STRONG...IT SHOULD BE STRONG ENOUGH FOR A FEW ROTATING STORMS WITH THE BETTER ORGANIZED CELLS EMBEDDED IN THE LINE. AS LOW-LEVEL LAPSE RATES CONTINUE TO STEEPEN OVER THE NEXT FEW HOURS...DAMAGING WIND GUSTS WILL BECOME POSSIBLE...BUT THE WEAK INSTABILITY SUGGESTS THE SEVERE THREAT WILL BE TOO ISOLATED FOR A WW. ..BROYLES.. 11/06/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MOB...JAN...LIX...LCH... 28958910 28919091 29649115 30469061 31079021 31438941 30788822  From mcd at goshenarc.org Mon Nov 6 20:02:43 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 06 Nov 2006 15:02:43 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 061957 SWOMCD SPC MCD 061956 TXZ000-062100- MESOSCALE DISCUSSION 2179 NWS STORM PREDICTION CENTER NORMAN OK 0156 PM CST MON NOV 06 2006 AREAS AFFECTED...SE TX CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 061956Z - 062100Z A MARGINAL SEVERE THREAT WILL LIKELY CONTINUE TO DEVELOP ACROSS SE TX. HAIL SHOULD BE THE PRIMARY THREAT BUT SHOULD REMAIN ISOLATED. ALTHOUGH A WW CAN NOT BE RULED OUT...A WW APPEARS UNLIKELY ACROSS THE REGION ATTM. LATEST SFC ANALYSIS SHOWS A COLD FRONT EXTENDING SWWD FROM EAST TX INTO THE SRN TX HILL COUNTRY. CONVECTION IS DEVELOPING ALONG THE BOUNDARY WHERE LOW-LEVEL CONVERGENCE IS MAXIMIZED. OTHER STORMS ARE INTENSIFYING ACROSS THE WARM SECTOR AND THIS TREND SHOULD CONTINUE OVER THE NEXT FEW HOURS. ALTHOUGH LOW-LEVEL WINDS ARE VEERING ACROSS THE MID TO UPPER TX COASTAL PLAINS...MODERATE INSTABILITY IS IN PLACE...TEMPS ARE RELATIVELY COLD ALOFT AND MID-LEVEL LAPSE RATES APPEAR STEEP ENOUGH FOR A MARGINAL HAIL THREAT. THE THREAT SHOULD PERSIST FOR A FEW HOURS LATE THIS AFTERNOON AS STORMS MOVE SEWD INTO THE VICTORIA AND PALACIOS AREAS. ..BROYLES.. 11/06/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...HGX...CRP...EWX... 28779604 28469720 29529800 30119731 30459655 30399615 29339543  From mcd at goshenarc.org Mon Nov 6 22:54:40 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 06 Nov 2006 17:54:40 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 062256 SWOMCD SPC MCD 062256 FLZ000-ALZ000-MSZ000-LAZ000-070030- MESOSCALE DISCUSSION 2180 NWS STORM PREDICTION CENTER NORMAN OK 0456 PM CST MON NOV 06 2006 AREAS AFFECTED...SWRN AL/FAR WRN FL PANHANDLE CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 062256Z - 070030Z THREAT FOR ISOLATED STRONG TO SEVERE STORMS IS EXPECTED TO CONTINUE INTO THE EARLY EVENING AS ACTIVITY MOVES EWD FROM SERN MS/LA INTO SWRN AL AND FAR WRN FL PANHANDLE. IN ADDITION TO HEAVY RAINFALL RATES...THE GREATEST SEVERE THREAT...THOUGH ISOLATED...WILL BE DAMAGING WINDS AND/OR A TORNADO. EXPANSIVE MCS CONTINUES TO SPREAD EWD ACROSS MS/FAR SERN LA...WHILE TIME OF DAY AND DOWNSTREAM CLOUD COVER ARE LIMITING SURFACE HEATING. OBJECTIVE ANALYSES INDICATED MARGINAL INSTABILITY /MLCAPE AOB 500 J/KG/ EXTENDING INTO FAR SWRN AL. DESPITE WEAK INSTABILITY... EFFECTIVE BULK SHEAR /35-45 KT/ AND BACKED LOW LEVEL WINDS ARE SUPPORTING SUPERCELL STRUCTURES AND LOW LEVEL ROTATION SIGNATURES PER REGIONAL RADARS. A FEW SUPERCELLS WILL REMAIN POSSIBLE BOTH ALONG THE LEADING CONVECTIVE LINE AND WITH DISCRETE STORMS DEVELOPING IN SMALL DOWNSTREAM WARM SECTOR. WEAK INSTABILITY IS EXPECTED TO LIMIT THE COVERAGE OF SEVERE STORMS...AND THUS MAKING THE ISSUANCE OF A WATCH UNLIKELY. ..PETERS.. 11/06/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MOB...LIX... 29048947 29988884 30838867 31518868 31588812 31258732 30448675 29808696 28618913  From mcd at goshenarc.org Tue Nov 7 20:16:59 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Tue, 07 Nov 2006 15:16:59 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 072018 SWOMCD SPC MCD 072018 FLZ000-072145- MESOSCALE DISCUSSION 2181 NWS STORM PREDICTION CENTER NORMAN OK 0218 PM CST TUE NOV 07 2006 AREAS AFFECTED...WRN FL PENINSULA CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 072018Z - 072145Z ...STRONG STORMS WILL SPREAD INLAND ACROSS WCNTRL FL PENINSULA SHORTLY... SCATTERED SUPERCELLS HAVE RECENTLY DEVELOPED ALONG TRAILING LINE SEGMENT...ROUGHLY 30SW OF PIE. REGIONAL RADAR DATA CLEARLY DEPICTS MVC MOVING INLAND JUST NORTH OF TPA. ONGOING SUPERCELLS STRUCTURES OFF THE COAST ARE MOST LIKELY ENHANCED BY MORE BUOYANT MARITIME AIRMASS AND SHOULD WEAKEN AS THEY MOVE INLAND. HOWEVER...TRANSITIONAL PHASE FROM HIGHER INSTABILITY OFFSHORE INTO WEAKER INSTABILITY OVER LAND MAY SUPPORT ORGANIZED STRUCTURES CAPABLE OF GENERATING ISOLATED TORNADOES...ESPECIALLY WITH DISCRETE CELLS SOUTH OF ORGANIZED CLUSTER. EXPECTED BREVITY OF SUPERCELL CHARACTERISTICS INLAND WILL PRECLUDE A TORNADO WATCH. ..DARROW.. 11/07/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...TBW... 27488299 28148263 27848220 26908171 26478208  From mcd at goshenarc.org Tue Nov 21 19:51:32 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Tue, 21 Nov 2006 14:51:32 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 211954 SWOMCD SPC MCD 211953 NCZ000-212200- MESOSCALE DISCUSSION 2229 NWS STORM PREDICTION CENTER NORMAN OK 0153 PM CST TUE NOV 21 2006 AREAS AFFECTED...SRN PORTIONS NC OUTER BANKS. CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 211953Z - 212200Z AIR MASS MAY DESTABILIZE SUFFICIENTLY INVOF SFC WARM FRONT TO PERMIT OFFSHORE SVR POTENTIAL TO BRUSH OUTER BANKS FROM CAPE HATTERAS TO CAPE LOOKOUT. STRONG GUSTS AND WATERSPOUTS ARE POSSIBLE OFFSHORE...WITH SMALL BUT NONZERO PROBABILITY THAT SUCH ACTIVITY MAY MOVE ASHORE WHILE STILL SVR...DURING REMAINDER AFTERNOON. AFFECTED LAND AREA WOULD BE TOO SMALL...WITH POTENTIAL CONDITIONAL AND SHORT-LIVED...FOR WW. SFC MESOANALYSIS SHOWS MAIN CYCLONE BECOME MORE VERTICALLY STACKED WITH MID/UPPER LEVEL LOW...AND LOCATED OFFSHORE MOUTH OF ST JOHNS RIVER. OCCLUDED FRONT EXTENDS NEWD TO TRIPLE POINT LOCATED ROUGHLY 60 SE ILM...WITH WARM FRONT NEWD TO ABOUT 15 SE HSE. WARM FRONT IS DRIFTING NWWD AND HAS PASSED BUOY 41025 DURING LAST 1-2 HOURS...WITH SFC THERMAL GRADIENT OF 18 DEG F BETWEEN THOSE STATIONS. STRONGEST PRESSURE FALLS ARE WITHIN COLD AIR INLAND...BENEATH ELEVATED LOW LEVEL WAA REGIME...HOWEVER SECONDARY ISALLOBARIC AXIS EXISTS ALONG FRONT. EXPECT OCCLUSION LOW TO MOVE NEWD ALONG WARM FRONT TOWARD FALL MAX NEAR BUOY 41025...PERHAPS WITH PRIOR DRIFT OF WARM FRONT OVER THIS SECTION OF OUTER BANKS. MODIFIED RAOBS AND RUC SOUNDINGS SUGGEST AIR MASS ALONG AND JUST E OF WARM FRONT IS CHARACTERIZED BY SBCAPES 500-800 J/KG. VERY STRONG LOW LEVEL SHEAR IS EVIDENT BENEATH 50 KT ELY LLJ...LEADING TO 0-1 KM SRH 250-400 J/KG IN SUPPORT OF SVR POTENTIAL FOR ANY TSTMS ALONG WARM FRONT. ACCORDINGLY...SOME SUPERCELL CHARACTERISTICS HAVE BEEN NOTED WITH OFFSHORE TSTMS DURING PAST 2-3 HOURS. WARM SECTOR IS NOT EXPECTED TO PENETRATE INTO INLAND PORTIONS NC GIVEN ISALLOBARICALLY REINFORCED NELYS AND RELATED REINFORCEMENT OF COLD WEDGE W OF FRONT. THEREFORE ANY SVR THREAT SHOULD BE LIMITED TO DISCUSSION AREA. ..EDWARDS.. 11/21/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MHX... 34617658 34977629 35477547 35367538 35087568 34867615 34507656 WWWW From mcd at goshenarc.org Thu Nov 23 08:10:19 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 23 Nov 2006 03:10:19 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 230812 SWOMCD SPC MCD 230812 MAZ000-NHZ000-VTZ000-NYZ000-PAZ000-231215- MESOSCALE DISCUSSION 2230 NWS STORM PREDICTION CENTER NORMAN OK 0212 AM CST THU NOV 23 2006 AREAS AFFECTED...NERN PA...SERN NY...WRN MA CONCERNING...FREEZING RAIN VALID 230812Z - 231215Z AREAS OF LIGHT FREEZING RAIN MAY IMPACT PARTS OF NERN PA...THE MID HUDSON VALLEY...AND NWRN MA THROUGH EARLY TODAY. GENERALLY LIGHT FREEZING PRECIPITATION AMOUNTS OF AROUND 0.01 INCH PER HOUR ARE EXPECTED TO DEVELOP OVER THESE AREAS BETWEEN 09Z AND 12Z. SURFACE WET-BULB 0C ISOTHERM HAS REMAINED ESSENTIALLY STATIONARY ALONG A AVP-POU-BDL LINE THIS MORNING AS LIFT AND MOISTENING TRANSLATE STEADILY NEWD ON THE NOSE OF 40-50KT ELY LLJ. FORECAST SOUNDINGS ACROSS THE REGION SUGGEST THAT THIS PROCESS WILL CONTINUE TO ERODE EXTREMELY DRY SUB-CLOUD AIR MASS WITH EVAPORATIONAL COOLING RESULTING IN THE DEVELOPMENT...OR MAINTENANCE...OF POCKETS OF NEAR FREEZING TEMPERATURES AT THE SURFACE AS PRECIPITATION MOVES NWD. AS DRY LAYERS UNDERGO MOISTENING AND WET-BULB COOLING...A FEW FORECAST SOUNDINGS AND SOME PRECIPITATION-TYPE SCHEMES SUGGEST A LOW PROBABILITY OF LIGHT SNOW REACHING THE SURFACE BEFORE A CHANGEOVER TO LIGHT RA/FZRA. LATEST SREF MEAN GUIDANCE INDICATES A 30-40% PROBABILITY OF FREEZING RAIN RATES AOA 0.05 INCH PER 3 HOURS FROM NERN PA...ACROSS THE SRN CATSKILLS...AND OVER THE MID HUDSON VALLEY TO WRN MA...THROUGH 12Z. THIS FORECAST APPEARS VERY REASONABLE BASED ON LATEST RADAR AND BOUNDARY LAYER TEMPERATURE TRENDS. ..CARBIN.. 11/23/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...BOX...OKX...ALY...PHI...BGM... 42777252 42697206 42277261 42137327 41707429 41237527 41377585 41797569 42337478 42697395 42757333  From mcd at goshenarc.org Mon Nov 27 00:14:27 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Sun, 26 Nov 2006 19:14:27 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 270017 SWOMCD SPC MCD 270016 MNZ000-IAZ000-SDZ000-NEZ000-270515- MESOSCALE DISCUSSION 2231 NWS STORM PREDICTION CENTER NORMAN OK 0616 PM CST SUN NOV 26 2006 AREAS AFFECTED...SERN SD...SWRN MN...NWRN IA...NERN NEB CONCERNING...FREEZING RAIN VALID 270016Z - 270515Z AREAS OF FREEZING RAIN AND PERHAPS SOME SMALL HAIL WILL PERSIST THROUGH AT LEAST 04Z...AND WILL DECREASE FROM W TO EAST THEREAFTER. COLD FRONT CONTINUES TO MOVE SWD WITH TEMPERATURES DROPPING BELOW FREEZING ACROSS THE REGION. ZONE OF WARM ADVECTION PRECIPITATION EXTENDS FROM SERN SD INTO NRN IA NEAR 850MB FRONT AND IS CONVECTIVE WITH NUMEROUS LIGHTNING STRIKES NOTED. APPROACHING SHORTWAVE TROUGH NOW OVER WRN NEB WILL KEEP WINDS JUST ABOVE STABLE SURFACE LAYER RELATIVELY BACKED ACROSS THE REGION...MAINTAINING ZONE OF MOISTURE CONVERGENCE FOR SEVERAL MORE HOURS. FORECAST SOUNDINGS SHOW MUCAPE OF 100-500 J/KG WHICH WHEN COMBINED WITH THE COLD TEMPERATURES ALOFT MAY RESULT IN VERY SMALL HAIL. CONVECTIVELY ENHANCED SHOWERS ALSO SUGGEST LOCALIZED AREAS OF MDT FREEZING RAIN WITH HEAVIEST SHOWERS. PASSAGE OF UPPER SHORTWAVE WILL THEN RESULT IN VEERING LOW LEVEL FLOW AND ADVECTION OF DRIER AIR BETWEEN 04-06Z. ..JEWELL.. 11/27/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MPX...FSD...OAX... 42859599 42579656 42819816 43409813 44129707 44439579 44459481 44269476 43679492 43249536  From mcd at goshenarc.org Wed Nov 29 03:55:43 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Tue, 28 Nov 2006 22:55:43 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 290357 SWOMCD SPC MCD 290357 MOZ000-OKZ000-KSZ000-290600- MESOSCALE DISCUSSION 2232 NWS STORM PREDICTION CENTER NORMAN OK 0957 PM CST TUE NOV 28 2006 AREAS AFFECTED...SERN KS...PARTS OF NE OK AND SW MO CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 290357Z - 290600Z INCREASING THUNDERSTORM ACTIVITY IS EXPECTED WITHIN NEXT FEW HOURS. STRONGER CELLS COULD BRIEFLY BE ACCOMPANIED BY HAIL...PERHAPS GUSTY WINDS...BUT THREAT MAY BE MARGINAL ENOUGH NOT TO REQUIRE A WW. TRENDS WILL BE MONITORED. PRE-FRONTAL SOUTHWESTERLY LOW-LEVEL JET IS STRENGTHENING IN EXCESS OF 40-50 KT ACROSS THE CENTRAL PLAINS. THIS IS ENHANCING LOW-LEVEL WARM ADVECTION ON NOSE OF BETTER LOW-LEVEL GULF MOISTURE RETURN ACROSS NORTHEAST OKLAHOMA INTO SOUTHEASTERN KANSAS...WHERE SATELLITE IMAGERY SUGGESTS A GRADUAL INITIATION OF CONVECTIVE DEVELOPMENT MAY BE UNDERWAY. MID/UPPER FORCING FOR UPWARD VERTICAL MOTION IS WEAK...BUT SLOWLY INCREASING...AHEAD OF VIGOROUS SHORT WAVE TROUGH DIGGING INTO THE CENTRAL ROCKIES. AND...MODELS SUGGEST THUNDERSTORMS COULD DEVELOP NEAR CHANUTE AS EARLY AS 05-06Z...BEFORE INCREASING ACROSS SOUTHEAST KANSAS INTO PARTS OF NORTHEAST OKLAHOMA/SOUTHWEST MISSOURI THROUGH 08-09Z. DEW POINTS NEAR 60F MAY CONTRIBUTE TO MOST UNSTABLE CAPE AS HIGH AS 1000 J/KG ACROSS THIS REGION...IN FAVORABLY SHEARED FLOW REGIME FOR UPDRAFT ROTATION. MARGINALLY SEVERE HAIL APPEARS POSSIBLE IN STRONGEST CELLS. GIVEN UNSATURATED MID-LEVELS...ISOLATED DAMAGING WIND GUSTS MAY ALSO BE POSSIBLE IN STRONGER CELLS BEFORE THEY BECOME UNDERCUT BY SHARP SURFACE COLD FRONT ADVANCING TOWARD THE OZARK PLATEAU. ..KERR.. 11/29/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...SGF...EAX...TSA...TOP...ICT... 37069666 37709625 38369538 38479470 37599440 36689480 36189584 36459664 WWWW From mcd at goshenarc.org Wed Nov 29 10:21:19 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 29 Nov 2006 05:21:19 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 291023 SWOMCD SPC MCD 291022 UTZ000-291415- MESOSCALE DISCUSSION 2233 NWS STORM PREDICTION CENTER NORMAN OK 0422 AM CST WED NOV 29 2006 AREAS AFFECTED...GREAT SALT LAKE/NRN UT CONCERNING...HEAVY SNOW VALID 291022Z - 291415Z LAKE BLOB...WITH INTENSE SNOW RATES OF 1-3 INCHES PER HOUR...WILL SHIFT WWD ACROSS THE NRN SALT LAKE VALLEY INTO THE NRN TOOELE RANGE. VERY STEEP LOW LEVEL LAPSE RATES...ON THE ORDER OF 8 C/KM IN THE CLOUD BEARING LAYER...HAVE CERTAINLY AIDED LAKE EFFECT SNOW THIS MORNING OFF THE SALT LAKE. ALTHOUGH LAKE CONVECTION IS NOT PARTICULARLY BANDED...LIKELY DUE TO SOMEWHAT SHEARED AND WEAK LOW LEVEL FLOW...BROAD ZONE OF INTENSE SNOW SHOULD GRADUALLY SHIFT WWD INTO A MORE N-S ORIENTATION AS MEAN FLOW RESPONDS TO DEEPENING TROUGH OVER THE 4-CORNERS. HEAVIEST ACTIVITY SHOULD SHIFT WEST OF IMMEDIATE SLC AREA...POSSIBLY SPREADING AS FAR WEST AS THE TOOELE VALLEY. WITH TIME...DRYING DUE TO WEAK SUBSIDENCE SHOULD RESULT IN MUCH WEAKER SNOW RATES...POSSIBLY BY 13Z. ..DARROW.. 11/29/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...SLC... 41031251 41061222 40861203 40551189 40421228 40611244 WWWW From mcd at goshenarc.org Wed Nov 29 15:32:13 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 29 Nov 2006 10:32:13 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 291534 SWOMCD SPC MCD 291533 ILZ000-MOZ000-291700- MESOSCALE DISCUSSION 2234 NWS STORM PREDICTION CENTER NORMAN OK 0933 AM CST WED NOV 29 2006 AREAS AFFECTED...SWRN MO NEWD INTO W CENTRAL IL CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE VALID 291533Z - 291700Z THREAT FOR LOCALLY-DAMAGING WINDS APPEARS TO BE INCREASING ATTM AHEAD OF FRONT. WW POSSIBLE IN THE NEXT 1 TO 2 HOURS. LATEST SURFACE ANALYSIS SHOWS COLD FRONT LYING FROM QUINCY IL /UIN/ SWWD TO JUST N OF JOPLIN MO /JLN/. A CONVECTIVE LINE WITH EMBEDDED THUNDERSTORMS CONTINUES ALONG FRONT...WITHIN WEAKLY-UNSTABLE AIRMASS. THOUGH INSTABILITY SHOULD REMAIN MARGINAL WITH DAYTIME HEATING HINDERED TO SOME DEGREE BY CLOUDINESS...500 TO 750 J/KG SURFACE-BASED CAPE IS EXPECTED WITH MID TO UPPER 60S TEMPERATURES AND NEAR 60 DEWPOINTS ACROSS THIS REGION. DESPITE LIMITED INSTABILITY...40 TO 60 KT SWLY FLOW IN THE 850 TO 500 MB LAYER IS RESULTING IN SUFFICIENT SHEAR FOR ORGANIZED/FAST-MOVING STORMS. ONE STORM IN COOPER/MONITEAU COUNTIES IN CENTRAL MO IS NOW EXHIBITING A BOWING STRUCTURE AND IS MOVING ENEWD NEAR 50 KT. GIVEN ADDITIONAL/WEAK DESTABILIZATION...EXPECT POTENTIAL FOR LOCALLY-DAMAGING WINDS TO INCREASE OVER THE NEXT FEW HOURS. ..GOSS.. 11/29/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...ILX...LSX...SGF...EAX... 39579145 40379028 40628892 39468863 38219034 37509168 36639435 37339456 WWWW From mcd at goshenarc.org Wed Nov 29 16:53:34 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 29 Nov 2006 11:53:34 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 291656 SWOMCD SPC MCD 291655 ARZ000-OKZ000-TXZ000-291800- MESOSCALE DISCUSSION 2235 NWS STORM PREDICTION CENTER NORMAN OK 1055 AM CST WED NOV 29 2006 AREAS AFFECTED...PARTS OF N TX NEWD ACROSS SERN OK AND INTO NWRN AR CONCERNING...SEVERE POTENTIAL...WATCH LIKELY VALID 291655Z - 291800Z THUNDERSTORMS ARE FORECAST TO INCREASE ACROSS THIS REGION ALONG FRONT OVER THE NEXT 1 TO 2 HOURS -- LIKELY REQUIRING WW ISSUANCE BY MIDDAY. MOISTURE CONTINUES TO ADVECT NNWWD AHEAD OF COLD FRONT...WITH MID 60S DEWPOINTS NOW EVIDENT FROM SERN OK SWWD INTO PARTS OF CENTRAL AND WRN N TX. THOUGH RUC SOUNDINGS INDICATE THAT AIRMASS REMAINS CAPPED...MODIFYING THESE SOUNDINGS FOR CURRENT SURFACE OBSERVATIONS REVEALS ONLY A WEAK CAPPING INVERSION -- WHICH IS ALSO CONFIRMED BY RECENT DFW ACARS SOUNDINGS. THEREFORE...EXPECT STORMS TO DEVELOP/INCREASE INVOF FRONT ACROSS THE MCD AREA OVER THE NEXT COUPLE OF HOURS. 500 TO 1000 J/KG MEAN-LAYER CAPE IS NOW INDICATED ACROSS THIS REGION AHEAD OF FRONT. WITH JAYTON TX AND PURCELL OK PROFILERS INDICATING SWLY MID-LEVEL FLOW IN EXCESS OF 60 KT ABOVE SSELY SURFACE WINDS...SHEAR SUPPORTIVE OF SEVERE/SUPERCELL STORMS IS IN PLACE. THIS COMBINED WITH DEGREE OF INSTABILITY SUGGESTS A POTENTIAL FOR HAIL AND DAMAGING WINDS ACROSS THE MD AREA. LOW-LEVEL SHEAR ALSO APPEARS TO BE SUFFICIENT GIVEN DEGREE OF INSTABILITY AND LOW LCLS TO SUPPORT A THREAT FOR ISOLATED TORNADOES. ..GOSS.. 11/29/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LZK...SHV...TSA...FWD...OUN...SJT... 34899663 36479462 36229323 33239557 32109820 32300034 34209783  From mcd at goshenarc.org Wed Nov 29 16:57:54 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 29 Nov 2006 11:57:54 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 291700 SWOMCD SPC MCD 291659 IAZ000-MOZ000-KSZ000-NEZ000-OKZ000-292200- MESOSCALE DISCUSSION 2236 NWS STORM PREDICTION CENTER NORMAN OK 1059 AM CST WED NOV 29 2006 AREAS AFFECTED...FAR NORTHEAST OK/EASTERN KS/NORTHWEST MO AND SOUTHWEST/SOUTH CENTRAL IA CONCERNING...WINTER MIXED PRECIPITATION VALID 291659Z - 292200Z FREEZING RAIN AND SLEET WILL STEADILY INCREASE THROUGH EARLY/MID AFTERNOON FROM FAR NORTHEAST OK/EASTERN KS INTO NORTHWEST MO AND SOUTHWEST/SOUTH CENTRAL IA. APPRECIABLE ICE ACCUMULATIONS ARE POSSIBLE BY EARLY EVENING...ESPECIALLY ACROSS EASTERN KS/NORTHWEST MO INCLUDING THE KC METRO AREA. WATER VAPOR IMAGERY/VOLUMETRIC RADAR IMAGERY DEPICTS A RAPID BLOSSOMING OF CONVECTIVE ELEMENTS OVER THE PAST COUPLE OF HOURS FROM NORTH CENTRAL OK INTO EASTERN KS WITHIN THE POST-ARCTIC FRONT REGIME. IN ASSOCIATION WITH THIS TREND...SLEET/FREEZING RAIN HAVE RECENTLY BEEN REPORTED AT CHANUTE KS/BUTLER CO KS/PONCA CITY OK. A SIMILAR TREND IS LIKELY TO EVOLVE/EXPAND NORTHEASTWARD INTO NORTHWEST MO/KC METRO AREA AND SOUTHWEST/SOUTH CENTRAL IA THROUGH MID AFTERNOON...WITH OVERALL PRECIPITATION RATES INCREASING WITHIN THIS CORRIDOR IN PRESENCE OF ELEVATED BAROCLINIC ZONE/WEAK STATIC STABILITY. 12Z TOPEKA KS/ADJUSTED 11Z LAMONT OK OBSERVED RAOBS AND RECENT ACARS SOUNDINGS FROM WICHITA/KANSAS CITY...ALONG WITH REGIONAL PROFILERS...CAPTURE THE 1 KM SUB-FREEZING LAYER IN PLACE FROM NORTH CENTRAL OK TO NORTHEAST KS/NORTHWEST MO. THIS SHALLOW COLD LAYER WILL BE SUPPORTIVE OF FREEZING RAIN AND SLEET WITH INCREASING FORCING FOR ASCENT/SUBSEQUENT MID LEVEL MOISTENING OVER THE NEXT SEVERAL HOURS. GRADUAL ACCUMULATION OF FREEZING RAIN/SLEET WILL LIKELY LEAD TO APPRECIABLE ICE ACCUMULATIONS BY EARLY EVENING...ESPECIALLY ALONG/EAST OF THE KS TURNPIKE TO THE KC METRO AREA AND NORTHWEST MO. ..GUYER.. 11/29/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...SGF...DMX...EAX...TSA...OAX...TOP...ICT...OUN... 40959421 40639282 38979382 37689492 36749594 36619669 36899714 37759731 38879654 39939553  From mcd at goshenarc.org Wed Nov 29 21:04:07 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 29 Nov 2006 16:04:07 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 292106 SWOMCD SPC MCD 292105 ARZ000-OKZ000-TXZ000-292230- MESOSCALE DISCUSSION 2237 NWS STORM PREDICTION CENTER NORMAN OK 0305 PM CST WED NOV 29 2006 AREAS AFFECTED...N TX/PARTS OF CENTRAL AND ERN OK/PORTIONS OF NWRN AR CONCERNING...TORNADO WATCH 869... VALID 292105Z - 292230Z THUNDERSTORMS CONTINUE ACROSS PARTS OF WW 869...WHERE SEVERE THREAT CONTINUES. LATEST RADAR IMAGERY CONTINUES TO SHOW WIDESPREAD THUNDERSTORMS ACROSS ROUGHLY THE WRN HALF OF WW...MAINLY ON AND TO THE COOL SIDE OF THE SURFACE FRONT. MEAN-LAYER CAPE REMAINS FROM ROUGHLY 500 TO NEAR 1000 J/KG ACROSS THAT PORTION OF WW AHEAD OF THE FRONT...WHICH WILL ALLOW AN EWD SPREAD/EXPANSION OF CONVECTION. AREA PROFILERS CONTINUE TO REVEAL STRONG SWLY MID-LEVEL FLOW SUPPORTIVE OF ORGANIZED/SUPERCELL STORMS AND ASSOCIATED POTENTIAL FOR HAIL AND LOCALLY-DAMAGING WINDS. ADDITIONALLY...LATEST DQU /DEQUEEN AR/ PROFILER INDICATES 25 KT 0-1 KM SHEAR...SUPPORTIVE OF A CONTINUED THREAT FOR ISOLATED TORNADOES. ..GOSS.. 11/29/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LZK...SHV...TSA...FWD...OUN...SJT... 35869599 35899354 32299687 32259925 WWWW From mcd at goshenarc.org Wed Nov 29 21:18:05 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 29 Nov 2006 16:18:05 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 292120 SWOMCD SPC MCD 292119 NMZ000-300145- MESOSCALE DISCUSSION 2238 NWS STORM PREDICTION CENTER NORMAN OK 0319 PM CST WED NOV 29 2006 AREAS AFFECTED...NORTHEAST/EAST CENTRAL NM CONCERNING...HEAVY SNOW VALID 292119Z - 300145Z LOCALLY HEAVY SNOW...WITH RATES OF 2 IN/HR POSSIBLE...WILL DEVELOP/SPREAD SOUTHEASTWARD ACROSS EAST CENTRAL NM THROUGH THE REMAINDER OF THE AFTERNOON. VOLUMETRIC RADAR DATA DEPICTS WELL ORGANIZED BAND OF SNOW EXTENDING ACROSS CENTRAL-EASTERN NM...ROUGHLY EITHER SIDE OF I-40 AT MID AFTERNOON. HEAVY SNOW HAS BEEN PREVALENT AT RATON/LAS VEGAS NM ALREADY THIS AFTERNOON...AND MOST RECENTLY AT CLINES CORNERS NM/KCQC. DEVELOPMENT OF LOCALLY HEAVY SNOW APPEARS LIKELY INTO THE TUCUMCARI NM AREA AND OTHER LOCALES ALONG I-40/HIGHWAY 60 THROUGH 00Z AS THE COLD FRONT/DEEP LAYER ASCENT CONTINUES TO SPREAD SOUTHWARD ACROSS NM. LOW TO MID LEVEL FRONTOGENETICAL FORCING...WEAK STATIC STABILITY...AND FAVORABLE NORTHEASTERLY LOW LEVEL UPSLOPE TRAJECTORIES WILL PROMOTE LOCALLY HEAVY SNOW INTO THIS EVENING...WITH 2 IN/HR RATES POSSIBLE WITHIN THE MOST INTENSE SOUTHWEST-NORTHEAST ORIENTED SNOW BANDS. ..GUYER.. 11/29/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...ABQ... 36810433 36700364 36430326 35880321 34730335 34130415 33730529 34210607 35840591 36390537  From mcd at goshenarc.org Wed Nov 29 22:41:28 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 29 Nov 2006 17:41:28 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 292243 SWOMCD SPC MCD 292243 WIZ000-ILZ000-IAZ000-MOZ000-300245- MESOSCALE DISCUSSION 2239 NWS STORM PREDICTION CENTER NORMAN OK 0443 PM CST WED NOV 29 2006 AREAS AFFECTED...NORTHEAST MO/EASTERN IA AND SOUTHWEST WI/NORTHWEST IL CONCERNING...WINTER MIXED PRECIPITATION VALID 292243Z - 300245Z FREEZING RAIN/SLEET WILL STEADILY INCREASE ACROSS EASTERN IA INTO SOUTHWEST WI/NORTHWEST IL THROUGH EARLY/MID EVENING. SOME ICE ACCUMULATION WILL BE POSSIBLE VIA HOURLY LIQUID EQUIVALENT RATES OF 0.05 IN/HR OR GREATER. COINCIDENT WITH PRONOUNCED BAROCLINIC ZONE...CLOUD TOPS CONTINUE TO COOL AND EXPAND INTO THE MIDDLE/UPPER MISSISSIPPI VALLEY PER WATER VAPOR/INFRARED SATELLITE TRENDS. PER RADAR MOSAICS...CONVECTIVE PRECIPITATION ELEMENTS CONTINUE TO SURGE NORTHEASTWARD ACROSS NORTHERN MO INTO EASTERN IA/FAR NORTHWEST IL LATE THIS AFTERNOON...INCLUDING SOME EMBEDDED CLOUD-GROUND LIGHTNING. AS SUGGESTED BY RUC SOUNDINGS AND A RECENT TAMDAR SOUNDING FROM CEDAR RAPIDS IA...THE POST-FRONTAL ENVIRONMENT WITHIN THIS CORRIDOR IS CHARACTERIZED BY AN ELEVATED WARM LAYER ATOP A SHALLOW /APPROX 1 KM/ SUB-FREEZING LAYER. THUS AS PRECIPITATION RATES INCREASE...FREEZING RAIN/SOME SLEET WILL BECOME INCREASINGLY PREVALENT ACROSS FAR EASTERN IA INTO SOUTHWEST WI/NORTHWEST IL THROUGH EARLY/MID EVENING. AIDED BY EMBEDDED CONVECTIVE ELEMENTS...A QUICK CHANGE-OVER TO FREEZING RAIN HAS ALREADY OCCURRED AT KIRKSVILLE MO AND OTTUMWA/CEDAR RAPIDS IA. A SIMILAR TREND IS EXPECTED THROUGH EARLY EVENING INTO THE DUBUQUE AND QUAD CITIES AREAS /PERHAPS BY 01Z-02Z/...WITH THE SURFACE WET BULB ZERO LINE OBSERVED TO BE DEVELOPING EASTWARD AT A RATE OF 50 MILES EVERY 2-3 HOURS. ..GUYER.. 11/29/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LOT...ILX...MKX...LSX...DVN...ARX...DMX...EAX... 40779070 40269169 40159290 40719314 41689256 42809144 43369003 42738898 41758966  From mcd at goshenarc.org Thu Nov 30 00:11:06 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 29 Nov 2006 19:11:06 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 300013 SWOMCD SPC MCD 300012 MOZ000-ARZ000-OKZ000-KSZ000-300515- MESOSCALE DISCUSSION 2240 NWS STORM PREDICTION CENTER NORMAN OK 0612 PM CST WED NOV 29 2006 AREAS AFFECTED...CENTRAL/EASTERN OK AND SOUTHEAST KS/WESTERN MO CONCERNING...WINTER MIXED PRECIPITATION VALID 300012Z - 300515Z SLEET/FREEZING RAIN...AMIDST THUNDER/LIGHTNING...WILL BECOME MORE PREVALENT AND DEVELOP EASTWARD ACROSS EAST CENTRAL OK AND SOUTHWEST/WEST CENTRAL MO THROUGH THE EVENING. SLEET/FREEZING RAIN WILL BECOME INCREASINGLY COMMON ON THE WEST EDGE OF EXISTING SOUTHWEST-NORTHEAST ORIENTED PRECIPITATION BAND ACROSS EASTERN OK INTO FAR SOUTHEAST KS/WESTERN MO...INCLUDING I-40 FROM NEAR/EAST OF THE OKC METRO AREA AND THE I-44 TURNPIKE IN NORTHEAST OK /INCLUDING TULSA/...NORTHEASTWARD TO THE JOPLIN MO AND SEDALIA MO AREAS THROUGH 05Z. AIDED BY CONVECTIVE ELEMENTS VIA CONSIDERABLE ELEVATED INSTABILITY /900 J/KG MUCAPE PER 20Z NORMAN RAOB/...HIGH PRECIPITATION RATES HAS BEEN ENOUGH TO COOL TEMPERATURES TO FREEZING WITH SLEET/FREEZING RAIN. THIS WILL BECOME INCREASINGLY MORE COMMON AS LOW LEVELS CONTINUE TO COOL THIS EVENING...WITH THE SLEET/FREEZING RAIN BECOME MORE WIDESPREAD AS LARGE SCALE ASCENT INCREASES. AS SEEN IN THE 20Z NORMAN OBSERVED SOUNDING AND RECENT ACARS DATA FROM NEAR TULSA...AN UNSTABLE/ELEVATED WARM LAYER ATOP A SHALLOW 1-KM SUB-FREEZING LAYER WITHIN THE POST-SURFACE FRONTAL ENVIRONMENT WILL PROMOTE SLEET/FREEZING RAIN WITH POTENTIAL FOR SOME ICE ACCUMULATION. ..GUYER.. 11/30/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LSX...SGF...EAX...TSA...ICT...OUN... 38859413 39239273 38549270 36989359 35499526 34169702 34119783 34489801 36289682 WWWW From mcd at goshenarc.org Thu Nov 30 00:31:47 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 29 Nov 2006 19:31:47 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 300034 SWOMCD SPC MCD 300033 ARZ000-OKZ000-TXZ000-300130- MESOSCALE DISCUSSION 2241 NWS STORM PREDICTION CENTER NORMAN OK 0633 PM CST WED NOV 29 2006 AREAS AFFECTED...NORTH TX CONCERNING...TORNADO WATCH 869... VALID 300033Z - 300130Z A HAIL THREAT SHOULD PERSIST FOR A FEW MORE HOURS ACROSS SE OK EXTENDING SWWD INTO NCNTRL TX. HOWEVER...THE SEVERE THREAT SHOULD BE TOO ISOLATED TO WARRANT AN EXTENSION OF TORNADO WW 869. A LARGE BAND OF CONVECTION IS ONGOING ALONG AND ABOUT 60 MILES TO THE NORTHWEST OF A COLD FRONT EXTENDING FROM 40 MILES SOUTH OF ABILENE TO NEAR DALLAS AND NORTHEAST TO FORT SMITH AR. A FEW OF THE STORMS MAY HAVE HAIL POTENTIAL FOR ANOTHER HOUR OR SO. ISOLATED STRONG STORMS ARE ALSO DEVELOPING SOUTH OF THE FRONT NEAR WACO. SO FAR...MOST OF THE CONVECTION IS LOCATED ON THE COOL SIDE OF THE FRONT WHERE INSTABILITY IS WEAK. AS FURTHER COOLING OCCURS THIS EVENING...THE SEVERE THREAT SHOULD DIMINISH. THE ONE AREA THAT MAY CONTINUE TO HAVE POTENTIAL FOR HAIL WOULD BE IN THE NRN TX HILL COUNTRY WHERE A SMALL POCKET OF MODERATE INSTABILITY IS PRESENT. ..BROYLES.. 11/30/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LZK...SHV...TSA...FWD...OUN...SJT... 31849731 31489850 31519942 31689966 32169967 32339890 32639819 33869626 34649555 34989508 35079480 34849446 34489437 33569500 32879571 32409630 32209674 WWWW From mcd at goshenarc.org Thu Nov 30 02:46:16 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 29 Nov 2006 21:46:16 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 300248 SWOMCD SPC MCD 300248 TXZ000-300345- MESOSCALE DISCUSSION 2242 NWS STORM PREDICTION CENTER NORMAN OK 0848 PM CST WED NOV 29 2006 AREAS AFFECTED...CNTRL TX CONCERNING...TORNADO WATCH 870... VALID 300248Z - 300345Z AN ISOLATED SUPERCELL IS ONGOING IN CNTRL TX AND OTHER SUPERCELLS MAY INITIATE. AN ISOLATED TORNADO THREAT SHOULD PERSIST FOR SEVERAL MORE HOURS WITH THE ACTIVITY. LATEST SFC ANALYSIS SHOWS A COLD FRONT LOCATED FROM NEAR DALLAS EXTENDING SWWD TO NEAR SAN ANGELO. AN AXIS OF INSTABILITY EXISTS SOUTH OF THE BOUNDARY ACROSS THE TX HILL COUNTRY WHERE MODERATE INSTABILITY IS PRESENT. ISOLATED THUNDERSTORMS ARE ONGOING IN THE WARM SECTOR WELL SOUTH OF THE FRONT. INTENSIFICATION OF THE CELLS MAY OCCUR AS THE LOW-LEVEL JET INCREASES THIS EVENING AND A SHORTWAVE TROUGH EVIDENT ON WATER VAPOR IMAGERY MOVES EWD ACROSS THE REGION. THE STRONG VERTICAL SHEAR SHOWN ON THE LEDBETTER PROFILER WILL SUPPORT SUPERCELLS THAT SHOULD PERSIST FOR SEVERAL MORE HOURS. IN ADDITION...STEEP MID-LEVEL LAPSE RATES SHOULD BE SUFFICIENT FOR HAIL. AN ISOLATED TORNADO THREAT MAY ALSO OCCUR DUE TO THE STRENGTHENING LOW-LEVEL SHEAR. ..BROYLES.. 11/30/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...EWX...SJT... 30149795 29289836 29399946 30139966 30569926 30649874 30579819  From mcd at goshenarc.org Thu Nov 30 04:23:16 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 29 Nov 2006 23:23:16 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 300425 SWOMCD SPC MCD 300425 TXZ000-300630- MESOSCALE DISCUSSION 2243 NWS STORM PREDICTION CENTER NORMAN OK 1025 PM CST WED NOV 29 2006 AREAS AFFECTED...TX PANHANDLE CONCERNING...HEAVY SNOW VALID 300425Z - 300630Z SNOWFALL IS INCREASING ACROSS THE WRN TX PANHANDLE AND THIS TREND SHOULD CONTINUE OVER THE NEXT SEVERAL HOURS. SNOWFALL RATES OF 1 TO 2 INCHES PER HOUR APPEAR LIKELY IN SOME AREAS FOR THE REMAINDER OF THE EVENING. LATEST WATER VAPOR IMAGERY SHOWS AN IMPRESSIVE UPPER-LOW OVER WRN NM. THE UPPER-LOW SHOULD CONTINUE TO DEEPEN AND APPROACH WEST TX TONIGHT. A BAND OF STRONG LARGE-SCALE ASCENT AHEAD OF THE UPPER-LOW IS CURRENTLY MOVING ACROSS THE TX PANHANDLE AND THIS WILL SUPPORT THE ENHANCEMENT OF SNOWFALL. MID-LEVEL FRONTOGENESIS AND STRONG DIFFERENTIAL POSITIVE VORTICITY ADVECTION ALONG WITH STEEP MID-LEVEL LAPSE RATES WILL ENHANCE THE SNOWFALL RATES TO 1 TO 2 INCHES PER HOUR. EXPECT THE BAND OF SNOWFALL THAT CURRENTLY EXTENDS SWWD FROM NEAR AMARILLO TO NEAR MULESHOE TO EXPAND AND MOVE EWD ACROSS THE REMAINDER OF THE TX PANHANDLE. GUSTY NORTHLY WINDS WILL ALSO CREATE BLOWING AND DRIFTING SNOW CONDITIONS. ..BROYLES.. 11/30/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LUB...AMA... 34210128 33930228 34350289 35090281 36250152 36250066 35490015  From mcd at goshenarc.org Thu Nov 30 07:23:48 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 30 Nov 2006 02:23:48 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 300726 SWOMCD SPC MCD 300725 TXZ000-300830- MESOSCALE DISCUSSION 2244 NWS STORM PREDICTION CENTER NORMAN OK 0125 AM CST THU NOV 30 2006 AREAS AFFECTED...CNTRL TX CONCERNING...TORNADO WATCH 870... VALID 300725Z - 300830Z THE THREAT OF SEVERE STORMS APPEARS TO BE DECREASING ACROSS THE REGION AND WW 870 WILL BE ALLOWED TO EXPIRE AT 08Z. AT 07Z...MESOANALYSIS INDICATED ARCTIC COLD FRONT FROM NEAR TYR TO JUST N OF AUS TO NW DRT. SUPERCELL WHICH HAD FORMED EARLIER THIS EVENING HAS SINCE WEAKENED WITH REMNANT CONVECTION EXPECTED TO BE UNDERCUT BY COLD FRONT NEAR AUS BY 08Z. PRE-FRONTAL AIR MASS REMAINS MOIST AND RELATIVELY WARM EARLY THIS MORNING HOWEVER RUC SOUNDINGS INDICATE THAT MID-LEVEL LAPSE RATES ARE QUITE WEAK WHICH IS LIMITING THE DEGREE OF INSTABILITY. WHILE SOME THREAT OF ISOLATED SEVERE STORMS WILL EXIST AHEAD AND/OR ALONG FRONT...THE MARGINAL INSTABILITY SHOULD PRECLUDE A MORE ORGANIZED SEVERE THREAT. ..MEAD.. 11/30/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...FWD...EWX...SJT... 29999990 30539982 31049927 31189873 31179788 30959726 30589701 29999715 29549730 28989810 28919893 28999956  From mcd at goshenarc.org Thu Nov 30 08:42:31 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 30 Nov 2006 03:42:31 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 300844 SWOMCD SPC MCD 300843 OKZ000-KSZ000-TXZ000-301445- MESOSCALE DISCUSSION 2245 NWS STORM PREDICTION CENTER NORMAN OK 0243 AM CST THU NOV 30 2006 AREAS AFFECTED...SRN/CNTRL PLAINS CONCERNING...HEAVY SNOW VALID 300843Z - 301445Z HEAVY SNOW...WITH RATES OF 1-2 INCHES PER HOUR...WILL SPREAD ACROSS THE TX PANHANDLE INTO WRN OK EARLY THIS MORNING. ADDITIONALLY...HEAVY SLEET SHOWERS WILL PRECEED THIS ACTIVITY OVER MUCH OF NWRN TX INTO CNTRL OK...SERN KS. UPPER LOW IS BEGINNING TO DISPLAY A BIT MORE ORGANIZATION OVER THE SRN HIGH PLAINS...PER EXPANDING PRECIPITATION SHIELD OVER THE TX PANHANDLE. IN FACT...LEADING EDGE OF STRONG PVA APPEARS PARTLY RESPONSIBLE FOR LINE OF THUNDERSTORMS THAT STRETCHES FROM MOTLEY COUNTY TX...SWD TO STERLING COUNTY TX. MUCH OF THIS NRN LINE SEGMENT IS LIKELY SNOW...WITH SLEET ASSOCIATED WITH SLY ACTIVITY. LATEST THINKING IS BROAD WARM ADVECTION DOWNSTREAM WILL ENHANCE AN EXPANDING AREA OF HEAVY SLEET SHOWERS FROM NWRN TX...ACROSS CNTRL OK INTO SERN KS. AS THE COLUMN COOLS...SLEET SHOULD CHANGE OVER TO SNOW...INITIALLY ACROSS WRN OK BY 12Z...AND CNTRL SECTIONS AROUND 15-16Z. GREATEST PRECIP RATES...ON THE ORDER OF 1-2 INCHES PER HOUR WILL OCCUR NORTH OF EXPECTED 700MB TRACK...ESSENTIALLY THAT REGION NORTH OF THE RED RIVER. FORECAST SOUNDINGS ALSO INDICATE VERY STEEP LAPSE RATES WILL CONTINUE TO SUPPORT UPRIGHT CONVECTION...FAVORING THE LIKELIHOOD FOR CONTINUED EMBEDDED THUNDER WITH MUCH OF THIS ACTIVITY. ..DARROW.. 11/30/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...TSA...ICT...FWD...OUN...DDC...SJT...LUB...AMA...MAF... 35600099 37629933 37619725 36639607 34779679 32599793 31470111 WWWW From mcd at goshenarc.org Thu Nov 30 12:57:56 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 30 Nov 2006 07:57:56 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 301300 SWOMCD SPC MCD 301259 OKZ000-TXZ000-301700- MESOSCALE DISCUSSION 2246 NWS STORM PREDICTION CENTER NORMAN OK 0659 AM CST THU NOV 30 2006 AREAS AFFECTED...NCNTRL/CNTRL TX CONCERNING...WINTER MIXED PRECIPITATION VALID 301259Z - 301700Z SCATTERED FREEZING RAIN/SLEET SHOWERS ARE EXPECTED TO EXPAND IN AREAL COVERAGE FROM NCNTRL INTO CNTRL TX THIS MORNING. 12Z FWD SOUNDING IS QUITE IMPRESSIVE WITH ELEVATED INSTABILITY...LIFTING A PARCEL NEAR 850MB YIELDS SEVERAL HUNDRED J/KG MUCAPE. LATEST RADAR/LIGHTNING DATA SUPPORT THIS PROFILE WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS FROM JUST N OF DAL...WITH MORE EXTENSIVE CONVECTION FROM SPS...SWD TO NEAR BWD. WRN ACTIVITY IS ALONG LEADING EDGE OF STRONGER PVA...WHICH SHOULD SPREAD INTO NCNTRL/CNTRL TX LATER THIS MORNING. LATEST THINKING IS AREAS WEST OF I-35 SHOULD CONTINUE TO COOL BELOW FREEZING AS SHOWERS INCREASE AHEAD OF MAIN UPPER TROUGH. STRONGER ECHOES COULD PRODUCE LOCALLY HEAVY...BUT BRIEF...FREEZING RAIN/SLEET...ESPECIALLY WITH DEEP CONVECTION/THUNDERSTORMS. ..DARROW.. 11/30/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...FWD...OUN...EWX...SJT... 31059893 32419835 33839701 33699608 32479686 30959748 30529848 WWWW From mcd at goshenarc.org Thu Nov 30 17:16:02 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 30 Nov 2006 12:16:02 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 301718 SWOMCD SPC MCD 301717 OKZ000-KSZ000-302115- MESOSCALE DISCUSSION 2247 NWS STORM PREDICTION CENTER NORMAN OK 1117 AM CST THU NOV 30 2006 AREAS AFFECTED...NORTHERN OK/SOUTHERN KS CONCERNING...HEAVY SNOW VALID 301717Z - 302115Z SNOW WILL LIKELY INTENSIFY ACROSS MUCH OF NORTHERN OK/SOUTH CENTRAL KS THROUGH EARLY AFTERNOON...WITH RATES POTENTIALLY REACHING 1.5-2.0 IN/HR AMIDST GUSTY NORTHERLY WINDS. WATER VAPOR IMAGERY DEPICTS IMPRESSIVE/MATURE CYCLONE CROSSING NORTHWEST TX AT MIDDAY...WITH ASSOCIATED STRONG MID/UPPER JET STREAK OVERSPREADING NORTHERN/CENTRAL TX. ON THE NORTHERN PERIPHERY OF THIS CYCLONE...OBSERVATIONAL TRENDS/NUMERICAL MODEL GUIDANCE SUGGEST HEAVY SNOW WILL INCREASE ACROSS NORTHERN OK/SOUTHERN KS THROUGH EARLY AFTERNOON VIA INCREASING LARGE SCALE LIFT/MESOSCALE PROCESSES WITHIN A FAVORABLE THERMODYNAMIC ENVIRONMENT FOR HEAVY SNOW. AS APPEARS TO ALREADY BE OCCURRING IN AN ENID/PONCA CITY OK TO WICHITA/HUTCHISON KS CORRIDOR PER VOLUMETRIC RADAR IMAGERY AROUND 17Z...WEAK STABILITY/MID LEVEL FRONTOGENETICAL COMPONENT WILL FAVOR THE PREVALENCE OF SOUTHWEST-NORTHEAST ORIENTED SNOW BANDS THROUGH EARLY AFTERNOON ACROSS NORTH CENTRAL OK/SOUTH CENTRAL KS. AFTER A BRIEF LULL THIS MORNING VIA THE ENCROACHING MID LEVEL DRY SLOT...HEAVY SNOW ALSO APPEARS LIKELY TO FILL-IN/INCREASE ACROSS NORTHWEST OK THROUGH EARLY AFTERNOON. CONSIDERABLE EMBEDDED ENHANCEMENT WILL BE POSSIBLE VIA BOTH UPRIGHT AND SLANTWISE CONVECTION PER MODEL SOUNDINGS/EPV DIAGNOSTICS. WITH AN INCREASINGLY DEEP DENDRITIC LAYER AND POTENTIAL FOR MESOSCALE ENHANCEMENT...SNOW RATES MAY REACH 1.5-2.0 IN/HR THIS AFTERNOON. IN ADDITION...GUSTY NORTHERLY WINDS WILL CREATE NEAR-BLIZZARD CONDITIONS AT TIMES...WITH 40 KT WIND SPEEDS IN THE LOWEST 1 KM PER RECENT PROFILER DATA FROM LAMONT OK/VICI OK/HAVILAND KS. ..GUYER.. 11/30/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...TSA...TOP...ICT...OUN...DDC... 38469691 37859574 37289555 36529597 35729876 36369953 37439867  From mcd at goshenarc.org Thu Nov 30 18:03:59 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 30 Nov 2006 13:03:59 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 301806 SWOMCD SPC MCD 301805 INZ000-ILZ000-MOZ000-ARZ000-302230- MESOSCALE DISCUSSION 2248 NWS STORM PREDICTION CENTER NORMAN OK 1205 PM CST THU NOV 30 2006 AREAS AFFECTED...PORTIONS S-CENTRAL MO AND EXTREME NRN AR THROUGH CENTRAL/NERN IL. CONCERNING...FREEZING RAIN VALID 301805Z - 302230Z ONGOING AXIS OF FREEZING RAIN FROM SWRN MO TO CENTRAL IL IS EXPECTED TO REMAIN NEARLY STATIONARY...HOWEVER ACCOMPANYING SWATH OF FREEZING RAIN SHOULD EXPAND LATERALLY -- NWD AND SWD THROUGH MID-AFTERNOON. ADDITIONALLY...FREEZING RAIN MAY DEVELOP NEWD THROUGH BROADER AREA OF CENTRAL/NERN IL BY 21Z. BRIEF/LOCAL PRECIP RATES .25-.5 INCH/HOUR ARE POSSIBLE IN HEAVIER SHOWERS -- AND OVER OZARKS...ISOLATED TSTMS. RATES OF .05-.10 INCH/HOUR SHOULD BECOME MORE COMMON. MAIN SFC CYCLONE IS ANALYZED OVER SWRN AR AND IS BEGINNING TO DEEPEN...WITH INVERTED TROUGH EXTENDING NWWD ACROSS CENTRAL OK. INTENSE SFC FRONT IS ANALYZED FROM AR LOW NEWD ACROSS NWRN TN...THROUGH WEAK MESOLOW OVER SRN INDIANA/NWRN KY. IN BOUNDARY LAYER...BAROCLINIC GRADIENT ASSOCIATED WITH FRONT WILL TIGHTEN AS WEAK SFC DIABATIC HEATING AND SFC WAA OCCUR IN WARM SECTOR...EVAPORATIVE/PRECIP COOLING IN DRY/COLD ADVECTION REGIME CONTINUES N OF FRONT...AND LOW LEVEL FRONTOGENETIC FORCING INTENSIFIES WITH APCH OF STRONG MID-UPPER TROUGH NOW OVER SRN HIGH PLAINS. NET RESULT AT SFC WILL BE GRADUAL SEWD SHIFT OF FREEZING LINE OVER SRN MO AND SRN/ERN IL...LIKEWISE EXPANDING FREEZING RAIN POTENTIAL SEWD. MEANWHILE...ELEVATED WAA/MOISTURE TRANSPORT REGIME WILL INTENSIFY AS SFC CYCLONE DEEPENS OVER AR...AS EVIDENT IN STRENGTHENING OF RUC FCST ISENTROPIC ASCENT IN 297-300K LAYER THROUGH 00Z. THIS SHOULD HELP TO MAINTAIN 150-200 MB DEEP SUPERFREEZING LAYER ALOFT. EXPECT OVERALL EXPANSION/INTENSIFICATION OF RAIN SWATH FROM AR TO INDIANA...NRN PORTION OF WHICH WILL COVER PROGRESSIVELY MORE AREA N OF SFC FREEZING LINE. ..EDWARDS.. 11/30/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...IND...PAH...LOT...ILX...LSX...LZK...SGF...TSA... 40768794 40798761 40758750 40558745 40448748 40198778 38538941 37669016 36669157 36369231 36209280 36039345 36189373 36319389 37839227 38389157 38689119 39838955 40528833  From mcd at goshenarc.org Thu Nov 30 18:59:14 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 30 Nov 2006 13:59:14 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 301901 SWOMCD SPC MCD 301900 TNZ000-MSZ000-ARZ000-LAZ000-302100- MESOSCALE DISCUSSION 2249 NWS STORM PREDICTION CENTER NORMAN OK 0100 PM CST THU NOV 30 2006 AREAS AFFECTED...PORTIONS SRN/CENTRAL/ERN AR...NRN LA...NWRN MS...EXTREME SWRN TN. CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE VALID 301900Z - 302100Z LINE OF SHALLOW CONVECTION NOW EVIDENT INVOF SFC COLD FRONT ACROSS SWRN AR MAY BUILD INTO QUASI-LINEAR CONVECTIVE SYSTEM ACROSS SRN/ERN AR...STRENGTHENING TO SVR LEVELS WITH DAMAGING GUSTS BEING MAIN THREAT. A FEW TORNADOES ALSO ARE POSSIBLE. ACTIVITY MAY AFFECT PORTIONS NRN LA...NERN MS AND PERHAPS EXTREME SWRN TN AS WELL. 18Z SFC MESOANSLYSIS SHOWS DEEPENING SFC LOW BETWEEN HOT-TXK...WHICH SHOULD CONTINUE TO STRENGTHEN AS IT DRIFTS NEWD ROUGHLY ALONG I-30 THEN I-40 TOWARD LIT/MEM AREAS. FRONTAL ZONE E OF THIS LOW HAS SAGGED SWD THROUGH PORTIONS MEM...SGT AND LIT AREAS BUT MAY STALL AND/OR RETREAT SLGTLY N PRIOR TO CYCLONE PASSAGE. THIS FRONT SHOULD MARK SHARP NRN BOUND TO SVR POTENTIAL...GIVEN STRONGLY STABLE SFC AIR TO ITS N AND LACK OF COOLING ALOFT TO SUPPORT HAIL THREAT. BUOYANCY WILL REMAIN MRGL BECAUSE OF MIDLEVEL WARM LAYER -- INDICATED IN RAOBS...ACARS AND MODEL SOUNDINGS. HOWEVER RELATIVELY CLOUD-FREE WARM SECTOR WILL ALLOW CONTINUED SFC HEATING...WEAKENING CINH...AND INCREASING MLCAPES TO AROUND 500 J/KG...BASED ON MODIFIED RUC SOUNDINGS. LOCALIZED SHEAR/VORTICITY ENHANCEMENT IS FCST ALONG FRONT E OF SFC LOW...AND MESOSCALE AND DEEP-LAYER SHEAR PROFILES ARE FCST TO INTENSIFY IN WARM SECTOR AS MID-UPPER CYCLONE EXITS SRN HIGH PLAINS. JUST ABOVE 500 MB...15-18Z WINDS INCREASED FROM 75-100 KT IN FWD RAOBS...A TREND THAT WILL SHIFT ENEWD WITH TIME. STRENGTHENING OF LOW LEVEL WAA REGIME...INTENSIFICATION OF LLJ ABOVE SFC...AND ISALLOBARICALLY FORCED BACKING OF WINDS AHEAD OF SFC LOW...ALL WILL ACT TO ENLARGE WARM SECTOR HODOGRAPHS. EXPECT INCREASINGLY FAVORABLE ENVIRONMENT FOR SUPERCELLS WHERE CONVECTIVE MODE CAN REMAIN RELATIVELY DISCRETE. EMBEDDED SUPERCELLS AND LEWP/BOW CIRCULATIONS ALSO ARE POSSIBLE WITH MAIN CONVECTIVE BAND. ..EDWARDS.. 11/30/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MEG...JAN...LZK...SHV... 32229280 33269281 34259283 34479266 34749214 35029050 35318940 34918910 33359035 32539081 32199134  From mcd at goshenarc.org Thu Nov 30 22:27:04 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 30 Nov 2006 17:27:04 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 302229 SWOMCD SPC MCD 302228 MOZ000-ARZ000-OKZ000-KSZ000-010300- MESOSCALE DISCUSSION 2250 NWS STORM PREDICTION CENTER NORMAN OK 0428 PM CST THU NOV 30 2006 AREAS AFFECTED...NORTHERN/CENTRAL OK AND SOUTH CENTRAL/SOUTHEAST KS INTO WESTERN MO CONCERNING...HEAVY SNOW VALID 302228Z - 010300Z HEAVY SNOW...WITH RATES OF 1-2 IN/HR...WILL CONTINUE/DEVELOP EAST-NORTHEASTWARD ACROSS NORTHERN OK/SOUTHEAST KS...AND BRIEFLY INTO CENTRAL OK...THROUGH EARLY EVENING. SLEET/FREEZING RAIN SHOULD CHANGE OVER TO ALL SNOW ACROSS SOUTHWEST/WEST CENTRAL MO BY 02Z...WITH SNOW BECOMING HEAVY THROUGH MID/LATE EVENING. LATEST WATER VAPOR IMAGERY FEATURES PRONOUNCED DRY SLOT SURGING NORTHEASTWARD ACROSS EASTERN OK AND THE ARKLATEX VICINITY ASSOCIATED WITH CLOSED CYCLONE ACCELERATING NORTHEASTWARD ALONG THE RED RIVER. IN THE NORTHWEST QUADRANT OF THE CYCLONE...OBSERVATIONAL TRENDS COUPLED WITH 15Z SREF AND LATEST RUC/4KM WRF-NMM DETERMINISTIC GUIDANCE SUGGEST THE MOST PROLONGED HEAVY SNOW THROUGH EARLY/MID EVENING WILL BE ACROSS SOUTHEAST KS/NORTHEAST OK...INCLUDING AREAS FROM THE KS TURNPIKE SOUTHEASTWARD TO THE PONCA CITY/TULSA AREAS. AS SEEN THIS AFTERNOON /ESPECIALLY IN SOUTHEAST KS/...MID LEVEL FRONTOGENETICAL FORCING COUPLED WITH NEGATIVE EPV/SLANTWISE INSTABILITY WILL CONTINUE TO PROMOTE THE POTENTIAL FOR ENHANCED SOUTHWEST-NORTHEAST ORIENTED MESOSCALE SNOW BANDS CAPABLE OF RATES TO 2 IN/HR. ACROSS CENTRAL OK...WHILE THE TRAILING PORTION OF THE DEFORMATION BAND SHOULD TEND TO DISSIPATE FROM THE SOUTH/SOUTHWEST THIS EVENING...A BAND OF HEAVY SNOW APPEARS LIKELY TO SPREAD EASTWARD INTO THE OKC METRO AREA BY 00Z. IN ADDITION...STRONG NORTH/NORTHWEST WINDS SEEN IN THE LOWEST FEW KM OF REGIONAL PROFILERS/WSR-88D VWPS WILL PROMOTE CONSIDERABLE BLOWING AND DRIFTING SNOW. FARTHER EAST...OBSERVATIONAL TRENDS AND SHORT-TERM RUC SOUNDINGS SUGGEST SLEET/FREEZING RAIN WILL LIKELY CHANGE OVER TO ALL SNOW ACROSS MUCH OF SOUTHWEST/WEST CENTRAL MO BY 02Z...INCLUDING THE JOPLIN/SPRINGFIELD/SEDALIA/CLINTON AREAS. ..GUYER.. 11/30/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LSX...SGF...EAX...TSA...TOP...ICT...OUN... 39069439 38879280 37739273 36789299 36519336 35949488 35499658 35069745 35379804 36379852 37119805 37829723 38429626  From mcd at goshenarc.org Thu Nov 30 23:25:32 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 30 Nov 2006 18:25:32 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 302327 SWOMCD SPC MCD 302327 ILZ000-MOZ000-010400- MESOSCALE DISCUSSION 2251 NWS STORM PREDICTION CENTER NORMAN OK 0527 PM CST THU NOV 30 2006 AREAS AFFECTED...EAST CENTRAL MO/WEST CENTRAL IL CONCERNING...WINTER MIXED PRECIPITATION VALID 302327Z - 010400Z FREEZING RAIN AND MODERATE/HEAVY SLEET WILL REMAIN PREVALENT ACROSS EAST CENTRAL MO/WEST CENTRAL IL THROUGH MID/LATE EVENING...INCLUDING THE ST LOUIS METRO AREA AND PORTIONS OF I-70/I-44/I-55...WITH ADDITIONAL ICE ACCUMULATIONS VIA LIQUID EQUIVALENTS OF 0.10 IN/HR AND GREATER. WARM CONVEYOR/MOISTURE TRANSPORT REGIME AHEAD OF CYCLONE CURRENTLY CENTERED OVER EASTERN OK WILL CONTINUE TO MAINTAIN AN ELEVATED ABOVE-FREEZING LAYER INTO EAST CENTRAL MO/WEST CENTRAL IL THIS EVENING. THIS IS GENERALLY REPRESENTED BETWEEN 700-850 MB IN RUC POINT SOUNDINGS...SUFFICIENT FOR FULL/PARTIAL MELTING ABOVE A SHALLOW 1-KM SUB-FREEZING LAYER WITH SURFACE TEMPERATURES IN THE 20S. THIS OVERALL SCENARIO IS EXPECTED TO FLUCTUATE LITTLE THIS EVENING...UNTIL THE ARRIVAL OF THE CLOSED LOW/COLDER AIR LATER TONIGHT. WITH CONVECTIVELY ENHANCED ELEMENTS AND DEEP LAYER FORCING FOR ASCENT OVERSPREADING THE REGION...A MIX OF FREEZING RAIN/SLEET WILL REMAIN COMMON THROUGH MID/LATE EVENING IN EAST CENTRAL MO AREAS INCLUDING I-70/I-44 AND COLUMBIA/JEFFERSON CITY/ROLLA/ST LOUIS...AND WEST CENTRAL IL LOCALES INCLUDING QUINCY AND SPRINGFIELD/I-55. ..GUYER.. 11/30/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...ILX...LSX...DVN...SGF... 39349200 39939147 40668982 40278908 39748913 38438978 37419065 37319100 37099169 37469228 38579232  From mcd at goshenarc.org Sun Nov 5 18:21:46 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Sun, 05 Nov 2006 13:21:46 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 051823 SWOMCD SPC MCD 051823 OKZ000-TXZ000-052100- MESOSCALE DISCUSSION 2175 NWS STORM PREDICTION CENTER NORMAN OK 1223 PM CST SUN NOV 05 2006 AREAS AFFECTED...NRN TX AND SRN OK CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE VALID 051823Z - 052100Z TSTMS WITH HAIL MAY INCREASE THROUGH THE AFTERNOON ACROSS PARTS OF THE RED RIVER VALLEY. A WATCH IS POSSIBLE AS VIGOROUS CONVECTION INCREASES OVER THE NEXT FEW HOURS. STRONG VORT MAX WAS EVIDENT IN WATER VAPOR LOOP AND SHORT TERM MODEL GUIDANCE CROSSING THE TX PNHDL ATTM. DPVA AND STEEP LAPSE RATE PLUME ASSOCIATED WITH THIS IMPULSE WERE ACTING IN CONCERT WITH MODEST LOW LEVEL MOISTURE RETURN ACROSS THE SRN PLAINS TO PROVOKE A BAND OF ELEVATED TSTMS FROM WHEELER COUNTY TX TO CUSTER COUNTY OK. MEANWHILE... BREAKS IN CLOUD COVER ACROSS NRN TX AND SWRN OK HAVE ALLOWED BOUNDARY LAYER HEATING AND WEAK WARM SECTOR DEVELOPMENT ACROSS THESE AREAS. VISIBLE SATELLITE IMAGERY WAS SHOWING CU FIELD BECOMING MORE AGITATED ACROSS THIS ZONE AND MLCAPE HAS CLIMBED TO ABOUT 500 J/KG ABOVE WEAKLY CAPPED/STABLE BOUNDARY LAYER AIR MASS. LATEST GUIDANCE CONTINUES TO SUGGEST THAT CONVECTION WILL INCREASE IN COVERAGE THIS AFTERNOON ACROSS THE WARM SECTOR. THIS WILL OCCUR COINCIDENT WITH MAXIMUM IN DIURNAL DESTABILIZATION...AND AS STRONGER DYNAMIC FORCING WITH THE SHORT WAVE TROUGH ACTS ON THE APEX OF LOW LEVEL THETA-E AXIS. SHEAR AND INSTABILITY PARAMETERS SHOULD MARGINALLY SUPPORT SUPERCELL STRUCTURE AND HAIL PRODUCTION FROM A FEW STORMS...ESPECIALLY OVER PARTS OF NORTH TX WITH TIME. EVOLUTION OF THIS SCENARIO WILL CONTINUE TO BE MONITORED AND A SEVERE TSTM WATCH IS POSSIBLE AS THE AFTERNOON PROGRESSES. ..CARBIN.. 11/05/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...TSA...FWD...OUN...LUB...AMA... 33539870 33689928 33780012 33800058 33890084 34120096 34380079 34820032 35000004 35189972 35479906 35439797 34929695 34599598 33809590 33399614 33079690 33359781  From mcd at goshenarc.org Sun Nov 5 21:25:03 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Sun, 05 Nov 2006 16:25:03 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 052127 SWOMCD SPC MCD 052126 OKZ000-TXZ000-052230- MESOSCALE DISCUSSION 2176 NWS STORM PREDICTION CENTER NORMAN OK 0326 PM CST SUN NOV 05 2006 AREAS AFFECTED...SRN OK AND NRN TX CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 052126Z - 052230Z TSTMS CONTINUE TO INCREASE IN COVERAGE ACROSS PARTS OF SWRN OK AND NWRN TX AND THIS TREND SHOULD PERSIST FOR THE NEXT FEW HOURS. ISOLATED STORMS MAY BRIEFLY ACHIEVE SEVERE LEVELS AND PRODUCE HAIL AROUND ONE INCH...AND GUSTY WINDS. WHILE STORM COVERAGE WILL CONTINUE TO INCREASE...LATEST INDICATIONS SUGGEST SEVERE POTENTIAL SHOULD REMAIN LIMITED IN TEMPORAL AND AREAL COVERAGE AND A WATCH IS NOT CURRENTLY ANTICIPATED. THE MOST INTENSE CELL AT PRESENT APPEARS TO HAVE FORMED NEAR WEAK WAVE ALONG THE WARM FRONT OVER WILBARGER COUNTY TX. THIS ACTIVITY APPEARS TO BE IN RESPONSE TO FORCING FROM MID LEVEL IMPULSE CROSSING TX PNHDL. MOIST LOW LEVEL INFLOW...MLCAPE AROUND 1000 J/KG...AND EFFECTIVE SHEAR ALONG THE WARM FRONT WILL ALL CONTRIBUTE TO A FAVORABLE SUPERCELL ENVIRONMENT AS THIS STORM MOVES EAST FROM WILBARGER COUNTY TO CLAY COUNTY TX OVER THE NEXT 2 HOURS. INCREASING LARGE SCALE ASCENT ASSOCIATED WITH THE MID LEVEL IMPULSE WILL ALSO PROMOTE TSTM DEVELOPMENT ALONG THE LOW LEVEL WARM CONVEYOR BELT ACROSS NCNTRL TX THIS EVENING. SHEAR AND INSTABILITY WITHIN THIS CORRIDOR ARE FORECAST TO REMAIN MARGINALLY SUPPORTIVE FOR SUPERCELLS. WEAKER MID LEVEL LAPSE RATES AND LIMITED SURFACE-BASED INSTABILITY SHOULD TEMPER A MORE WIDESPREAD CHANCE FOR SEVERE STORMS DESPITE AN EXPECTED INCREASE IN CONVECTION THROUGH THE EVENING HOURS. ..CARBIN.. 11/05/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...TSA...FWD...OUN...SJT...LUB... 32449897 32499971 32570005 32780039 33140036 33560021 34019994 34849945 35119892 35179786 34879699 34429629 33959589 33649578 33409605 33149737 32939811  From mcd at goshenarc.org Mon Nov 6 08:39:09 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 06 Nov 2006 03:39:09 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 060841 SWOMCD SPC MCD 060841 TXZ000-061045- MESOSCALE DISCUSSION 2177 NWS STORM PREDICTION CENTER NORMAN OK 0241 AM CST MON NOV 06 2006 AREAS AFFECTED...SCNTRL TX TO THE MIDDLE TX COAST CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 060841Z - 061045Z ISOLD LARGE HAIL OR DAMAGING WIND GUSTS MAY ACCOMPANY STRONGER TSTMS ACROSS SCNTRL TX THROUGH DAYBREAK. A WATCH IS UNLIKELY GIVEN THE ANTICIPATED SPARSE NATURE TO THE SEVERE THREAT. WATER VAPOR IMAGERY SHOWS A SHORTWAVE TROUGH MOVING ACROSS SCNTRL TX WITH THE STRONGEST H5-H3 QVECTOR CONVERGENCE SHIFTING TO AREAS E OF KDRT TOWARDS THE KSAT AREA. THIS IMPULSE IS EXTRAPOLATED TO THE MIDDLE TX COAST BY MID-MORNING. TSTMS HAVE BEEN INCREASING IN COVERAGE AND INTENSITY DOWNSTREAM ACROSS SCNTRL TX EARLY THIS MORNING. THESE STORMS SHOULD EXPAND/MOVE ACROSS SCNTRL TX INTO AREAS BETWEEN KCRP AND KIAH DURING THE NEXT SEVERAL HOURS. 00Z KDRT AND CURRENT RUC FORECAST SOUNDINGS INDICATE THAT MID-TROPOSPHERIC LAPSE RATES WERE IN EXCESS OF 7.3 DEG C/KM AMIDST CLOUD BEARING SHEAR AOA 55 KTS. THIS WILL BE SUFFICIENT FOR STRONGER UPDRAFTS TO BRIEFLY ORGANIZE WITH ISOLD SUPERCELL STRUCTURES POSSIBLE. GIVEN THE LARGELY STRAIGHT HODOGRAPH IN THE CAPE BEARING LAYER...SPLITTING CELLS WILL BE POSSIBLE...AS ALREADY NOTED NW OF KCOT. THE MAIN SEVERE THREAT WILL BE ISOLD LARGE HAIL...BUT DAMAGING WIND GUSTS ARE ALSO POSSIBLE. ..RACY.. 11/06/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...HGX...CRP...EWX... 29100056 30639873 30349673 29559525 28539527 27949702 28480031  From mcd at goshenarc.org Mon Nov 6 19:39:13 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 06 Nov 2006 14:39:13 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 061941 SWOMCD SPC MCD 061940 ALZ000-MSZ000-LAZ000-062145- MESOSCALE DISCUSSION 2178 NWS STORM PREDICTION CENTER NORMAN OK 0140 PM CST MON NOV 06 2006 AREAS AFFECTED...SE LA...SRN MS CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 061940Z - 062145Z A MARGINAL SEVERE THREAT MAY DEVELOP ACROSS SE LA AND FAR SRN MS OVER THE NEXT FEW HOURS. WIND DAMAGE SHOULD BE THE PRIMARY THREAT ALTHOUGH AN ISOLATED BRIEF TORNADO THREAT MAY EXIST WITH ANY ROTATING STORMS THAT DEVELOP. ALTHOUGH A WW CAN NOT BE RULED OUT...ATTM IT APPEARS THE SEVERE THREAT WILL BE TOO ISOLATED FOR A WW ACROSS THE REGION THIS AFTERNOON. LATEST WATER VAPOR ANALYSIS SHOWS A SHORTWAVE TROUGH/VORTICITY MAX LOCATED ACROSS SW LA. THIS FEATURE IS LOCATED JUST BEHIND A LINE OF THUNDERSTORMS THAT IS CURRENTLY INTENSIFYING AND ORGANIZING ACROSS SRN LA. THE FORCING ASSOCIATED WITH THE VORTICITY MAX SHOULD SUSTAIN THE LINE MOVING INTO SE LA WHERE THE ENVIRONMENT IS WEAKLY UNSTABLE AND SFC DEWPOINTS ARE IN THE MID TO UPPER 60S F. THE LATEST WSR-88D VWPS IN THE NEW ORLEANS AREA SHOW VEERING WINDS WITH HEIGHT BELOW 3 KM WITH OBJECTIVE ANALYSIS SHOWING ABOUT 40 KT AT 500 MB. ALTHOUGH THE SHEAR IS NOT INCREDIBLY STRONG...IT SHOULD BE STRONG ENOUGH FOR A FEW ROTATING STORMS WITH THE BETTER ORGANIZED CELLS EMBEDDED IN THE LINE. AS LOW-LEVEL LAPSE RATES CONTINUE TO STEEPEN OVER THE NEXT FEW HOURS...DAMAGING WIND GUSTS WILL BECOME POSSIBLE...BUT THE WEAK INSTABILITY SUGGESTS THE SEVERE THREAT WILL BE TOO ISOLATED FOR A WW. ..BROYLES.. 11/06/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MOB...JAN...LIX...LCH... 28958910 28919091 29649115 30469061 31079021 31438941 30788822 WWWW From mcd at goshenarc.org Mon Nov 6 19:55:48 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 06 Nov 2006 14:55:48 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 061957 SWOMCD SPC MCD 061956 TXZ000-062100- MESOSCALE DISCUSSION 2179 NWS STORM PREDICTION CENTER NORMAN OK 0156 PM CST MON NOV 06 2006 AREAS AFFECTED...SE TX CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 061956Z - 062100Z A MARGINAL SEVERE THREAT WILL LIKELY CONTINUE TO DEVELOP ACROSS SE TX. HAIL SHOULD BE THE PRIMARY THREAT BUT SHOULD REMAIN ISOLATED. ALTHOUGH A WW CAN NOT BE RULED OUT...A WW APPEARS UNLIKELY ACROSS THE REGION ATTM. LATEST SFC ANALYSIS SHOWS A COLD FRONT EXTENDING SWWD FROM EAST TX INTO THE SRN TX HILL COUNTRY. CONVECTION IS DEVELOPING ALONG THE BOUNDARY WHERE LOW-LEVEL CONVERGENCE IS MAXIMIZED. OTHER STORMS ARE INTENSIFYING ACROSS THE WARM SECTOR AND THIS TREND SHOULD CONTINUE OVER THE NEXT FEW HOURS. ALTHOUGH LOW-LEVEL WINDS ARE VEERING ACROSS THE MID TO UPPER TX COASTAL PLAINS...MODERATE INSTABILITY IS IN PLACE...TEMPS ARE RELATIVELY COLD ALOFT AND MID-LEVEL LAPSE RATES APPEAR STEEP ENOUGH FOR A MARGINAL HAIL THREAT. THE THREAT SHOULD PERSIST FOR A FEW HOURS LATE THIS AFTERNOON AS STORMS MOVE SEWD INTO THE VICTORIA AND PALACIOS AREAS. ..BROYLES.. 11/06/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...HGX...CRP...EWX... 28779604 28469720 29529800 30119731 30459655 30399615 29339543 WWWW From mcd at goshenarc.org Mon Nov 6 19:57:17 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 06 Nov 2006 14:57:17 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 061941 SWOMCD SPC MCD 061940 ALZ000-MSZ000-LAZ000-062145- MESOSCALE DISCUSSION 2178 NWS STORM PREDICTION CENTER NORMAN OK 0140 PM CST MON NOV 06 2006 AREAS AFFECTED...SE LA...SRN MS CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 061940Z - 062145Z A MARGINAL SEVERE THREAT MAY DEVELOP ACROSS SE LA AND FAR SRN MS OVER THE NEXT FEW HOURS. WIND DAMAGE SHOULD BE THE PRIMARY THREAT ALTHOUGH AN ISOLATED BRIEF TORNADO THREAT MAY EXIST WITH ANY ROTATING STORMS THAT DEVELOP. ALTHOUGH A WW CAN NOT BE RULED OUT...ATTM IT APPEARS THE SEVERE THREAT WILL BE TOO ISOLATED FOR A WW ACROSS THE REGION THIS AFTERNOON. LATEST WATER VAPOR ANALYSIS SHOWS A SHORTWAVE TROUGH/VORTICITY MAX LOCATED ACROSS SW LA. THIS FEATURE IS LOCATED JUST BEHIND A LINE OF THUNDERSTORMS THAT IS CURRENTLY INTENSIFYING AND ORGANIZING ACROSS SRN LA. THE FORCING ASSOCIATED WITH THE VORTICITY MAX SHOULD SUSTAIN THE LINE MOVING INTO SE LA WHERE THE ENVIRONMENT IS WEAKLY UNSTABLE AND SFC DEWPOINTS ARE IN THE MID TO UPPER 60S F. THE LATEST WSR-88D VWPS IN THE NEW ORLEANS AREA SHOW VEERING WINDS WITH HEIGHT BELOW 3 KM WITH OBJECTIVE ANALYSIS SHOWING ABOUT 40 KT AT 500 MB. ALTHOUGH THE SHEAR IS NOT INCREDIBLY STRONG...IT SHOULD BE STRONG ENOUGH FOR A FEW ROTATING STORMS WITH THE BETTER ORGANIZED CELLS EMBEDDED IN THE LINE. AS LOW-LEVEL LAPSE RATES CONTINUE TO STEEPEN OVER THE NEXT FEW HOURS...DAMAGING WIND GUSTS WILL BECOME POSSIBLE...BUT THE WEAK INSTABILITY SUGGESTS THE SEVERE THREAT WILL BE TOO ISOLATED FOR A WW. ..BROYLES.. 11/06/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MOB...JAN...LIX...LCH... 28958910 28919091 29649115 30469061 31079021 31438941 30788822  From mcd at goshenarc.org Mon Nov 6 20:02:43 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 06 Nov 2006 15:02:43 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 061957 SWOMCD SPC MCD 061956 TXZ000-062100- MESOSCALE DISCUSSION 2179 NWS STORM PREDICTION CENTER NORMAN OK 0156 PM CST MON NOV 06 2006 AREAS AFFECTED...SE TX CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 061956Z - 062100Z A MARGINAL SEVERE THREAT WILL LIKELY CONTINUE TO DEVELOP ACROSS SE TX. HAIL SHOULD BE THE PRIMARY THREAT BUT SHOULD REMAIN ISOLATED. ALTHOUGH A WW CAN NOT BE RULED OUT...A WW APPEARS UNLIKELY ACROSS THE REGION ATTM. LATEST SFC ANALYSIS SHOWS A COLD FRONT EXTENDING SWWD FROM EAST TX INTO THE SRN TX HILL COUNTRY. CONVECTION IS DEVELOPING ALONG THE BOUNDARY WHERE LOW-LEVEL CONVERGENCE IS MAXIMIZED. OTHER STORMS ARE INTENSIFYING ACROSS THE WARM SECTOR AND THIS TREND SHOULD CONTINUE OVER THE NEXT FEW HOURS. ALTHOUGH LOW-LEVEL WINDS ARE VEERING ACROSS THE MID TO UPPER TX COASTAL PLAINS...MODERATE INSTABILITY IS IN PLACE...TEMPS ARE RELATIVELY COLD ALOFT AND MID-LEVEL LAPSE RATES APPEAR STEEP ENOUGH FOR A MARGINAL HAIL THREAT. THE THREAT SHOULD PERSIST FOR A FEW HOURS LATE THIS AFTERNOON AS STORMS MOVE SEWD INTO THE VICTORIA AND PALACIOS AREAS. ..BROYLES.. 11/06/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...HGX...CRP...EWX... 28779604 28469720 29529800 30119731 30459655 30399615 29339543  From mcd at goshenarc.org Mon Nov 6 22:54:40 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Mon, 06 Nov 2006 17:54:40 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 062256 SWOMCD SPC MCD 062256 FLZ000-ALZ000-MSZ000-LAZ000-070030- MESOSCALE DISCUSSION 2180 NWS STORM PREDICTION CENTER NORMAN OK 0456 PM CST MON NOV 06 2006 AREAS AFFECTED...SWRN AL/FAR WRN FL PANHANDLE CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 062256Z - 070030Z THREAT FOR ISOLATED STRONG TO SEVERE STORMS IS EXPECTED TO CONTINUE INTO THE EARLY EVENING AS ACTIVITY MOVES EWD FROM SERN MS/LA INTO SWRN AL AND FAR WRN FL PANHANDLE. IN ADDITION TO HEAVY RAINFALL RATES...THE GREATEST SEVERE THREAT...THOUGH ISOLATED...WILL BE DAMAGING WINDS AND/OR A TORNADO. EXPANSIVE MCS CONTINUES TO SPREAD EWD ACROSS MS/FAR SERN LA...WHILE TIME OF DAY AND DOWNSTREAM CLOUD COVER ARE LIMITING SURFACE HEATING. OBJECTIVE ANALYSES INDICATED MARGINAL INSTABILITY /MLCAPE AOB 500 J/KG/ EXTENDING INTO FAR SWRN AL. DESPITE WEAK INSTABILITY... EFFECTIVE BULK SHEAR /35-45 KT/ AND BACKED LOW LEVEL WINDS ARE SUPPORTING SUPERCELL STRUCTURES AND LOW LEVEL ROTATION SIGNATURES PER REGIONAL RADARS. A FEW SUPERCELLS WILL REMAIN POSSIBLE BOTH ALONG THE LEADING CONVECTIVE LINE AND WITH DISCRETE STORMS DEVELOPING IN SMALL DOWNSTREAM WARM SECTOR. WEAK INSTABILITY IS EXPECTED TO LIMIT THE COVERAGE OF SEVERE STORMS...AND THUS MAKING THE ISSUANCE OF A WATCH UNLIKELY. ..PETERS.. 11/06/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MOB...LIX... 29048947 29988884 30838867 31518868 31588812 31258732 30448675 29808696 28618913  From mcd at goshenarc.org Tue Nov 7 20:16:59 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Tue, 07 Nov 2006 15:16:59 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 072018 SWOMCD SPC MCD 072018 FLZ000-072145- MESOSCALE DISCUSSION 2181 NWS STORM PREDICTION CENTER NORMAN OK 0218 PM CST TUE NOV 07 2006 AREAS AFFECTED...WRN FL PENINSULA CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 072018Z - 072145Z ...STRONG STORMS WILL SPREAD INLAND ACROSS WCNTRL FL PENINSULA SHORTLY... SCATTERED SUPERCELLS HAVE RECENTLY DEVELOPED ALONG TRAILING LINE SEGMENT...ROUGHLY 30SW OF PIE. REGIONAL RADAR DATA CLEARLY DEPICTS MVC MOVING INLAND JUST NORTH OF TPA. ONGOING SUPERCELLS STRUCTURES OFF THE COAST ARE MOST LIKELY ENHANCED BY MORE BUOYANT MARITIME AIRMASS AND SHOULD WEAKEN AS THEY MOVE INLAND. HOWEVER...TRANSITIONAL PHASE FROM HIGHER INSTABILITY OFFSHORE INTO WEAKER INSTABILITY OVER LAND MAY SUPPORT ORGANIZED STRUCTURES CAPABLE OF GENERATING ISOLATED TORNADOES...ESPECIALLY WITH DISCRETE CELLS SOUTH OF ORGANIZED CLUSTER. EXPECTED BREVITY OF SUPERCELL CHARACTERISTICS INLAND WILL PRECLUDE A TORNADO WATCH. ..DARROW.. 11/07/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...TBW... 27488299 28148263 27848220 26908171 26478208  From mcd at goshenarc.org Tue Nov 21 19:51:32 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Tue, 21 Nov 2006 14:51:32 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 211954 SWOMCD SPC MCD 211953 NCZ000-212200- MESOSCALE DISCUSSION 2229 NWS STORM PREDICTION CENTER NORMAN OK 0153 PM CST TUE NOV 21 2006 AREAS AFFECTED...SRN PORTIONS NC OUTER BANKS. CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 211953Z - 212200Z AIR MASS MAY DESTABILIZE SUFFICIENTLY INVOF SFC WARM FRONT TO PERMIT OFFSHORE SVR POTENTIAL TO BRUSH OUTER BANKS FROM CAPE HATTERAS TO CAPE LOOKOUT. STRONG GUSTS AND WATERSPOUTS ARE POSSIBLE OFFSHORE...WITH SMALL BUT NONZERO PROBABILITY THAT SUCH ACTIVITY MAY MOVE ASHORE WHILE STILL SVR...DURING REMAINDER AFTERNOON. AFFECTED LAND AREA WOULD BE TOO SMALL...WITH POTENTIAL CONDITIONAL AND SHORT-LIVED...FOR WW. SFC MESOANALYSIS SHOWS MAIN CYCLONE BECOME MORE VERTICALLY STACKED WITH MID/UPPER LEVEL LOW...AND LOCATED OFFSHORE MOUTH OF ST JOHNS RIVER. OCCLUDED FRONT EXTENDS NEWD TO TRIPLE POINT LOCATED ROUGHLY 60 SE ILM...WITH WARM FRONT NEWD TO ABOUT 15 SE HSE. WARM FRONT IS DRIFTING NWWD AND HAS PASSED BUOY 41025 DURING LAST 1-2 HOURS...WITH SFC THERMAL GRADIENT OF 18 DEG F BETWEEN THOSE STATIONS. STRONGEST PRESSURE FALLS ARE WITHIN COLD AIR INLAND...BENEATH ELEVATED LOW LEVEL WAA REGIME...HOWEVER SECONDARY ISALLOBARIC AXIS EXISTS ALONG FRONT. EXPECT OCCLUSION LOW TO MOVE NEWD ALONG WARM FRONT TOWARD FALL MAX NEAR BUOY 41025...PERHAPS WITH PRIOR DRIFT OF WARM FRONT OVER THIS SECTION OF OUTER BANKS. MODIFIED RAOBS AND RUC SOUNDINGS SUGGEST AIR MASS ALONG AND JUST E OF WARM FRONT IS CHARACTERIZED BY SBCAPES 500-800 J/KG. VERY STRONG LOW LEVEL SHEAR IS EVIDENT BENEATH 50 KT ELY LLJ...LEADING TO 0-1 KM SRH 250-400 J/KG IN SUPPORT OF SVR POTENTIAL FOR ANY TSTMS ALONG WARM FRONT. ACCORDINGLY...SOME SUPERCELL CHARACTERISTICS HAVE BEEN NOTED WITH OFFSHORE TSTMS DURING PAST 2-3 HOURS. WARM SECTOR IS NOT EXPECTED TO PENETRATE INTO INLAND PORTIONS NC GIVEN ISALLOBARICALLY REINFORCED NELYS AND RELATED REINFORCEMENT OF COLD WEDGE W OF FRONT. THEREFORE ANY SVR THREAT SHOULD BE LIMITED TO DISCUSSION AREA. ..EDWARDS.. 11/21/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MHX... 34617658 34977629 35477547 35367538 35087568 34867615 34507656 WWWW From mcd at goshenarc.org Thu Nov 23 08:10:19 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 23 Nov 2006 03:10:19 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 230812 SWOMCD SPC MCD 230812 MAZ000-NHZ000-VTZ000-NYZ000-PAZ000-231215- MESOSCALE DISCUSSION 2230 NWS STORM PREDICTION CENTER NORMAN OK 0212 AM CST THU NOV 23 2006 AREAS AFFECTED...NERN PA...SERN NY...WRN MA CONCERNING...FREEZING RAIN VALID 230812Z - 231215Z AREAS OF LIGHT FREEZING RAIN MAY IMPACT PARTS OF NERN PA...THE MID HUDSON VALLEY...AND NWRN MA THROUGH EARLY TODAY. GENERALLY LIGHT FREEZING PRECIPITATION AMOUNTS OF AROUND 0.01 INCH PER HOUR ARE EXPECTED TO DEVELOP OVER THESE AREAS BETWEEN 09Z AND 12Z. SURFACE WET-BULB 0C ISOTHERM HAS REMAINED ESSENTIALLY STATIONARY ALONG A AVP-POU-BDL LINE THIS MORNING AS LIFT AND MOISTENING TRANSLATE STEADILY NEWD ON THE NOSE OF 40-50KT ELY LLJ. FORECAST SOUNDINGS ACROSS THE REGION SUGGEST THAT THIS PROCESS WILL CONTINUE TO ERODE EXTREMELY DRY SUB-CLOUD AIR MASS WITH EVAPORATIONAL COOLING RESULTING IN THE DEVELOPMENT...OR MAINTENANCE...OF POCKETS OF NEAR FREEZING TEMPERATURES AT THE SURFACE AS PRECIPITATION MOVES NWD. AS DRY LAYERS UNDERGO MOISTENING AND WET-BULB COOLING...A FEW FORECAST SOUNDINGS AND SOME PRECIPITATION-TYPE SCHEMES SUGGEST A LOW PROBABILITY OF LIGHT SNOW REACHING THE SURFACE BEFORE A CHANGEOVER TO LIGHT RA/FZRA. LATEST SREF MEAN GUIDANCE INDICATES A 30-40% PROBABILITY OF FREEZING RAIN RATES AOA 0.05 INCH PER 3 HOURS FROM NERN PA...ACROSS THE SRN CATSKILLS...AND OVER THE MID HUDSON VALLEY TO WRN MA...THROUGH 12Z. THIS FORECAST APPEARS VERY REASONABLE BASED ON LATEST RADAR AND BOUNDARY LAYER TEMPERATURE TRENDS. ..CARBIN.. 11/23/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...BOX...OKX...ALY...PHI...BGM... 42777252 42697206 42277261 42137327 41707429 41237527 41377585 41797569 42337478 42697395 42757333  From mcd at goshenarc.org Mon Nov 27 00:14:27 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Sun, 26 Nov 2006 19:14:27 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 270017 SWOMCD SPC MCD 270016 MNZ000-IAZ000-SDZ000-NEZ000-270515- MESOSCALE DISCUSSION 2231 NWS STORM PREDICTION CENTER NORMAN OK 0616 PM CST SUN NOV 26 2006 AREAS AFFECTED...SERN SD...SWRN MN...NWRN IA...NERN NEB CONCERNING...FREEZING RAIN VALID 270016Z - 270515Z AREAS OF FREEZING RAIN AND PERHAPS SOME SMALL HAIL WILL PERSIST THROUGH AT LEAST 04Z...AND WILL DECREASE FROM W TO EAST THEREAFTER. COLD FRONT CONTINUES TO MOVE SWD WITH TEMPERATURES DROPPING BELOW FREEZING ACROSS THE REGION. ZONE OF WARM ADVECTION PRECIPITATION EXTENDS FROM SERN SD INTO NRN IA NEAR 850MB FRONT AND IS CONVECTIVE WITH NUMEROUS LIGHTNING STRIKES NOTED. APPROACHING SHORTWAVE TROUGH NOW OVER WRN NEB WILL KEEP WINDS JUST ABOVE STABLE SURFACE LAYER RELATIVELY BACKED ACROSS THE REGION...MAINTAINING ZONE OF MOISTURE CONVERGENCE FOR SEVERAL MORE HOURS. FORECAST SOUNDINGS SHOW MUCAPE OF 100-500 J/KG WHICH WHEN COMBINED WITH THE COLD TEMPERATURES ALOFT MAY RESULT IN VERY SMALL HAIL. CONVECTIVELY ENHANCED SHOWERS ALSO SUGGEST LOCALIZED AREAS OF MDT FREEZING RAIN WITH HEAVIEST SHOWERS. PASSAGE OF UPPER SHORTWAVE WILL THEN RESULT IN VEERING LOW LEVEL FLOW AND ADVECTION OF DRIER AIR BETWEEN 04-06Z. ..JEWELL.. 11/27/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MPX...FSD...OAX... 42859599 42579656 42819816 43409813 44129707 44439579 44459481 44269476 43679492 43249536  From mcd at goshenarc.org Wed Nov 29 03:55:43 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Tue, 28 Nov 2006 22:55:43 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 290357 SWOMCD SPC MCD 290357 MOZ000-OKZ000-KSZ000-290600- MESOSCALE DISCUSSION 2232 NWS STORM PREDICTION CENTER NORMAN OK 0957 PM CST TUE NOV 28 2006 AREAS AFFECTED...SERN KS...PARTS OF NE OK AND SW MO CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 290357Z - 290600Z INCREASING THUNDERSTORM ACTIVITY IS EXPECTED WITHIN NEXT FEW HOURS. STRONGER CELLS COULD BRIEFLY BE ACCOMPANIED BY HAIL...PERHAPS GUSTY WINDS...BUT THREAT MAY BE MARGINAL ENOUGH NOT TO REQUIRE A WW. TRENDS WILL BE MONITORED. PRE-FRONTAL SOUTHWESTERLY LOW-LEVEL JET IS STRENGTHENING IN EXCESS OF 40-50 KT ACROSS THE CENTRAL PLAINS. THIS IS ENHANCING LOW-LEVEL WARM ADVECTION ON NOSE OF BETTER LOW-LEVEL GULF MOISTURE RETURN ACROSS NORTHEAST OKLAHOMA INTO SOUTHEASTERN KANSAS...WHERE SATELLITE IMAGERY SUGGESTS A GRADUAL INITIATION OF CONVECTIVE DEVELOPMENT MAY BE UNDERWAY. MID/UPPER FORCING FOR UPWARD VERTICAL MOTION IS WEAK...BUT SLOWLY INCREASING...AHEAD OF VIGOROUS SHORT WAVE TROUGH DIGGING INTO THE CENTRAL ROCKIES. AND...MODELS SUGGEST THUNDERSTORMS COULD DEVELOP NEAR CHANUTE AS EARLY AS 05-06Z...BEFORE INCREASING ACROSS SOUTHEAST KANSAS INTO PARTS OF NORTHEAST OKLAHOMA/SOUTHWEST MISSOURI THROUGH 08-09Z. DEW POINTS NEAR 60F MAY CONTRIBUTE TO MOST UNSTABLE CAPE AS HIGH AS 1000 J/KG ACROSS THIS REGION...IN FAVORABLY SHEARED FLOW REGIME FOR UPDRAFT ROTATION. MARGINALLY SEVERE HAIL APPEARS POSSIBLE IN STRONGEST CELLS. GIVEN UNSATURATED MID-LEVELS...ISOLATED DAMAGING WIND GUSTS MAY ALSO BE POSSIBLE IN STRONGER CELLS BEFORE THEY BECOME UNDERCUT BY SHARP SURFACE COLD FRONT ADVANCING TOWARD THE OZARK PLATEAU. ..KERR.. 11/29/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...SGF...EAX...TSA...TOP...ICT... 37069666 37709625 38369538 38479470 37599440 36689480 36189584 36459664 WWWW From mcd at goshenarc.org Wed Nov 29 10:21:19 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 29 Nov 2006 05:21:19 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 291023 SWOMCD SPC MCD 291022 UTZ000-291415- MESOSCALE DISCUSSION 2233 NWS STORM PREDICTION CENTER NORMAN OK 0422 AM CST WED NOV 29 2006 AREAS AFFECTED...GREAT SALT LAKE/NRN UT CONCERNING...HEAVY SNOW VALID 291022Z - 291415Z LAKE BLOB...WITH INTENSE SNOW RATES OF 1-3 INCHES PER HOUR...WILL SHIFT WWD ACROSS THE NRN SALT LAKE VALLEY INTO THE NRN TOOELE RANGE. VERY STEEP LOW LEVEL LAPSE RATES...ON THE ORDER OF 8 C/KM IN THE CLOUD BEARING LAYER...HAVE CERTAINLY AIDED LAKE EFFECT SNOW THIS MORNING OFF THE SALT LAKE. ALTHOUGH LAKE CONVECTION IS NOT PARTICULARLY BANDED...LIKELY DUE TO SOMEWHAT SHEARED AND WEAK LOW LEVEL FLOW...BROAD ZONE OF INTENSE SNOW SHOULD GRADUALLY SHIFT WWD INTO A MORE N-S ORIENTATION AS MEAN FLOW RESPONDS TO DEEPENING TROUGH OVER THE 4-CORNERS. HEAVIEST ACTIVITY SHOULD SHIFT WEST OF IMMEDIATE SLC AREA...POSSIBLY SPREADING AS FAR WEST AS THE TOOELE VALLEY. WITH TIME...DRYING DUE TO WEAK SUBSIDENCE SHOULD RESULT IN MUCH WEAKER SNOW RATES...POSSIBLY BY 13Z. ..DARROW.. 11/29/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...SLC... 41031251 41061222 40861203 40551189 40421228 40611244 WWWW From mcd at goshenarc.org Wed Nov 29 15:32:13 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 29 Nov 2006 10:32:13 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 291534 SWOMCD SPC MCD 291533 ILZ000-MOZ000-291700- MESOSCALE DISCUSSION 2234 NWS STORM PREDICTION CENTER NORMAN OK 0933 AM CST WED NOV 29 2006 AREAS AFFECTED...SWRN MO NEWD INTO W CENTRAL IL CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE VALID 291533Z - 291700Z THREAT FOR LOCALLY-DAMAGING WINDS APPEARS TO BE INCREASING ATTM AHEAD OF FRONT. WW POSSIBLE IN THE NEXT 1 TO 2 HOURS. LATEST SURFACE ANALYSIS SHOWS COLD FRONT LYING FROM QUINCY IL /UIN/ SWWD TO JUST N OF JOPLIN MO /JLN/. A CONVECTIVE LINE WITH EMBEDDED THUNDERSTORMS CONTINUES ALONG FRONT...WITHIN WEAKLY-UNSTABLE AIRMASS. THOUGH INSTABILITY SHOULD REMAIN MARGINAL WITH DAYTIME HEATING HINDERED TO SOME DEGREE BY CLOUDINESS...500 TO 750 J/KG SURFACE-BASED CAPE IS EXPECTED WITH MID TO UPPER 60S TEMPERATURES AND NEAR 60 DEWPOINTS ACROSS THIS REGION. DESPITE LIMITED INSTABILITY...40 TO 60 KT SWLY FLOW IN THE 850 TO 500 MB LAYER IS RESULTING IN SUFFICIENT SHEAR FOR ORGANIZED/FAST-MOVING STORMS. ONE STORM IN COOPER/MONITEAU COUNTIES IN CENTRAL MO IS NOW EXHIBITING A BOWING STRUCTURE AND IS MOVING ENEWD NEAR 50 KT. GIVEN ADDITIONAL/WEAK DESTABILIZATION...EXPECT POTENTIAL FOR LOCALLY-DAMAGING WINDS TO INCREASE OVER THE NEXT FEW HOURS. ..GOSS.. 11/29/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...ILX...LSX...SGF...EAX... 39579145 40379028 40628892 39468863 38219034 37509168 36639435 37339456 WWWW From mcd at goshenarc.org Wed Nov 29 16:53:34 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 29 Nov 2006 11:53:34 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 291656 SWOMCD SPC MCD 291655 ARZ000-OKZ000-TXZ000-291800- MESOSCALE DISCUSSION 2235 NWS STORM PREDICTION CENTER NORMAN OK 1055 AM CST WED NOV 29 2006 AREAS AFFECTED...PARTS OF N TX NEWD ACROSS SERN OK AND INTO NWRN AR CONCERNING...SEVERE POTENTIAL...WATCH LIKELY VALID 291655Z - 291800Z THUNDERSTORMS ARE FORECAST TO INCREASE ACROSS THIS REGION ALONG FRONT OVER THE NEXT 1 TO 2 HOURS -- LIKELY REQUIRING WW ISSUANCE BY MIDDAY. MOISTURE CONTINUES TO ADVECT NNWWD AHEAD OF COLD FRONT...WITH MID 60S DEWPOINTS NOW EVIDENT FROM SERN OK SWWD INTO PARTS OF CENTRAL AND WRN N TX. THOUGH RUC SOUNDINGS INDICATE THAT AIRMASS REMAINS CAPPED...MODIFYING THESE SOUNDINGS FOR CURRENT SURFACE OBSERVATIONS REVEALS ONLY A WEAK CAPPING INVERSION -- WHICH IS ALSO CONFIRMED BY RECENT DFW ACARS SOUNDINGS. THEREFORE...EXPECT STORMS TO DEVELOP/INCREASE INVOF FRONT ACROSS THE MCD AREA OVER THE NEXT COUPLE OF HOURS. 500 TO 1000 J/KG MEAN-LAYER CAPE IS NOW INDICATED ACROSS THIS REGION AHEAD OF FRONT. WITH JAYTON TX AND PURCELL OK PROFILERS INDICATING SWLY MID-LEVEL FLOW IN EXCESS OF 60 KT ABOVE SSELY SURFACE WINDS...SHEAR SUPPORTIVE OF SEVERE/SUPERCELL STORMS IS IN PLACE. THIS COMBINED WITH DEGREE OF INSTABILITY SUGGESTS A POTENTIAL FOR HAIL AND DAMAGING WINDS ACROSS THE MD AREA. LOW-LEVEL SHEAR ALSO APPEARS TO BE SUFFICIENT GIVEN DEGREE OF INSTABILITY AND LOW LCLS TO SUPPORT A THREAT FOR ISOLATED TORNADOES. ..GOSS.. 11/29/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LZK...SHV...TSA...FWD...OUN...SJT... 34899663 36479462 36229323 33239557 32109820 32300034 34209783  From mcd at goshenarc.org Wed Nov 29 16:57:54 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 29 Nov 2006 11:57:54 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 291700 SWOMCD SPC MCD 291659 IAZ000-MOZ000-KSZ000-NEZ000-OKZ000-292200- MESOSCALE DISCUSSION 2236 NWS STORM PREDICTION CENTER NORMAN OK 1059 AM CST WED NOV 29 2006 AREAS AFFECTED...FAR NORTHEAST OK/EASTERN KS/NORTHWEST MO AND SOUTHWEST/SOUTH CENTRAL IA CONCERNING...WINTER MIXED PRECIPITATION VALID 291659Z - 292200Z FREEZING RAIN AND SLEET WILL STEADILY INCREASE THROUGH EARLY/MID AFTERNOON FROM FAR NORTHEAST OK/EASTERN KS INTO NORTHWEST MO AND SOUTHWEST/SOUTH CENTRAL IA. APPRECIABLE ICE ACCUMULATIONS ARE POSSIBLE BY EARLY EVENING...ESPECIALLY ACROSS EASTERN KS/NORTHWEST MO INCLUDING THE KC METRO AREA. WATER VAPOR IMAGERY/VOLUMETRIC RADAR IMAGERY DEPICTS A RAPID BLOSSOMING OF CONVECTIVE ELEMENTS OVER THE PAST COUPLE OF HOURS FROM NORTH CENTRAL OK INTO EASTERN KS WITHIN THE POST-ARCTIC FRONT REGIME. IN ASSOCIATION WITH THIS TREND...SLEET/FREEZING RAIN HAVE RECENTLY BEEN REPORTED AT CHANUTE KS/BUTLER CO KS/PONCA CITY OK. A SIMILAR TREND IS LIKELY TO EVOLVE/EXPAND NORTHEASTWARD INTO NORTHWEST MO/KC METRO AREA AND SOUTHWEST/SOUTH CENTRAL IA THROUGH MID AFTERNOON...WITH OVERALL PRECIPITATION RATES INCREASING WITHIN THIS CORRIDOR IN PRESENCE OF ELEVATED BAROCLINIC ZONE/WEAK STATIC STABILITY. 12Z TOPEKA KS/ADJUSTED 11Z LAMONT OK OBSERVED RAOBS AND RECENT ACARS SOUNDINGS FROM WICHITA/KANSAS CITY...ALONG WITH REGIONAL PROFILERS...CAPTURE THE 1 KM SUB-FREEZING LAYER IN PLACE FROM NORTH CENTRAL OK TO NORTHEAST KS/NORTHWEST MO. THIS SHALLOW COLD LAYER WILL BE SUPPORTIVE OF FREEZING RAIN AND SLEET WITH INCREASING FORCING FOR ASCENT/SUBSEQUENT MID LEVEL MOISTENING OVER THE NEXT SEVERAL HOURS. GRADUAL ACCUMULATION OF FREEZING RAIN/SLEET WILL LIKELY LEAD TO APPRECIABLE ICE ACCUMULATIONS BY EARLY EVENING...ESPECIALLY ALONG/EAST OF THE KS TURNPIKE TO THE KC METRO AREA AND NORTHWEST MO. ..GUYER.. 11/29/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...SGF...DMX...EAX...TSA...OAX...TOP...ICT...OUN... 40959421 40639282 38979382 37689492 36749594 36619669 36899714 37759731 38879654 39939553  From mcd at goshenarc.org Wed Nov 29 21:04:07 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 29 Nov 2006 16:04:07 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 292106 SWOMCD SPC MCD 292105 ARZ000-OKZ000-TXZ000-292230- MESOSCALE DISCUSSION 2237 NWS STORM PREDICTION CENTER NORMAN OK 0305 PM CST WED NOV 29 2006 AREAS AFFECTED...N TX/PARTS OF CENTRAL AND ERN OK/PORTIONS OF NWRN AR CONCERNING...TORNADO WATCH 869... VALID 292105Z - 292230Z THUNDERSTORMS CONTINUE ACROSS PARTS OF WW 869...WHERE SEVERE THREAT CONTINUES. LATEST RADAR IMAGERY CONTINUES TO SHOW WIDESPREAD THUNDERSTORMS ACROSS ROUGHLY THE WRN HALF OF WW...MAINLY ON AND TO THE COOL SIDE OF THE SURFACE FRONT. MEAN-LAYER CAPE REMAINS FROM ROUGHLY 500 TO NEAR 1000 J/KG ACROSS THAT PORTION OF WW AHEAD OF THE FRONT...WHICH WILL ALLOW AN EWD SPREAD/EXPANSION OF CONVECTION. AREA PROFILERS CONTINUE TO REVEAL STRONG SWLY MID-LEVEL FLOW SUPPORTIVE OF ORGANIZED/SUPERCELL STORMS AND ASSOCIATED POTENTIAL FOR HAIL AND LOCALLY-DAMAGING WINDS. ADDITIONALLY...LATEST DQU /DEQUEEN AR/ PROFILER INDICATES 25 KT 0-1 KM SHEAR...SUPPORTIVE OF A CONTINUED THREAT FOR ISOLATED TORNADOES. ..GOSS.. 11/29/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LZK...SHV...TSA...FWD...OUN...SJT... 35869599 35899354 32299687 32259925 WWWW From mcd at goshenarc.org Wed Nov 29 21:18:05 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 29 Nov 2006 16:18:05 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 292120 SWOMCD SPC MCD 292119 NMZ000-300145- MESOSCALE DISCUSSION 2238 NWS STORM PREDICTION CENTER NORMAN OK 0319 PM CST WED NOV 29 2006 AREAS AFFECTED...NORTHEAST/EAST CENTRAL NM CONCERNING...HEAVY SNOW VALID 292119Z - 300145Z LOCALLY HEAVY SNOW...WITH RATES OF 2 IN/HR POSSIBLE...WILL DEVELOP/SPREAD SOUTHEASTWARD ACROSS EAST CENTRAL NM THROUGH THE REMAINDER OF THE AFTERNOON. VOLUMETRIC RADAR DATA DEPICTS WELL ORGANIZED BAND OF SNOW EXTENDING ACROSS CENTRAL-EASTERN NM...ROUGHLY EITHER SIDE OF I-40 AT MID AFTERNOON. HEAVY SNOW HAS BEEN PREVALENT AT RATON/LAS VEGAS NM ALREADY THIS AFTERNOON...AND MOST RECENTLY AT CLINES CORNERS NM/KCQC. DEVELOPMENT OF LOCALLY HEAVY SNOW APPEARS LIKELY INTO THE TUCUMCARI NM AREA AND OTHER LOCALES ALONG I-40/HIGHWAY 60 THROUGH 00Z AS THE COLD FRONT/DEEP LAYER ASCENT CONTINUES TO SPREAD SOUTHWARD ACROSS NM. LOW TO MID LEVEL FRONTOGENETICAL FORCING...WEAK STATIC STABILITY...AND FAVORABLE NORTHEASTERLY LOW LEVEL UPSLOPE TRAJECTORIES WILL PROMOTE LOCALLY HEAVY SNOW INTO THIS EVENING...WITH 2 IN/HR RATES POSSIBLE WITHIN THE MOST INTENSE SOUTHWEST-NORTHEAST ORIENTED SNOW BANDS. ..GUYER.. 11/29/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...ABQ... 36810433 36700364 36430326 35880321 34730335 34130415 33730529 34210607 35840591 36390537  From mcd at goshenarc.org Wed Nov 29 22:41:28 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 29 Nov 2006 17:41:28 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 292243 SWOMCD SPC MCD 292243 WIZ000-ILZ000-IAZ000-MOZ000-300245- MESOSCALE DISCUSSION 2239 NWS STORM PREDICTION CENTER NORMAN OK 0443 PM CST WED NOV 29 2006 AREAS AFFECTED...NORTHEAST MO/EASTERN IA AND SOUTHWEST WI/NORTHWEST IL CONCERNING...WINTER MIXED PRECIPITATION VALID 292243Z - 300245Z FREEZING RAIN/SLEET WILL STEADILY INCREASE ACROSS EASTERN IA INTO SOUTHWEST WI/NORTHWEST IL THROUGH EARLY/MID EVENING. SOME ICE ACCUMULATION WILL BE POSSIBLE VIA HOURLY LIQUID EQUIVALENT RATES OF 0.05 IN/HR OR GREATER. COINCIDENT WITH PRONOUNCED BAROCLINIC ZONE...CLOUD TOPS CONTINUE TO COOL AND EXPAND INTO THE MIDDLE/UPPER MISSISSIPPI VALLEY PER WATER VAPOR/INFRARED SATELLITE TRENDS. PER RADAR MOSAICS...CONVECTIVE PRECIPITATION ELEMENTS CONTINUE TO SURGE NORTHEASTWARD ACROSS NORTHERN MO INTO EASTERN IA/FAR NORTHWEST IL LATE THIS AFTERNOON...INCLUDING SOME EMBEDDED CLOUD-GROUND LIGHTNING. AS SUGGESTED BY RUC SOUNDINGS AND A RECENT TAMDAR SOUNDING FROM CEDAR RAPIDS IA...THE POST-FRONTAL ENVIRONMENT WITHIN THIS CORRIDOR IS CHARACTERIZED BY AN ELEVATED WARM LAYER ATOP A SHALLOW /APPROX 1 KM/ SUB-FREEZING LAYER. THUS AS PRECIPITATION RATES INCREASE...FREEZING RAIN/SOME SLEET WILL BECOME INCREASINGLY PREVALENT ACROSS FAR EASTERN IA INTO SOUTHWEST WI/NORTHWEST IL THROUGH EARLY/MID EVENING. AIDED BY EMBEDDED CONVECTIVE ELEMENTS...A QUICK CHANGE-OVER TO FREEZING RAIN HAS ALREADY OCCURRED AT KIRKSVILLE MO AND OTTUMWA/CEDAR RAPIDS IA. A SIMILAR TREND IS EXPECTED THROUGH EARLY EVENING INTO THE DUBUQUE AND QUAD CITIES AREAS /PERHAPS BY 01Z-02Z/...WITH THE SURFACE WET BULB ZERO LINE OBSERVED TO BE DEVELOPING EASTWARD AT A RATE OF 50 MILES EVERY 2-3 HOURS. ..GUYER.. 11/29/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LOT...ILX...MKX...LSX...DVN...ARX...DMX...EAX... 40779070 40269169 40159290 40719314 41689256 42809144 43369003 42738898 41758966  From mcd at goshenarc.org Thu Nov 30 00:11:06 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 29 Nov 2006 19:11:06 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 300013 SWOMCD SPC MCD 300012 MOZ000-ARZ000-OKZ000-KSZ000-300515- MESOSCALE DISCUSSION 2240 NWS STORM PREDICTION CENTER NORMAN OK 0612 PM CST WED NOV 29 2006 AREAS AFFECTED...CENTRAL/EASTERN OK AND SOUTHEAST KS/WESTERN MO CONCERNING...WINTER MIXED PRECIPITATION VALID 300012Z - 300515Z SLEET/FREEZING RAIN...AMIDST THUNDER/LIGHTNING...WILL BECOME MORE PREVALENT AND DEVELOP EASTWARD ACROSS EAST CENTRAL OK AND SOUTHWEST/WEST CENTRAL MO THROUGH THE EVENING. SLEET/FREEZING RAIN WILL BECOME INCREASINGLY COMMON ON THE WEST EDGE OF EXISTING SOUTHWEST-NORTHEAST ORIENTED PRECIPITATION BAND ACROSS EASTERN OK INTO FAR SOUTHEAST KS/WESTERN MO...INCLUDING I-40 FROM NEAR/EAST OF THE OKC METRO AREA AND THE I-44 TURNPIKE IN NORTHEAST OK /INCLUDING TULSA/...NORTHEASTWARD TO THE JOPLIN MO AND SEDALIA MO AREAS THROUGH 05Z. AIDED BY CONVECTIVE ELEMENTS VIA CONSIDERABLE ELEVATED INSTABILITY /900 J/KG MUCAPE PER 20Z NORMAN RAOB/...HIGH PRECIPITATION RATES HAS BEEN ENOUGH TO COOL TEMPERATURES TO FREEZING WITH SLEET/FREEZING RAIN. THIS WILL BECOME INCREASINGLY MORE COMMON AS LOW LEVELS CONTINUE TO COOL THIS EVENING...WITH THE SLEET/FREEZING RAIN BECOME MORE WIDESPREAD AS LARGE SCALE ASCENT INCREASES. AS SEEN IN THE 20Z NORMAN OBSERVED SOUNDING AND RECENT ACARS DATA FROM NEAR TULSA...AN UNSTABLE/ELEVATED WARM LAYER ATOP A SHALLOW 1-KM SUB-FREEZING LAYER WITHIN THE POST-SURFACE FRONTAL ENVIRONMENT WILL PROMOTE SLEET/FREEZING RAIN WITH POTENTIAL FOR SOME ICE ACCUMULATION. ..GUYER.. 11/30/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LSX...SGF...EAX...TSA...ICT...OUN... 38859413 39239273 38549270 36989359 35499526 34169702 34119783 34489801 36289682 WWWW From mcd at goshenarc.org Thu Nov 30 00:31:47 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 29 Nov 2006 19:31:47 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 300034 SWOMCD SPC MCD 300033 ARZ000-OKZ000-TXZ000-300130- MESOSCALE DISCUSSION 2241 NWS STORM PREDICTION CENTER NORMAN OK 0633 PM CST WED NOV 29 2006 AREAS AFFECTED...NORTH TX CONCERNING...TORNADO WATCH 869... VALID 300033Z - 300130Z A HAIL THREAT SHOULD PERSIST FOR A FEW MORE HOURS ACROSS SE OK EXTENDING SWWD INTO NCNTRL TX. HOWEVER...THE SEVERE THREAT SHOULD BE TOO ISOLATED TO WARRANT AN EXTENSION OF TORNADO WW 869. A LARGE BAND OF CONVECTION IS ONGOING ALONG AND ABOUT 60 MILES TO THE NORTHWEST OF A COLD FRONT EXTENDING FROM 40 MILES SOUTH OF ABILENE TO NEAR DALLAS AND NORTHEAST TO FORT SMITH AR. A FEW OF THE STORMS MAY HAVE HAIL POTENTIAL FOR ANOTHER HOUR OR SO. ISOLATED STRONG STORMS ARE ALSO DEVELOPING SOUTH OF THE FRONT NEAR WACO. SO FAR...MOST OF THE CONVECTION IS LOCATED ON THE COOL SIDE OF THE FRONT WHERE INSTABILITY IS WEAK. AS FURTHER COOLING OCCURS THIS EVENING...THE SEVERE THREAT SHOULD DIMINISH. THE ONE AREA THAT MAY CONTINUE TO HAVE POTENTIAL FOR HAIL WOULD BE IN THE NRN TX HILL COUNTRY WHERE A SMALL POCKET OF MODERATE INSTABILITY IS PRESENT. ..BROYLES.. 11/30/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LZK...SHV...TSA...FWD...OUN...SJT... 31849731 31489850 31519942 31689966 32169967 32339890 32639819 33869626 34649555 34989508 35079480 34849446 34489437 33569500 32879571 32409630 32209674 WWWW From mcd at goshenarc.org Thu Nov 30 02:46:16 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 29 Nov 2006 21:46:16 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 300248 SWOMCD SPC MCD 300248 TXZ000-300345- MESOSCALE DISCUSSION 2242 NWS STORM PREDICTION CENTER NORMAN OK 0848 PM CST WED NOV 29 2006 AREAS AFFECTED...CNTRL TX CONCERNING...TORNADO WATCH 870... VALID 300248Z - 300345Z AN ISOLATED SUPERCELL IS ONGOING IN CNTRL TX AND OTHER SUPERCELLS MAY INITIATE. AN ISOLATED TORNADO THREAT SHOULD PERSIST FOR SEVERAL MORE HOURS WITH THE ACTIVITY. LATEST SFC ANALYSIS SHOWS A COLD FRONT LOCATED FROM NEAR DALLAS EXTENDING SWWD TO NEAR SAN ANGELO. AN AXIS OF INSTABILITY EXISTS SOUTH OF THE BOUNDARY ACROSS THE TX HILL COUNTRY WHERE MODERATE INSTABILITY IS PRESENT. ISOLATED THUNDERSTORMS ARE ONGOING IN THE WARM SECTOR WELL SOUTH OF THE FRONT. INTENSIFICATION OF THE CELLS MAY OCCUR AS THE LOW-LEVEL JET INCREASES THIS EVENING AND A SHORTWAVE TROUGH EVIDENT ON WATER VAPOR IMAGERY MOVES EWD ACROSS THE REGION. THE STRONG VERTICAL SHEAR SHOWN ON THE LEDBETTER PROFILER WILL SUPPORT SUPERCELLS THAT SHOULD PERSIST FOR SEVERAL MORE HOURS. IN ADDITION...STEEP MID-LEVEL LAPSE RATES SHOULD BE SUFFICIENT FOR HAIL. AN ISOLATED TORNADO THREAT MAY ALSO OCCUR DUE TO THE STRENGTHENING LOW-LEVEL SHEAR. ..BROYLES.. 11/30/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...EWX...SJT... 30149795 29289836 29399946 30139966 30569926 30649874 30579819  From mcd at goshenarc.org Thu Nov 30 04:23:16 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Wed, 29 Nov 2006 23:23:16 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 300425 SWOMCD SPC MCD 300425 TXZ000-300630- MESOSCALE DISCUSSION 2243 NWS STORM PREDICTION CENTER NORMAN OK 1025 PM CST WED NOV 29 2006 AREAS AFFECTED...TX PANHANDLE CONCERNING...HEAVY SNOW VALID 300425Z - 300630Z SNOWFALL IS INCREASING ACROSS THE WRN TX PANHANDLE AND THIS TREND SHOULD CONTINUE OVER THE NEXT SEVERAL HOURS. SNOWFALL RATES OF 1 TO 2 INCHES PER HOUR APPEAR LIKELY IN SOME AREAS FOR THE REMAINDER OF THE EVENING. LATEST WATER VAPOR IMAGERY SHOWS AN IMPRESSIVE UPPER-LOW OVER WRN NM. THE UPPER-LOW SHOULD CONTINUE TO DEEPEN AND APPROACH WEST TX TONIGHT. A BAND OF STRONG LARGE-SCALE ASCENT AHEAD OF THE UPPER-LOW IS CURRENTLY MOVING ACROSS THE TX PANHANDLE AND THIS WILL SUPPORT THE ENHANCEMENT OF SNOWFALL. MID-LEVEL FRONTOGENESIS AND STRONG DIFFERENTIAL POSITIVE VORTICITY ADVECTION ALONG WITH STEEP MID-LEVEL LAPSE RATES WILL ENHANCE THE SNOWFALL RATES TO 1 TO 2 INCHES PER HOUR. EXPECT THE BAND OF SNOWFALL THAT CURRENTLY EXTENDS SWWD FROM NEAR AMARILLO TO NEAR MULESHOE TO EXPAND AND MOVE EWD ACROSS THE REMAINDER OF THE TX PANHANDLE. GUSTY NORTHLY WINDS WILL ALSO CREATE BLOWING AND DRIFTING SNOW CONDITIONS. ..BROYLES.. 11/30/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LUB...AMA... 34210128 33930228 34350289 35090281 36250152 36250066 35490015  From mcd at goshenarc.org Thu Nov 30 07:23:48 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 30 Nov 2006 02:23:48 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 300726 SWOMCD SPC MCD 300725 TXZ000-300830- MESOSCALE DISCUSSION 2244 NWS STORM PREDICTION CENTER NORMAN OK 0125 AM CST THU NOV 30 2006 AREAS AFFECTED...CNTRL TX CONCERNING...TORNADO WATCH 870... VALID 300725Z - 300830Z THE THREAT OF SEVERE STORMS APPEARS TO BE DECREASING ACROSS THE REGION AND WW 870 WILL BE ALLOWED TO EXPIRE AT 08Z. AT 07Z...MESOANALYSIS INDICATED ARCTIC COLD FRONT FROM NEAR TYR TO JUST N OF AUS TO NW DRT. SUPERCELL WHICH HAD FORMED EARLIER THIS EVENING HAS SINCE WEAKENED WITH REMNANT CONVECTION EXPECTED TO BE UNDERCUT BY COLD FRONT NEAR AUS BY 08Z. PRE-FRONTAL AIR MASS REMAINS MOIST AND RELATIVELY WARM EARLY THIS MORNING HOWEVER RUC SOUNDINGS INDICATE THAT MID-LEVEL LAPSE RATES ARE QUITE WEAK WHICH IS LIMITING THE DEGREE OF INSTABILITY. WHILE SOME THREAT OF ISOLATED SEVERE STORMS WILL EXIST AHEAD AND/OR ALONG FRONT...THE MARGINAL INSTABILITY SHOULD PRECLUDE A MORE ORGANIZED SEVERE THREAT. ..MEAD.. 11/30/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...FWD...EWX...SJT... 29999990 30539982 31049927 31189873 31179788 30959726 30589701 29999715 29549730 28989810 28919893 28999956  From mcd at goshenarc.org Thu Nov 30 08:42:31 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 30 Nov 2006 03:42:31 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 300844 SWOMCD SPC MCD 300843 OKZ000-KSZ000-TXZ000-301445- MESOSCALE DISCUSSION 2245 NWS STORM PREDICTION CENTER NORMAN OK 0243 AM CST THU NOV 30 2006 AREAS AFFECTED...SRN/CNTRL PLAINS CONCERNING...HEAVY SNOW VALID 300843Z - 301445Z HEAVY SNOW...WITH RATES OF 1-2 INCHES PER HOUR...WILL SPREAD ACROSS THE TX PANHANDLE INTO WRN OK EARLY THIS MORNING. ADDITIONALLY...HEAVY SLEET SHOWERS WILL PRECEED THIS ACTIVITY OVER MUCH OF NWRN TX INTO CNTRL OK...SERN KS. UPPER LOW IS BEGINNING TO DISPLAY A BIT MORE ORGANIZATION OVER THE SRN HIGH PLAINS...PER EXPANDING PRECIPITATION SHIELD OVER THE TX PANHANDLE. IN FACT...LEADING EDGE OF STRONG PVA APPEARS PARTLY RESPONSIBLE FOR LINE OF THUNDERSTORMS THAT STRETCHES FROM MOTLEY COUNTY TX...SWD TO STERLING COUNTY TX. MUCH OF THIS NRN LINE SEGMENT IS LIKELY SNOW...WITH SLEET ASSOCIATED WITH SLY ACTIVITY. LATEST THINKING IS BROAD WARM ADVECTION DOWNSTREAM WILL ENHANCE AN EXPANDING AREA OF HEAVY SLEET SHOWERS FROM NWRN TX...ACROSS CNTRL OK INTO SERN KS. AS THE COLUMN COOLS...SLEET SHOULD CHANGE OVER TO SNOW...INITIALLY ACROSS WRN OK BY 12Z...AND CNTRL SECTIONS AROUND 15-16Z. GREATEST PRECIP RATES...ON THE ORDER OF 1-2 INCHES PER HOUR WILL OCCUR NORTH OF EXPECTED 700MB TRACK...ESSENTIALLY THAT REGION NORTH OF THE RED RIVER. FORECAST SOUNDINGS ALSO INDICATE VERY STEEP LAPSE RATES WILL CONTINUE TO SUPPORT UPRIGHT CONVECTION...FAVORING THE LIKELIHOOD FOR CONTINUED EMBEDDED THUNDER WITH MUCH OF THIS ACTIVITY. ..DARROW.. 11/30/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...TSA...ICT...FWD...OUN...DDC...SJT...LUB...AMA...MAF... 35600099 37629933 37619725 36639607 34779679 32599793 31470111 WWWW From mcd at goshenarc.org Thu Nov 30 12:57:56 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 30 Nov 2006 07:57:56 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 301300 SWOMCD SPC MCD 301259 OKZ000-TXZ000-301700- MESOSCALE DISCUSSION 2246 NWS STORM PREDICTION CENTER NORMAN OK 0659 AM CST THU NOV 30 2006 AREAS AFFECTED...NCNTRL/CNTRL TX CONCERNING...WINTER MIXED PRECIPITATION VALID 301259Z - 301700Z SCATTERED FREEZING RAIN/SLEET SHOWERS ARE EXPECTED TO EXPAND IN AREAL COVERAGE FROM NCNTRL INTO CNTRL TX THIS MORNING. 12Z FWD SOUNDING IS QUITE IMPRESSIVE WITH ELEVATED INSTABILITY...LIFTING A PARCEL NEAR 850MB YIELDS SEVERAL HUNDRED J/KG MUCAPE. LATEST RADAR/LIGHTNING DATA SUPPORT THIS PROFILE WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS FROM JUST N OF DAL...WITH MORE EXTENSIVE CONVECTION FROM SPS...SWD TO NEAR BWD. WRN ACTIVITY IS ALONG LEADING EDGE OF STRONGER PVA...WHICH SHOULD SPREAD INTO NCNTRL/CNTRL TX LATER THIS MORNING. LATEST THINKING IS AREAS WEST OF I-35 SHOULD CONTINUE TO COOL BELOW FREEZING AS SHOWERS INCREASE AHEAD OF MAIN UPPER TROUGH. STRONGER ECHOES COULD PRODUCE LOCALLY HEAVY...BUT BRIEF...FREEZING RAIN/SLEET...ESPECIALLY WITH DEEP CONVECTION/THUNDERSTORMS. ..DARROW.. 11/30/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...FWD...OUN...EWX...SJT... 31059893 32419835 33839701 33699608 32479686 30959748 30529848 WWWW From mcd at goshenarc.org Thu Nov 30 17:16:02 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 30 Nov 2006 12:16:02 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 301718 SWOMCD SPC MCD 301717 OKZ000-KSZ000-302115- MESOSCALE DISCUSSION 2247 NWS STORM PREDICTION CENTER NORMAN OK 1117 AM CST THU NOV 30 2006 AREAS AFFECTED...NORTHERN OK/SOUTHERN KS CONCERNING...HEAVY SNOW VALID 301717Z - 302115Z SNOW WILL LIKELY INTENSIFY ACROSS MUCH OF NORTHERN OK/SOUTH CENTRAL KS THROUGH EARLY AFTERNOON...WITH RATES POTENTIALLY REACHING 1.5-2.0 IN/HR AMIDST GUSTY NORTHERLY WINDS. WATER VAPOR IMAGERY DEPICTS IMPRESSIVE/MATURE CYCLONE CROSSING NORTHWEST TX AT MIDDAY...WITH ASSOCIATED STRONG MID/UPPER JET STREAK OVERSPREADING NORTHERN/CENTRAL TX. ON THE NORTHERN PERIPHERY OF THIS CYCLONE...OBSERVATIONAL TRENDS/NUMERICAL MODEL GUIDANCE SUGGEST HEAVY SNOW WILL INCREASE ACROSS NORTHERN OK/SOUTHERN KS THROUGH EARLY AFTERNOON VIA INCREASING LARGE SCALE LIFT/MESOSCALE PROCESSES WITHIN A FAVORABLE THERMODYNAMIC ENVIRONMENT FOR HEAVY SNOW. AS APPEARS TO ALREADY BE OCCURRING IN AN ENID/PONCA CITY OK TO WICHITA/HUTCHISON KS CORRIDOR PER VOLUMETRIC RADAR IMAGERY AROUND 17Z...WEAK STABILITY/MID LEVEL FRONTOGENETICAL COMPONENT WILL FAVOR THE PREVALENCE OF SOUTHWEST-NORTHEAST ORIENTED SNOW BANDS THROUGH EARLY AFTERNOON ACROSS NORTH CENTRAL OK/SOUTH CENTRAL KS. AFTER A BRIEF LULL THIS MORNING VIA THE ENCROACHING MID LEVEL DRY SLOT...HEAVY SNOW ALSO APPEARS LIKELY TO FILL-IN/INCREASE ACROSS NORTHWEST OK THROUGH EARLY AFTERNOON. CONSIDERABLE EMBEDDED ENHANCEMENT WILL BE POSSIBLE VIA BOTH UPRIGHT AND SLANTWISE CONVECTION PER MODEL SOUNDINGS/EPV DIAGNOSTICS. WITH AN INCREASINGLY DEEP DENDRITIC LAYER AND POTENTIAL FOR MESOSCALE ENHANCEMENT...SNOW RATES MAY REACH 1.5-2.0 IN/HR THIS AFTERNOON. IN ADDITION...GUSTY NORTHERLY WINDS WILL CREATE NEAR-BLIZZARD CONDITIONS AT TIMES...WITH 40 KT WIND SPEEDS IN THE LOWEST 1 KM PER RECENT PROFILER DATA FROM LAMONT OK/VICI OK/HAVILAND KS. ..GUYER.. 11/30/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...TSA...TOP...ICT...OUN...DDC... 38469691 37859574 37289555 36529597 35729876 36369953 37439867  From mcd at goshenarc.org Thu Nov 30 18:03:59 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 30 Nov 2006 13:03:59 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 301806 SWOMCD SPC MCD 301805 INZ000-ILZ000-MOZ000-ARZ000-302230- MESOSCALE DISCUSSION 2248 NWS STORM PREDICTION CENTER NORMAN OK 1205 PM CST THU NOV 30 2006 AREAS AFFECTED...PORTIONS S-CENTRAL MO AND EXTREME NRN AR THROUGH CENTRAL/NERN IL. CONCERNING...FREEZING RAIN VALID 301805Z - 302230Z ONGOING AXIS OF FREEZING RAIN FROM SWRN MO TO CENTRAL IL IS EXPECTED TO REMAIN NEARLY STATIONARY...HOWEVER ACCOMPANYING SWATH OF FREEZING RAIN SHOULD EXPAND LATERALLY -- NWD AND SWD THROUGH MID-AFTERNOON. ADDITIONALLY...FREEZING RAIN MAY DEVELOP NEWD THROUGH BROADER AREA OF CENTRAL/NERN IL BY 21Z. BRIEF/LOCAL PRECIP RATES .25-.5 INCH/HOUR ARE POSSIBLE IN HEAVIER SHOWERS -- AND OVER OZARKS...ISOLATED TSTMS. RATES OF .05-.10 INCH/HOUR SHOULD BECOME MORE COMMON. MAIN SFC CYCLONE IS ANALYZED OVER SWRN AR AND IS BEGINNING TO DEEPEN...WITH INVERTED TROUGH EXTENDING NWWD ACROSS CENTRAL OK. INTENSE SFC FRONT IS ANALYZED FROM AR LOW NEWD ACROSS NWRN TN...THROUGH WEAK MESOLOW OVER SRN INDIANA/NWRN KY. IN BOUNDARY LAYER...BAROCLINIC GRADIENT ASSOCIATED WITH FRONT WILL TIGHTEN AS WEAK SFC DIABATIC HEATING AND SFC WAA OCCUR IN WARM SECTOR...EVAPORATIVE/PRECIP COOLING IN DRY/COLD ADVECTION REGIME CONTINUES N OF FRONT...AND LOW LEVEL FRONTOGENETIC FORCING INTENSIFIES WITH APCH OF STRONG MID-UPPER TROUGH NOW OVER SRN HIGH PLAINS. NET RESULT AT SFC WILL BE GRADUAL SEWD SHIFT OF FREEZING LINE OVER SRN MO AND SRN/ERN IL...LIKEWISE EXPANDING FREEZING RAIN POTENTIAL SEWD. MEANWHILE...ELEVATED WAA/MOISTURE TRANSPORT REGIME WILL INTENSIFY AS SFC CYCLONE DEEPENS OVER AR...AS EVIDENT IN STRENGTHENING OF RUC FCST ISENTROPIC ASCENT IN 297-300K LAYER THROUGH 00Z. THIS SHOULD HELP TO MAINTAIN 150-200 MB DEEP SUPERFREEZING LAYER ALOFT. EXPECT OVERALL EXPANSION/INTENSIFICATION OF RAIN SWATH FROM AR TO INDIANA...NRN PORTION OF WHICH WILL COVER PROGRESSIVELY MORE AREA N OF SFC FREEZING LINE. ..EDWARDS.. 11/30/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...IND...PAH...LOT...ILX...LSX...LZK...SGF...TSA... 40768794 40798761 40758750 40558745 40448748 40198778 38538941 37669016 36669157 36369231 36209280 36039345 36189373 36319389 37839227 38389157 38689119 39838955 40528833  From mcd at goshenarc.org Thu Nov 30 18:59:14 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 30 Nov 2006 13:59:14 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 301901 SWOMCD SPC MCD 301900 TNZ000-MSZ000-ARZ000-LAZ000-302100- MESOSCALE DISCUSSION 2249 NWS STORM PREDICTION CENTER NORMAN OK 0100 PM CST THU NOV 30 2006 AREAS AFFECTED...PORTIONS SRN/CENTRAL/ERN AR...NRN LA...NWRN MS...EXTREME SWRN TN. CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE VALID 301900Z - 302100Z LINE OF SHALLOW CONVECTION NOW EVIDENT INVOF SFC COLD FRONT ACROSS SWRN AR MAY BUILD INTO QUASI-LINEAR CONVECTIVE SYSTEM ACROSS SRN/ERN AR...STRENGTHENING TO SVR LEVELS WITH DAMAGING GUSTS BEING MAIN THREAT. A FEW TORNADOES ALSO ARE POSSIBLE. ACTIVITY MAY AFFECT PORTIONS NRN LA...NERN MS AND PERHAPS EXTREME SWRN TN AS WELL. 18Z SFC MESOANSLYSIS SHOWS DEEPENING SFC LOW BETWEEN HOT-TXK...WHICH SHOULD CONTINUE TO STRENGTHEN AS IT DRIFTS NEWD ROUGHLY ALONG I-30 THEN I-40 TOWARD LIT/MEM AREAS. FRONTAL ZONE E OF THIS LOW HAS SAGGED SWD THROUGH PORTIONS MEM...SGT AND LIT AREAS BUT MAY STALL AND/OR RETREAT SLGTLY N PRIOR TO CYCLONE PASSAGE. THIS FRONT SHOULD MARK SHARP NRN BOUND TO SVR POTENTIAL...GIVEN STRONGLY STABLE SFC AIR TO ITS N AND LACK OF COOLING ALOFT TO SUPPORT HAIL THREAT. BUOYANCY WILL REMAIN MRGL BECAUSE OF MIDLEVEL WARM LAYER -- INDICATED IN RAOBS...ACARS AND MODEL SOUNDINGS. HOWEVER RELATIVELY CLOUD-FREE WARM SECTOR WILL ALLOW CONTINUED SFC HEATING...WEAKENING CINH...AND INCREASING MLCAPES TO AROUND 500 J/KG...BASED ON MODIFIED RUC SOUNDINGS. LOCALIZED SHEAR/VORTICITY ENHANCEMENT IS FCST ALONG FRONT E OF SFC LOW...AND MESOSCALE AND DEEP-LAYER SHEAR PROFILES ARE FCST TO INTENSIFY IN WARM SECTOR AS MID-UPPER CYCLONE EXITS SRN HIGH PLAINS. JUST ABOVE 500 MB...15-18Z WINDS INCREASED FROM 75-100 KT IN FWD RAOBS...A TREND THAT WILL SHIFT ENEWD WITH TIME. STRENGTHENING OF LOW LEVEL WAA REGIME...INTENSIFICATION OF LLJ ABOVE SFC...AND ISALLOBARICALLY FORCED BACKING OF WINDS AHEAD OF SFC LOW...ALL WILL ACT TO ENLARGE WARM SECTOR HODOGRAPHS. EXPECT INCREASINGLY FAVORABLE ENVIRONMENT FOR SUPERCELLS WHERE CONVECTIVE MODE CAN REMAIN RELATIVELY DISCRETE. EMBEDDED SUPERCELLS AND LEWP/BOW CIRCULATIONS ALSO ARE POSSIBLE WITH MAIN CONVECTIVE BAND. ..EDWARDS.. 11/30/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MEG...JAN...LZK...SHV... 32229280 33269281 34259283 34479266 34749214 35029050 35318940 34918910 33359035 32539081 32199134  From mcd at goshenarc.org Thu Nov 30 22:27:04 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 30 Nov 2006 17:27:04 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 302229 SWOMCD SPC MCD 302228 MOZ000-ARZ000-OKZ000-KSZ000-010300- MESOSCALE DISCUSSION 2250 NWS STORM PREDICTION CENTER NORMAN OK 0428 PM CST THU NOV 30 2006 AREAS AFFECTED...NORTHERN/CENTRAL OK AND SOUTH CENTRAL/SOUTHEAST KS INTO WESTERN MO CONCERNING...HEAVY SNOW VALID 302228Z - 010300Z HEAVY SNOW...WITH RATES OF 1-2 IN/HR...WILL CONTINUE/DEVELOP EAST-NORTHEASTWARD ACROSS NORTHERN OK/SOUTHEAST KS...AND BRIEFLY INTO CENTRAL OK...THROUGH EARLY EVENING. SLEET/FREEZING RAIN SHOULD CHANGE OVER TO ALL SNOW ACROSS SOUTHWEST/WEST CENTRAL MO BY 02Z...WITH SNOW BECOMING HEAVY THROUGH MID/LATE EVENING. LATEST WATER VAPOR IMAGERY FEATURES PRONOUNCED DRY SLOT SURGING NORTHEASTWARD ACROSS EASTERN OK AND THE ARKLATEX VICINITY ASSOCIATED WITH CLOSED CYCLONE ACCELERATING NORTHEASTWARD ALONG THE RED RIVER. IN THE NORTHWEST QUADRANT OF THE CYCLONE...OBSERVATIONAL TRENDS COUPLED WITH 15Z SREF AND LATEST RUC/4KM WRF-NMM DETERMINISTIC GUIDANCE SUGGEST THE MOST PROLONGED HEAVY SNOW THROUGH EARLY/MID EVENING WILL BE ACROSS SOUTHEAST KS/NORTHEAST OK...INCLUDING AREAS FROM THE KS TURNPIKE SOUTHEASTWARD TO THE PONCA CITY/TULSA AREAS. AS SEEN THIS AFTERNOON /ESPECIALLY IN SOUTHEAST KS/...MID LEVEL FRONTOGENETICAL FORCING COUPLED WITH NEGATIVE EPV/SLANTWISE INSTABILITY WILL CONTINUE TO PROMOTE THE POTENTIAL FOR ENHANCED SOUTHWEST-NORTHEAST ORIENTED MESOSCALE SNOW BANDS CAPABLE OF RATES TO 2 IN/HR. ACROSS CENTRAL OK...WHILE THE TRAILING PORTION OF THE DEFORMATION BAND SHOULD TEND TO DISSIPATE FROM THE SOUTH/SOUTHWEST THIS EVENING...A BAND OF HEAVY SNOW APPEARS LIKELY TO SPREAD EASTWARD INTO THE OKC METRO AREA BY 00Z. IN ADDITION...STRONG NORTH/NORTHWEST WINDS SEEN IN THE LOWEST FEW KM OF REGIONAL PROFILERS/WSR-88D VWPS WILL PROMOTE CONSIDERABLE BLOWING AND DRIFTING SNOW. FARTHER EAST...OBSERVATIONAL TRENDS AND SHORT-TERM RUC SOUNDINGS SUGGEST SLEET/FREEZING RAIN WILL LIKELY CHANGE OVER TO ALL SNOW ACROSS MUCH OF SOUTHWEST/WEST CENTRAL MO BY 02Z...INCLUDING THE JOPLIN/SPRINGFIELD/SEDALIA/CLINTON AREAS. ..GUYER.. 11/30/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LSX...SGF...EAX...TSA...TOP...ICT...OUN... 39069439 38879280 37739273 36789299 36519336 35949488 35499658 35069745 35379804 36379852 37119805 37829723 38429626  From mcd at goshenarc.org Thu Nov 30 23:25:32 2006 From: mcd at goshenarc.org (Mesoscale Convective Discussions) Date: Thu, 30 Nov 2006 18:25:32 -0500 Subject: [MCD] SWOMCD Message-ID: ACUS11 KWNS 302327 SWOMCD SPC MCD 302327 ILZ000-MOZ000-010400- MESOSCALE DISCUSSION 2251 NWS STORM PREDICTION CENTER NORMAN OK 0527 PM CST THU NOV 30 2006 AREAS AFFECTED...EAST CENTRAL MO/WEST CENTRAL IL CONCERNING...WINTER MIXED PRECIPITATION VALID 302327Z - 010400Z FREEZING RAIN AND MODERATE/HEAVY SLEET WILL REMAIN PREVALENT ACROSS EAST CENTRAL MO/WEST CENTRAL IL THROUGH MID/LATE EVENING...INCLUDING THE ST LOUIS METRO AREA AND PORTIONS OF I-70/I-44/I-55...WITH ADDITIONAL ICE ACCUMULATIONS VIA LIQUID EQUIVALENTS OF 0.10 IN/HR AND GREATER. WARM CONVEYOR/MOISTURE TRANSPORT REGIME AHEAD OF CYCLONE CURRENTLY CENTERED OVER EASTERN OK WILL CONTINUE TO MAINTAIN AN ELEVATED ABOVE-FREEZING LAYER INTO EAST CENTRAL MO/WEST CENTRAL IL THIS EVENING. THIS IS GENERALLY REPRESENTED BETWEEN 700-850 MB IN RUC POINT SOUNDINGS...SUFFICIENT FOR FULL/PARTIAL MELTING ABOVE A SHALLOW 1-KM SUB-FREEZING LAYER WITH SURFACE TEMPERATURES IN THE 20S. THIS OVERALL SCENARIO IS EXPECTED TO FLUCTUATE LITTLE THIS EVENING...UNTIL THE ARRIVAL OF THE CLOSED LOW/COLDER AIR LATER TONIGHT. WITH CONVECTIVELY ENHANCED ELEMENTS AND DEEP LAYER FORCING FOR ASCENT OVERSPREADING THE REGION...A MIX OF FREEZING RAIN/SLEET WILL REMAIN COMMON THROUGH MID/LATE EVENING IN EAST CENTRAL MO AREAS INCLUDING I-70/I-44 AND COLUMBIA/JEFFERSON CITY/ROLLA/ST LOUIS...AND WEST CENTRAL IL LOCALES INCLUDING QUINCY AND SPRINGFIELD/I-55. ..GUYER.. 11/30/2006 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...ILX...LSX...DVN...SGF... 39349200 39939147 40668982 40278908 39748913 38438978 37419065 37319100 37099169 37469228 38579232