From swody2 at goshenarc.org Wed Jan 3 17:22:05 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 03 Jan 2007 12:22:05 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 031726 SWODY2 SPC AC 031724 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1124 AM CST WED JAN 03 2007 VALID 041200Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS SE TX TO EXTREME SERN MS.... ...SYNOPSIS... PRONOUNCED MID/UPPER LEVEL CYCLONE IS EVIDENT IN MOISTURE CHANNEL IMAGERY OVER NWRN MEX. THIS SYSTEM IS EXPECTED TO EJECT ENEWD THEN EWD ACROSS WRN/CENTRAL TX...REACHING E TX OR VICINITY TX/LA BORDER AROUND 4/12Z BASED ON LATEST OPERATIONAL SPECTRAL/ETA FCST...AS WELL AS CONSENSUS OF 3/09Z ENSEMBLE RUNS. THIS WILL BE FOLLOWED BY HEIGHT FALLS ACROSS MUCH OF WRN CONUS...AS HIGH-AMPLITUDE/POSITIVELY-TILTED TROUGH EVOLVES FROM PERTURBATIONS NOW OVER N-CENTRAL PACIFIC. LOW LEVEL FRONTAL ZONE IS EVIDENT ATTM OVER CENTRAL/NRN GULF...WITH SFC BOUNDARY ROUGHLY LOCATED FROM VERACRUZ NWD TO ABOUT 100 NM SE BRO...THEN EWD TOWARD BUOY 42003...THEN ACROSS S-CENTRAL FL. AS MEX UPPER LOW APCHS...FRONTAL-WAVE LOW IS EXPECTED TO DEVELOP ALONG INFLECTION POINT OF SFC FRONTAL ZONE...OVER NWRN GULF. THIS LOW SHOULD MOVE NEWD ACROSS NWRN GULF AND ONSHORE BPT-LCH VICINITY EARLY IN PERIOD...HOWEVER POSITIONING/STRENGTH OF LOW WILL DEPEND STRONGLY ON MESOSCALE FACTORS INCLUDING PRECIP-RELATED MODULATION OF FRONTAL ZONE IN W GULF AREA. STRONGEST ASSOCIATED PRESSURE FALLS SHOULD MOVE NEWD INTO PROGRESSIVELY COLDER AND MORE STABLE AIR...LEAVING WAVY SFC FRONTAL ZONE LOCATED ACROSS SERN LA LATE IN PERIOD. ...W GULF COASTAL PLAIN TO MS DELTA... SCATTERED-NUMEROUS TSTMS ARE POSSIBLE THROUGHOUT PERIOD...SHIFTING GENERALLY EWD ACROSS REGION. ACTIVITY WILL OCCUR IN ENVIRONMENT OF STRONG VERTICAL SHEAR SUPPORTING SUPERCELLULAR MODE FOR DISCRETE STORMS AND BOWS/LEWPS WITHIN ANY LINES. INITIALLY ELEVATED AREA OF TSTMS LATE-DAY1 ACROSS S TX -- WITH MRGL HAIL THREAT -- MAY MOVE EWD FAST ENOUGH TO REACH WARM SECTOR AND BECOME SFC-BASED ACROSS SRN LA DURING THIS PERIOD. ADDITIONALLY...SEPARATE DEVELOPMENT IS POSSIBLE IN WEAKLY CAPPED MARINE AIR MASS THAT WILL BE CHARACTERIZED BY EFFECTIVE PARCELS ROOTED AT SFC AND DEW POINTS 60S F. EXPECT SFC THETAE TO OFFSET WEAK MIDLEVEL LAPSE RATES ENOUGH TO YIELD MLCAPES TO AROUND 1000 J/KG BY AFTERNOON. SLY/SELY SFC WINDS ALSO SHOULD BE COMMON ALONG AND S OF MARINE/WARM FRONT...CONTRIBUTING TO ENLARGED LOW LEVEL HODOGRAPHS. PRIMARY UNCERTAINTIES FOR SVR POTENTIAL INVOLVE COVERAGE OF INLAND PENETRATION OF MOST FAVORABLE WARM SECTOR AIR MASS...WITH GREATEST SVR PROBABILITIES NEAR COAST WHERE WARM/MARINE FRONT IS MOST LIKELY TO PENETRATE INLAND. ..EDWARDS.. 01/03/2007  From swody2 at goshenarc.org Thu Jan 4 05:59:48 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 04 Jan 2007 00:59:48 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 040604 SWODY2 SPC AC 040603 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1203 AM CST THU JAN 04 2007 VALID 051200Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM NRN FL TO SRN NC... ...SERN U.S... MODELS ARE IN MUCH BETTER AGREEMENT TONIGHT REGARDING THE EJECTING UPPER LOW ALONG THE GULF COAST OVER THE NEXT FEW DAYS. WITH TIME THIS FEATURE WILL DEAMPLIFY AS IT APPROACHES THE CAROLINAS...ALTHOUGH MID-HIGH LEVEL FLOW WILL CERTAINLY ENHANCE DEEP LAYER SHEAR/ORGANIZATIONAL POTENTIAL FOR CONVECTION THAT DEVELOPS AHEAD OF THE TROUGH. EARLIER CONCERNS OF LIMITED MOISTURE RETURN AHEAD OF RAPIDLY WEAKENING SFC FRONT HAVE SUBSIDED AS IT NOW APPEARS SFC DEW POINTS OF AT LEAST LOW-MID 60S SHOULD SPREAD INLAND WELL AHEAD OF WIND SHIFT/CONVECTIVE OUTFLOW...WITH HIGHER VALUES POSSIBLE NEAR THE GULF COAST. LATEST THINKING IS A CONSIDERABLE AMOUNT OF STRONGLY FORCED CONVECTION SHOULD BE ONGOING AT THE BEGINNING OF THE PERIOD OVER AL/FL PANHANDLE. THIS ACTIVITY SHOULD PROPAGATE EWD ACROSS THE REMAINDER OF NRN FL PENINSULA...AND SRN GA BY 00Z AS WELL DEFINED SHORTWAVE ENHANCES VERTICAL MOTION FIELD. ADDITIONALLY...IT APPEARS BOUNDARY LAYER HEATING MAY CONTRIBUTE SUBSTANTIALLY TO DESTABILIZATION AS LAPSE RATES STEEPEN AHEAD OF MAIN CONVECTIVE LINE. IT APPEARS SUFFICIENT RECOVERY WILL OCCUR ACROSS THE COASTAL CAROLINAS FOR STRONG/SEVERE CONVECTION AFTER 00Z. SHEAR PROFILES CERTAINLY SUPPORT THE POTENTIAL FOR SUPERCELLS...HOWEVER DOMINANT STORM MODE MAY ACTUALLY BE LINEAR GIVEN THE LIKELIHOOD OF PROGRESSIVE SQUALL LINE. IF SQUALL LINE IS THE DOMINANT MODE...DAMAGING WINDS SHOULD BE THE PRIMARY SEVERE THREAT. ..DARROW.. 01/04/2007  From swody2 at goshenarc.org Thu Jan 4 16:57:10 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 04 Jan 2007 11:57:10 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 041701 SWODY2 SPC AC 041700 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1100 AM CST THU JAN 04 2007 VALID 051200Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE SERN STATES... ...SERN STATES... THE CNTRL TX UPR LOW WILL EJECT ENEWD ACROSS THE WRN GULF COASTAL STATES TONIGHT THENCE DEAMPLIFY AND TRAVERSE THE SERN STATES AND SRN APPALACHIAN REGION DURING FRIDAY AND FRIDAY NIGHT. THE WEAKENING PHASE OF THIS WAVE WILL RESULT IN SFC FEATURES THAT BECOME LESS DEFINED DURING THE DAY WITH PERSISTENT RIDGING LIKELY OVER THE VAST MAJORITY OF THE SE COAST PER 12Z GFS. BELT OF ENHANCED LOW- AND MID-LEVEL FLOW BETWEEN THE ATLANTIC RIDGE AND THE UPSTREAM IMPULSE WILL ADVECT A HIGHER THETA-E AIR MASS NWD INTO NRN FL...SRN GA AND PARTS OF THE CAROLINAS TODAY AND FRIDAY. HEATING OF THIS AIR MASS WILL CONTRIBUTE TO DESTABILIZATION...WITH STRONGEST INSTABILITY LIKELY RELEGATED TO THE CNTRL/ERN FL PNHDL INTO NRN FL AND SRN GA DURING THE AFTN. A LINEAR MCS SHOULD BE ONGOING AT 12Z FRIDAY ACROSS CNTRL/SRN AL SWWD INTO THE NCNTRL GULF OF MEXICO. OVERALL STRUCTURE OF THE SQUALL LINE MAY TEND TO BECOME DISORGANIZED AND WEAKEN FRIDAY MORNING AS UPPER SUPPORT WEAKENS. CONVECTIVE OUTFLOWS...HOWEVER... MAY BE IMPETUS FOR ADDITIONAL STORMS /OR RE-INTENSIFICATION OF MORNING ACTIVITY/ DOWNSTREAM IN THE UNSTABLE ENVIRONMENT FRIDAY AFTN. THOUGH THE UPPER SYSTEM WILL WEAKEN WITH TIME...PRESENCE OF 50-70 KTS OF H5 FLOW WILL ENHANCE THE DEEP LAYER SHEAR SUFFICIENTLY FOR POSSIBLE SUPERCELLS. THIS WILL ESPECIALLY BE THE CASE WHERE BUOYANCY IS STRONGER IN THE FL PNHDL AND SRN GA. ACTIVITY SHOULD REMAIN ESSENTIALLY LINEAR...THOUGH...WITH A PRIMARY WIND DAMAGE THREAT AS ACTIVITY MOVES ENEWD ACROSS SRN GA AND NRN FL INTO PARTS OF THE CAROLINAS BY 00-03Z. ISOLD TORNADOES CANNOT BE RULED OUT WHERE MORE ROBUST TSTMS CAN DEVELOP. ..RACY.. 01/04/2007  From swody2 at goshenarc.org Fri Jan 5 06:15:10 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 05 Jan 2007 01:15:10 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 050619 SWODY2 SPC AC 050617 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1217 AM CST FRI JAN 05 2007 VALID 061200Z - 071200Z ...NO SVR TSTM AREAS FORECAST... A STRONG NORTHERN STREAM JET STREAK OVER THE NORTHERN PACIFIC IS NOSING TOWARD THE BRITISH COLUMBIA/PACIFIC NORTHWEST COAST... AND PROGGED TO CONTINUE EASTWARD...INLAND AND ACROSS THE CANADIAN/ NORTHERN AND CENTRAL U.S. ROCKIES LATER TODAY THROUGH SATURDAY/ SATURDAY NIGHT. AS THIS OCCURS...THE COMPLEX SPLIT UPPER FLOW PATTERN CURRENTLY IN PLACE ACROSS MUCH OF THE NATION IS FORECAST TO BEGIN CONSOLIDATING INTO A BROAD LARGE-SCALE TROUGH...WHICH WILL ENCOMPASS MOST AREAS EAST OF THE ROCKIES BY 12Z SUNDAY. THE EXCEPTION WILL BE THE SOUTHEAST...WHERE UPPER RIDGING WILL BUILD ONCE AGAIN SATURDAY IN THE WAKE OF REMNANTS OF A WEAKENING CLOSED LOW...NOW BEGINNING TO LIFT OUT OF THE SOUTH CENTRAL STATES. MODELS INDICATE THAT AN UPSTREAM IMPULSE WILL LIFT OUT OF THE SOUTHERN ROCKIES IN A POSITIVELY TILTED FASHION BY EARLY SATURDAY...TRAILING A MORE VIGOROUS NORTHERN BRANCH SHORT WAVE...WHICH IS PROGGED TO RAPIDLY LIFT FROM THE UPPER MISSISSIPPI VALLEY THROUGH THE ST. LAWRENCE VALLEY AND NORTHEAST BY EARLY SUNDAY. SOUTHERN SYSTEM APPEARS LIKELY TO BECOME INCREASINGLY SHEARED ACROSS THE LOWER MISSISSIPPI VALLEY AS IT APPROACHES THE UPPER RIDGE AXIS...WHILE ANOTHER MUCH STRONGER NORTHERN STREAM SHORT WAVE DIGS EAST OF THE ROCKIES INTO THE NORTH CENTRAL STATES. IN RESPONSE TO THE EVOLVING UPPER PATTERN...MODELS INDICATE A SURFACE LOW WILL DEEPEN AS IT LIFTS THROUGH THE ST. LAWRENCE VALLEY. THIS WILL FORCE THE PRIMARY SURFACE COLD FRONT EAST OF THE OHIO VALLEY AND OFF THE NORTH ATLANTIC COAST STATES BY EARLY SUNDAY. BUT...THIS BOUNDARY IS EXPECTED TO BE MUCH SLOWER TO PROGRESS EAST OF THE TENNESSEE VALLEY AND CENTRAL/EASTERN GULF STATES. ...NORTHERN ATLANTIC COAST... MODELS SUGGEST WEAK INSTABILITY WILL BE PRESENT IN AN AREA OF FOCUSED LOW-LEVEL WARM ADVECTION TO THE EAST OF THE DEEPENING SURFACE LOW...MAINLY NEAR SOUTHERN NEW ENGLAND COASTAL AREAS EARLY SATURDAY. THIS MAY BE SUFFICIENT TO CONTRIBUTE TO SCATTERED WEAK THUNDERSTORM ACTIVITY...BEFORE STRONGER FORCING SHIFTS WELL EAST OF COASTAL AREAS BY SATURDAY AFTERNOON. ...CNTRL/ERN GULF STATES AND TENNESSEE VALLEY... ANY SUPPRESSION OF MOISTURE LEVELS IN THE WAKE OF LEAD WEAKENING SOUTHERN BRANCH IMPULSE IS EXPECTED TO BE RELATIVELY MINOR/ SHORT-LIVED. HOWEVER...LAPSE RATES WILL BE WEAK...AND THIS IS LIKELY TO MINIMIZE CAPE ALONG/AHEAD...AND IN THE WAKE...OF SURFACE COLD FRONT AS IT SLOWLY ADVANCES EASTWARD ACROSS REGION. STRONGER FORCING FOR UPWARD VERTICAL MOTION WILL PROBABLY BE CONFINED TO A POST-FRONTAL BAND LATE IN THE PERIOD...FROM NORTHERN MISSISSIPPI THROUGH THE UPPER TENNESSEE VALLEY...WHERE BEST CHANCE FOR STORMS MAY EXIST. GIVEN THERMODYNAMIC ENVIRONMENT...HAIL POTENTIAL SEEMS REMOTE...AND EVEN IF A FEW STORMS DO DEVELOP IN THE PRE-FRONTAL REGIME...ISOLATED TORNADO/DAMAGING WIND POTENTIAL SEEMS NEGLIGIBLE DUE TO ANTICIPATED WEAK LOW-LEVEL FLOW/SMALL LOW-LEVEL HODOGRAPHS. ..KERR.. 01/05/2007  From swody2 at goshenarc.org Fri Jan 5 17:08:51 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 05 Jan 2007 12:08:51 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 051712 SWODY2 SPC AC 051710 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1110 AM CST FRI JAN 05 2007 VALID 061200Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...LWR MS VLY AND MID-SOUTH INTO THE SERN STATES... UPPER LOW MOVING ACROSS THE REGION TODAY WILL MOVE WELL OUT TO SEA BY SATURDAY. IN WAKE OF THIS SYSTEM...THE SURFACE COLD FRONT IS EXPECTED TO DECELERATE ACROSS NRN FL AND THE NRN GULF BASIN TONIGHT...THEN BEGIN LIFTING NWD SATURDAY AND SATURDAY NIGHT. UPSTREAM...A POSITIVE-TILT TROUGH WAS DIGGING SEWD THROUGH THE GREAT BASIN. SRN PORTION OF THIS TROUGH WILL LIKELY BEGIN TO SHEAR ACROSS THE MID-SOUTH ON SATURDAY...OWING TO THE MODEST UPPER RIDGE ACROSS THE SWRN ATLANTIC BASIN. THE COLD FRONT ACCOMPANYING THIS SYSTEM WILL BEGIN TO MOVE SEWD ACROSS THE TN AND LWR MS RVR VLYS SATURDAY NIGHT. RETURN FLOW WILL COMMENCE LATER TONIGHT ACROSS THE DEEP SOUTH AHEAD OF THE UPSTREAM WAVE/FRONT. LOW-LEVEL MOISTURE WILL ADVECT NWD...BUT A WARM/SUBSIDENT LAYER ALOFT BEHIND THE DEPARTING IMPULSE WILL LIKELY FAVOR SHALLOW CONVECTIVE CLOUDS AND LITTLE THUNDER THROUGH PEAK HEATING. CONVECTION IS LIKELY TO INCREASE/INTENSIFY... HOWEVER...SATURDAY NIGHT WITHIN THE INCREASING LOW- AND MID-LEVEL WARM/MOIST ADVECTION REGIME. TSTMS WILL BECOME MORE LIKELY AFTER 06Z...ESPECIALLY DOWNSTREAM FROM STRONGER HEIGHT FALLS AND ALONG/N OF THE COLD FRONT ACROSS ERN LA NWD INTO THE MID-SOUTH. ISOLD TSTMS MAY ALSO EVOLVE DOWNSTREAM AHEAD OF THE FRONT BY 12Z SUNDAY AS THE COLUMN GRADUALLY MOISTENS AND DESTABILIZES. SEVERE TSTM PROBABILITIES WILL LIKELY BE NEGLIGIBLE GIVEN POOR LAPSE RATES... MINIMAL INSTABILITY AND WEAK LOW-LEVEL FLOW. ...SERN NEW ENGLAND... A LOW PROBABILITY OF ISOLD TSTMS WILL EXIST BEFORE 18Z SATURDAY. SRN PERIPHERY OF WEAK H5 HEIGHT FALLS ASSOCD WITH A NRN STREAM WAVE WILL TRANSLATE ACROSS THE REGION EARLY IN THE DAY. FORECAST SOUNDINGS INDICATE THAT ELEVATED PARCELS WILL LIKELY BE LOFTED INTO THE ICING LAYER WITH MUCAPES OF 100-200 J/KG...INCREASING THE RISK FOR LIGHTNING. ..RACY.. 01/05/2007  From swody2 at goshenarc.org Sat Jan 6 05:40:11 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 06 Jan 2007 00:40:11 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 060544 SWODY2 SPC AC 060543 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1143 PM CST FRI JAN 05 2007 VALID 071200Z - 081200Z ...THERE IS A SLGT RISK OF SVR TSTMS LATE SUN AFTN/SUN NIGHT ACROSS PARTS OF THE SRN MID ATLANTIC COAST STATES.... IMPULSES EMBEDDED WITHIN COMPLEX SPLIT UPPER FLOW PATTERN STILL APPEAR LIKELY TO CONSOLIDATE INTO AN AMPLIFIED LARGE-SCALE TROUGH ENCOMPASSING MUCH OF THE CENTRAL/EASTERN STATES BY THE END OF THIS FORECAST PERIOD. THE PRIMARY IMPULSE EXPECTED TO SUPPORT THIS DEVELOPMENT IS READILY EVIDENT IN LATEST WATER VAPOR IMAGERY... DIGGING ACROSS THE NORTHWESTERN U.S...WITHIN THE NORTHERN BRANCH OF THE POLAR WESTERLIES. THE COLD...VIGOROUS SHORT WAVE TROUGH IS PROGGED TO CONTINUE TO DIG TO THE LEE OF THE ROCKIES...THROUGH THE NORTHERN AND CENTRAL PLAINS BY MIDDAY SUNDAY...BEFORE TURNING EASTWARD ACROSS THE UPPER HALF OF THE MISSISSIPPI VALLEY/THE OHIO VALLEY AND GREAT LAKES REGION BY 12Z MONDAY. AS THIS OCCURS... MODELS INDICATE THAT THE LARGER SCALE TROUGH WILL TAKE ON AN INCREASINGLY NEGATIVE TILT...ACCOMPANIED BY STRONG SURFACE CYCLOGENESIS FROM THE LEE OF THE APPALACHIANS THROUGH THE NORTH ATLANTIC COAST. ...SOUTHERN/MID ATLANTIC COAST STATES... MODELS SUGGEST THAT MODIFICATION OF BOUNDARY LAYER OVER THE NORTH CENTRAL GULF OF MEXICO...AND RETURN FLOW INTO THE SOUTHEASTERN STATES...WILL BE RAPID IN THE WAKE OF A WEAKENING LEAD SOUTHERN BRANCH SHORT WAVE TROUGH...NOW RAPIDLY LIFTING INTO/THROUGH THE SOUTH ATLANTIC COAST REGION. HOWEVER...COLDER AIR ALOFT...LAGGING WELL TO THE NORTH/WEST...IS NOT PROGGED TO OVERSPREAD RETURNING MOISTURE...AND LAPSE RATES WILL REMAIN WEAK IN EVOLVING WARM SECTOR THROUGH THIS FORECAST PERIOD. THIS WILL TEND TO MINIMIZE CAPE...AND MAY TEMPER SEVERE POTENTIAL ACROSS THE SOUTHEAST SUNDAY/SUNDAY NIGHT. STILL...A RISK OF SEVERE STORMS IS SUPPORTED BY ANTICIPATED FORCING FOR UPWARD VERTICAL MOTION ASSOCIATED WITH RAPID DEEPENING OF SURFACE LOW...WHICH MODELS INDICATE WILL COMMENCE TO THE LEE OF THE SOUTHERN APPALACHIANS SUNDAY EVENING. THIS WILL BE ACCOMPANIED BY STRENGTHENING LOW-LEVEL FLOW FIELDS...LIKELY INCLUDING A 50-70 KT SOUTHERLY LOW-LEVEL JET FROM THE CAROLINAS THROUGH THE DELMARVA PENINSULA BY LATE SUNDAY EVENING. INFLUX OF MOISTENING BOUNDARY LAYER OFF THE SOUTH ATLANTIC APPEARS LIKELY ACROSS AT LEAST THE COASTAL PLAIN OF EASTERN NORTHERN CAROLINA...WHERE LOW-LEVEL HODOGRAPHS TO THE EAST OF DEVELOPING CYCLONE WILL BE LARGE AND FAVORABLE FOR ISOLATED SUPERCELLS WITH TORNADOES. AS SURFACE LOW DEVELOPS INTO/OFF MID ATLANTIC COASTAL AREAS LATER SUNDAY NIGHT...A CONVECTIVE BAND...ACCOMPANYING EASTWARD SURGING COLD FRONT TO ITS SOUTH...COULD ENHANCE DOWNWARD MOMENTUM TRANSFER ACROSS THE SOUTHERN MID ATLANTIC COAST. ..KERR.. 01/06/2007  From swody2 at goshenarc.org Sat Jan 6 17:20:38 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 06 Jan 2007 12:20:38 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 061724 SWODY2 SPC AC 061722 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1122 AM CST SAT JAN 06 2007 VALID 071200Z - 081200Z ...THERE IS A SLGT RISK OF SVR TSTMS LATE SUN AFTN/SUN NIGHT OVER PARTS OF THE SRN MID ATLANTIC COAST STATES... ...DEEP SOUTH TO THE SRN MID-ATLANTIC REGION... 140+ KT H25 JET DIGGING SWD ALONG THE PAC NW COAST THIS MORNING WILL ENHANCE THE WAVE OVER THE NRN ROCKIES TODAY. THIS SHORTWAVE TROUGH WILL THEN DIG SEWD INTO THE CNTRL/NRN PLAINS AND BECOME MORE NEGATIVELY TILTED BEFORE MOVING INTO THE UPPER MIDWEST BY 12Z MONDAY. AHEAD OF THIS SYSTEM...THE FRONT SITUATED ALONG THE NRN GULF BASIN TODAY WILL RAPIDLY DEVELOP NWD ACROSS THE SERN STATES AND INTO THE MID-ATLANTIC REGION SUNDAY AND SUNDAY NIGHT. CYCLOGENESIS WILL TAKE PLACE LATE TONIGHT VCNTY SRN LA COAST. THIS LOW WILL THEN TRANSLATE NEWD TO THE WEST OF THE APPALACHIAN MOUNTAIN CHAIN ON SUNDAY WITH PERHAPS A WEAK LOW FORMING OVER DELMARVA BY EARLY MONDAY. TRAILING THE LOW...A COLD FRONT WILL SWEEP EWD FROM THE LWR MS VLY TO A POSITION FROM CNTRL VA SWWD TO SERN GA AND NRN FL BY MONDAY MORNING. 12Z RAOBS EXHIBITED POOR LAPSE RATES ACROSS THE DEEP S AND SERN STATES OWING TO WARM TROPOSPHERIC TEMPERATURES ASSOCIATED WITH THE DEEP LAYER RIDGE OVER THE AREA. BOUNDARY LAYER MOISTURE WILL RAPIDLY RETURN NWD AHEAD OF THE NEXT IMPULSE WITH LWR-MID 60S SFC DEW POINTS LIKELY COMMON ACROSS THE SERN STATES AND SRN MID-ATLANTIC REGION BY SUNDAY NIGHT. THERMAL BUOYANCY WILL LIKELY BE MITIGATED BY THE CONTINUED POOR LAPSE RATES ALOFT...HOWEVER. 12Z NAM/GFS AGREE THAT AN INCREASING LLJ WILL ENHANCE THETA-E ADVECTION IN THE LEE OF THE APPALACHIANS SUNDAY EVE. THIS SHOULD SUPPORT INCREASING CONVECTION/TSTMS THAT WILL MOVE NWD FROM SERN GA TO THE SRN MID-ATLANTIC SUNDAY AFTN/NIGHT. THOUGH INSTABILITY WILL BE MINIMAL...LOW-LEVEL HODOGRAPHS EXHIBIT STRONG VEERING WITH HEIGHT AMIDST A MOISTENING BOUNDARY LAYER. AS A RESULT...BRIEF TORNADOES CANNOT BE RULED OUT WITH MORE SUSTAINED STORMS... ESPECIALLY OVER THE COASTAL PLAINS OF SC...NC AND SERN VA. OTHERWISE...A LOOSELY ORGANIZED LINEAR MCS SHOULD GRADUALLY EVOLVE ALONG THE COLD FRONT SUNDAY AFTN AND NIGHT AS STRONGER LARGE SCALE HEIGHT FALLS ASSOCD WITH THE APPROACHING TROUGH SPREAD EWD. STEEPEST MID-TROPOSPHERIC LAPSE RATES WILL PASS THROUGH THE OH VLY. THUS...INSTABILITY WILL PROBABLY REMAIN RATHER MEAGER ALONG THE FRONT. BUT...ENHANCED FLOW ALOFT AND INCREASING CROSS-COMPONENT FLOW WITH RESPECT TO THE COLD FRONT ALONG THE BASE OF THE UPPER TROUGH SUGGEST THAT ISOLD TSTMS MAY BOW...INCREASING THE RISK OF A DAMAGING WIND GUST OR BRIEF TORNADO ACROSS THE DEEP SOUTH AND PARTS OF THE SERN STATES SUNDAY AFTN/NIGHT. ..RACY.. 01/06/2007  From swody2 at goshenarc.org Sun Jan 7 05:45:32 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 07 Jan 2007 00:45:32 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 070549 SWODY2 SPC AC 070548 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1148 PM CST SAT JAN 06 2007 VALID 081200Z - 091200Z ...NO SVR TSTM AREAS FORECAST... MODELS INDICATE THAT THE AMPLIFIED POLAR TROUGH...DEVELOPING OVER THE CENTRAL/EASTERN U.S. TODAY...WILL PERSIST THROUGH THIS FORECAST PERIOD. THE MOST VIGOROUS EMBEDDED IMPULSE IS PROGGED TO LIFT RAPIDLY OUT OF THE LOWER GREAT LAKES/OHIO VALLEY INTO THE CANADIAN MARITIMES BY 12Z TUESDAY. BUT...THIS IS PROGGED TO OCCUR AS ANOTHER SIGNIFICANT SHORT WAVE TROUGH DIGS THROUGH THE MISSOURI VALLEY. FARTHER UPSTREAM...ANOTHER LARGE COLD UPPER TROUGH LIKELY WILL DIG ACROSS THE NORTHEAST PACIFIC...TOWARD THE BRITISH COLUMBIA /NORTHERN U.S. PACIFIC COAST. STABILIZATION ASSOCIATED WITH A COLD FRONT AND REINFORCING COLD SURGE ACCOMPANYING THE EASTERN TROUGH IS EXPECTED TO PRECLUDE CONVECTIVE POTENTIAL ACROSS MUCH OF THE NATION MONDAY/MONDAY NIGHT. HOWEVER...THE LOW/MID-LEVEL FRONTAL ZONE MAY STILL BE INLAND OF ATLANTIC COASTAL AREAS EARLY IN THE PERIOD. THIS WILL MAINTAIN AT LEAST A LOW PROBABILITY OF THUNDERSTORMS FROM PARTS OF THE SOUTHERN MID ATLANTIC COAST INTO NEW ENGLAND THROUGH MONDAY MORNING...BUT THE RISK LIKELY WILL END BY MID DAY AS THE FRONT FINALLY ADVANCES OFFSHORE. THE BOUNDARY MAY NOT CLEAR THE SOUTHERN FLORIDA PENINSULA UNTIL EARLY MONDAY EVENING...BUT MID-LEVEL INHIBITION IN FORECAST SOUNDINGS APPEARS TOO STRONG FOR AN APPRECIABLE RISK OF THUNDERSTORMS...GIVEN WEAK UPPER FORCING ACROSS THIS REGION. ...MID ATLANTIC COAST... BETTER LOW-LEVEL MOISTURE ALONG PROGGED INTENSE PRE-FRONTAL SOUTHERLY LOW-LEVEL JET AXIS MAY ALREADY BE OFFSHORE BY 12Z MONDAY. AND...PRE-FRONTAL SURFACE FLOW MAY BE IN THE PROCESS OF VEERING. HOWEVER...THE FRONT MAY STILL CONTRIBUTE TO SUFFICIENT FORCING FOR AT LEAST A WEAK CONVECTIVE BAND...WHICH MAY ENHANCE DAMAGING WIND POTENTIAL VIA DOWNWARD TRANSFER OF MOMENTUM ASSOCIATED WITH 50+ KT MEAN ENVIRONMENTAL FLOW. THREAT WILL DIMINISH AS SURFACE BOUNDARY CLEARS COASTAL AREAS...LIKELY BY THE 15-18Z TIME FRAME MONDAY. ..KERR.. 01/07/2007  From swody2 at goshenarc.org Sun Jan 7 16:44:41 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 07 Jan 2007 11:44:41 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 071648 SWODY2 SPC AC 071647 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1047 AM CST SUN JAN 07 2007 VALID 081200Z - 091200Z ...NO SVR TSTM AREAS FORECAST... ...SRN MID-ATLANTIC REGION... PLAINS MID-LEVEL TROUGH WILL MOVE QUICKLY EWD AND OFF THE ERN SEABOARD BY MONDAY NIGHT AS THE NEXT SPEED MAX TRANSLATES SEWD ACROSS THE NRN TIER OF THE COUNTRY. FRONT ASSOCD WITH THE LEAD DISTURBANCE SHOULD BE SITUATED FROM NY SWD ACROSS THE ERN SLOPES OF THE APPALACHIAN MOUNTAINS TO THE ERN GULF BASIN AT 12Z MON. BANDS OF CONVECTION/TSTMS WILL LIKELY BE PRESENT ALONG/E OF THE FRONT ACROSS THE SRN MID-ATLANTIC REGION MON MORNING. THIS ACTIVITY WILL MOVE OFF THE COAST BETWEEN 18-21Z. THE STRONGER FORCING FOR ASCENT AND STEEP LAPSE RATES ASSOCD WITH THE UPPER TROUGH WILL MOVE PRIMARILY N OF THE MORE SUBSTANTIAL WARM SECTOR CONFINED TO THE SERN STATES. THUS...PROSPECTS FOR A WELL-ORGANIZED SEVERE MCS ARE UNLIKELY. BUT...ISOLD DAMAGING WIND GUSTS CANNOT BE RULED OUT ALONG NRN PORTIONS OF THE THETA-E AXIS ACROSS ESPECIALLY ERN NC NWD INTO SERN VA AND THE LWR-ERN MD SHORE THROUGH EARLY AFTN. FORECAST SOUNDINGS SUGGEST THAT VERY STRONG WINDS JUST ABOVE THE SFC MAY BE MIXED DOWNWARD IN THE STRONGER SFC-BASED CONVECTIVE CELLS ALONG THE FRONT. CONVECTION WILL LIKELY WEAKEN WITH SWD EXTENT ALONG THE COLD FRONT INTO THE SERN STATES AS PRIMARY FORCING LIFTS NEWD AWAY FROM THE REGION. ..RACY.. 01/07/2007  From swody2 at goshenarc.org Mon Jan 8 05:39:18 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 08 Jan 2007 00:39:18 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 080542 SWODY2 SPC AC 080541 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1141 PM CST SUN JAN 07 2007 VALID 091200Z - 101200Z ...NO SVR TSTM AREAS FORECAST... MODELS INDICATE THAT A LARGE-SCALE POLAR TROUGH WILL REMAIN AMPLIFIED ACROSS THE EASTERN STATES THROUGH LATE TUESDAY...AS A SIGNIFICANT SHORT WAVE IMPULSE CONTINUES INTO/THROUGH ITS BASE... ACROSS THE SOUTHERN MID ATLANTIC COAST STATES. THEREAFTER...THE SHORT WAVE IS PROGGED TO LIFT INTO THE WESTERN ATLANTIC...WITH A BIT MORE ZONAL FLOW DEVELOPING EAST OF THE MISSISSIPPI VALLEY...WELL AHEAD OF THE NEXT POLAR TROUGH DIGGING INTO THE NORTHWESTERN STATES. A WEAK TROUGH IN THE SUBTROPICAL STREAM IS PROGGED TO LIFT TOWARD BAJA IN ADVANCE OF THE LATTER FEATURE. AND...MID/HIGH LEVEL MOISTURE WILL BEGIN TO ADVECT ACROSS THE NORTHERN MEXICAN PLATEAU TOWARD THE SOUTH CENTRAL STATES. HOWEVER...THE CENTER OF A SURFACE RIDGE...SHIFTING SOUTHEASTWARD INTO THE WESTERN GULF STATES DURING THE DAY TUESDAY...WILL NOT BEGIN TO RETREAT UNTIL VERY LATE IN THE FORECAST PERIOD. UNTIL THIS OCCURS...MODIFICATION OF THE BOUNDARY LAYER OVER THE WESTERN GULF OF MEXICO...AND A RETURN FLOW INLAND...WILL BE INHIBITED. A DRY STABLE ENVIRONMENT WILL RESULT IN A NEGLIGIBLE RISK OF THUNDERSTORMS DURING THIS PERIOD ACROSS MUCH OF THE NATION...WITH PARTS OF THE PACIFIC NORTHWEST A POSSIBLE EXCEPTION. ...PACIFIC NORTHWEST... MODELS SUGGEST THAT THE COLD CORE OF THE UPPER TROUGH /WITH 700-500 MB TEMPERATURES OF -20 TO -40 C/ WILL MIGRATE INLAND ACROSS THE PACIFIC NORTHWEST COAST TUESDAY NIGHT. AND...LOW-LEVEL MOISTENING ASSOCIATED WITH ONSHORE FLOW TO THE WEST OF THE CASCADES MAY CONTRIBUTE TO SUFFICIENT CAPE THROUGH THE LOWERING MIXED PHASE LAYER...WITH FAVORABLY COLD EQUILIBRIUM LEVELS...TO SUPPORT A RISK FOR SCATTERED THUNDERSTORM ACTIVITY. ..KERR.. 01/08/2007  From swody2 at goshenarc.org Mon Jan 8 16:56:34 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 08 Jan 2007 11:56:34 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 081659 SWODY2 SPC AC 081657 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1057 AM CST MON JAN 08 2007 VALID 091200Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...PACIFIC NW... STRONG POST FRONTAL COLD ADVECTION WILL DRAMATICALLY STEEPEN LAPSE RATE ENVIRONMENT ACROSS THE PACIFIC NW DURING THE LATTER HALF OF THE PERIOD. FORECAST SOUNDINGS FOR COASTAL WA/NW ORE SUGGEST BOUNDARY LAYER CONVECTION WILL DEVELOP WITHIN ONSHORE FLOW REGIME AROUND 00Z...WITH ACTIVITY EXPECTED TO DEEPEN SUFFICIENTLY FOR LIGHTNING WITHIN LOW-TOPPED UPDRAFTS...ALTHOUGH EL LEVELS WILL GRADUALLY RISE TO NEAR 500MB BY THE END OF THE PERIOD. COLD PROFILES SUGGEST SMALL HAIL MAY ACCOMPANY THE STRONGER UPDRAFTS. ...LAKE ONTARIO... LAPSE RATES WILL STEEPEN...ESPECIALLY AFTER 00Z...ACROSS LAKE ONTARIO WITHIN NW FLOW BENEATH UPPER TROUGH TUESDAY. ALTHOUGH LAKE EFFECT SHOWERS SHOULD EVOLVE...OVER/DOWNWIND OF THE LAKE...AS THERMODYNAMIC PROFILES BECOME MORE UNSTABLE...IT APPEARS LIGHTNING WILL BE EXTREMELY ISOLATED AND WILL NOT OUTLOOK THUNDERSTORMS ACROSS THIS REGION. ..DARROW.. 01/08/2007  From swody2 at goshenarc.org Tue Jan 9 05:02:54 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 09 Jan 2007 00:02:54 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 090506 SWODY2 SPC AC 090505 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1105 PM CST MON JAN 08 2007 VALID 101200Z - 111200Z ...NO SVR TSTM AREAS FORECAST... MODELS INDICATE THAT THE POLAR TROUGH PROGGED TO DIG INTO THE NORTHWESTERN U.S. BY 12Z WEDNESDAY WILL BE ACCOMPANIED BY A SIGNIFICANT COLD INTRUSION. THIS WILL OCCUR TO THE LEE OF THE NORTHERN ROCKIES...AS ONE VIGOROUS EMBEDDED IMPULSE PROGRESSES EASTWARD THROUGH THE CENTRAL CANADIAN/U.S. BORDER AREA BY 12Z THURSDAY. THE COLD FRONT WILL ALSO SURGE THROUGH MUCH OF THE NORTHERN AND CENTRAL GREAT BASIN...AS ANOTHER SIGNIFICANT IMPULSE DIGS SOUTHWARD ACROSS THE PACIFIC COAST STATES. IN ADVANCE OF THE LATTER FEATURE...AN INCREASING SHEARED TROUGH IN THE SUBTROPICAL STREAM IS PROGGED TO BEGIN LIFTING ACROSS BAJA AND THE NORTHERN MEXICAN PLATEAU...INTO PARTS OF THE SOUTHERN ROCKIES AND SOUTH CENTRAL STATES. THIS LIKELY WILL BE ACCOMPANIED BY AN INFLUX OF MOISTURE IN AN UPPER PLUME OFF THE LOWER LATITUDE PACIFIC...WHICH WILL BEGIN TO GRADUALLY SATURATE THE ENVIRONMENT IN PROGRESSIVELY LOWER LEVELS. WHILE A SOUTHERLY LOW-LEVEL FLOW WILL PROBABLY DEVELOP OFF THE WESTERN GULF OF MEXICO INTO THE SOUTHERN PLAINS TOWARD THE END OF THE PERIOD...THE GULF BOUNDARY LAYER IS EXPECTED TO BE JUST BEGINNING TO MODIFY...IN THE WAKE OF A RETREATING SURFACE RIDGE. ...EAST OF THE ROCKIES... NEAR MOIST ADIABATIC LAPSE RATES WITHIN ELEVATED PACIFIC MOIST PLUME AND LIMITED LOW-LEVEL MOISTURE RETURN FROM THE GULF OF MEXICO ARE EXPECTED TO INHIBIT DESTABILIZATION...RESULTING IN NEGLIGIBLE RISK FOR THUNDERSTORMS WEDNESDAY/WEDNESDAY NIGHT. ...WEST OF ROCKIES... SURFACE COLD FRONT SURGING AHEAD OF MID-LEVEL COLD CORE WILL INHIBIT DESTABILIZATION ACROSS MUCH OF THE INTERMOUNTAIN WEST. HOWEVER...POST-FRONTAL LOW-LEVEL TEMPERATURES WEST OF THE CASCADES ...BENEATH UPPER COLD CORE...MAY REMAIN WARM ENOUGH TO SUPPORT VERY WEAK CAPE. THIS MAY EXTEND THROUGH A RATHER SHALLOW LAYER...BUT MIXED PHASE LAYER WILL BE LOW...AND EQUILIBRIUM LEVEL TEMPERATURES SHOULD BE FAVORABLY COLD FOR ISOLATED/WIDELY SCATTERED THUNDERSTORM ACTIVITY. ..KERR.. 01/09/2007  From swody2 at goshenarc.org Fri Jan 12 06:24:21 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 12 Jan 2007 01:24:21 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 120614 SWODY2 SPC AC 120613 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1213 AM CST FRI JAN 12 2007 VALID 131200Z - 141200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... POSITIVELY TILTED UPPER TROUGH WILL CONTINUE TO DROP SLOWLY SWD AND INTO THE SWRN U.S. SATURDAY. DOWNSTREAM FROM THIS FEATURE...A BROAD LOW AMPLITUDE UPPER RIDGE WILL EXIST FROM THE MS VALLEY EWD THROUGH PARTS OF THE OH VALLEY AND SERN STATES. AT THE SURFACE A COLD ARCTIC FRONT WILL CONTINUE SWD. BY 12Z SATURDAY THIS BOUNDARY SHOULD EXTEND FROM THE NERN U.S. SWWD INTO THE LOWER MS VALLEY THROUGH CNTRL AND WRN TX. THIS SHALLOW WEDGE OF COLD AIR SHOULD CONTINUE SLOWLY SWD THROUGH TX DURING THE DAY. ...SWRN THROUGH S CNTRL AND ERN TX... PARTIALLY MODIFIED GULF AIR WITH BOUNDARY LAYER DEWPOINTS MAINLY IN THE LOW TO MID 60S WILL HAVE ADVECTED NWD INTO THE PRE-FRONTAL WARM SECTOR OF SRN AND S CNTRL TX INTO THE LOWER MS VALLEY. SOMEWHAT STRONGER MID LEVEL LAPSE RATES AROUND 6.5 C/KM INITIALLY OVER SWRN TX MAY ADVECT INTO PARTS OF S CNTRL TX ABOVE THE RETURNING LOW LEVEL MOISTURE. THIS ALONG WITH POTENTIAL FOR PRE-FRONTAL SURFACE HEATING SHOULD CONTRIBUTE TO SOME DESTABILIZATION DURING THE DAY WITH MUCAPE FROM 400 TO 800 J/KG NEAR AND JUST S OF THE FRONT. MODELS SUGGEST CONVECTION MAY ALREADY BE IN PROGRESS FROM PARTS OF NERN TX...ERN OK INTO THE LOWER MS VALLEY. HOWEVER...THIS ACTIVITY WILL BE ELEVATED IN POST FRONTAL ZONE WHERE CAPE WILL BE LIMITED. OTHER STORMS MAY DEVELOP DURING THE AFTERNOON IN VICINITY OF THE FRONT AS THE ATMOSPHERE DESTABILIZES. HOWEVER...ORIENTATION OF THE MEAN DEEP LAYER FLOW WITH RESECT THE FRONT SUGGEST STORMS WILL LIFT NEWD OVER THE COOL FRONTAL SURFACE AND BECOME ELEVATED...ESPECIALLY OVER S CNTRL THROUGH SWRN TX. STORMS MAY INCREASE OVERNIGHT NEAR AND N OF THE FRONT AS THE SLY LOW LEVEL JET AND FORCING FOR ASCENT STRENGTHENS DOWNSTREAM FROM ADVANCING UPPER TROUGH. VERTICAL SHEAR FOR STORMS DEVELOPING NEAR THE FRONT WILL BE SUFFICIENT FOR SUPERCELLS. HOWEVER...TENDENCY WILL REMAIN FOR STORMS TO LIFT NEWD AND BECOME ELEVATED. INSTABILITY AND MID LEVEL LAPSE RATES MAY BECOME SUFFICIENT FOR A THREAT OF MARGINALLY SEVERE HAIL. FARTHER EAST ACROSS PARTS OF ERN TX...A MORE NE ORIENTATION OF THE FRONT SUGGESTS ANY STORMS DEVELOPING ALONG OR S OF THIS PART OF THE BOUNDARY MAY HAVE A BETTER CHANCE OF REMAINING SURFACE BASED. HOWEVER...MODEST LAPSE RATES/INSTABILITY AND WEAKER FORCING FOR DEEP LAYER ASCENT IN THIS REGION SHOULD SERVE AS LIMITING FACTORS. ..DIAL.. 01/12/2007  From swody2 at goshenarc.org Fri Jan 12 17:17:32 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 12 Jan 2007 12:17:32 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 121720 SWODY2 SPC AC 121719 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1119 AM CST FRI JAN 12 2007 VALID 131200Z - 141200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... WRN U.S. MID-LEVEL TROUGH IS FORECAST TO BEGIN MAKING MORE SUBSTANTIAL EWD PROGRESS...PARTICULARLY THROUGH THE LATTER HALF OF THE PERIOD. MEANWHILE...SURFACE COLD FRONT WILL CONTINUE MOVING SWD ACROSS TX...WHILE REMAINING QUASI-STATIONARY FROM AR ENEWD ACROSS THE OH VALLEY REGION. THOUGH LACK OF INSTABILITY WILL PRECLUDE THUNDERSTORMS ACROSS MUCH OF THE COUNTRY...LOW-LEVEL WARM/MOIST ADVECTION AHEAD OF APPROACHING UPPER TROUGH WILL CONTRIBUTE TO WIDESPREAD SHOWERS AND THUNDERSTORMS OVER THE S CENTRAL CONUS. ...MIDDLE RIO GRANDE VALLEY ENEWD INTO ERN TX... SHOWERS AND THUNDERSTORMS SHOULD BE ONGOING AT THE START OF THE PERIOD ACROSS THE SRN PLAINS/AR...NEAR AND N OF SWD-MOVING COLD FRONT. WHILE WIDESPREAD PRECIPITATION SHOULD LIMIT POTENTIAL FOR DESTABILIZATION...MODELS DO SUGGEST SLIGHTLY STEEPER LAPSE RATES SHOULD ADVECT NEWD WHICH MAY CONTRIBUTE TO AOB 500 J/KG MOST-UNSTABLE CAPE BY THE AFTERNOON. DEEP-LAYER WIND FIELD -- FEATURING 50 KT SWLY FLOW AT MID-LEVELS -- WILL YIELD SHEAR SUFFICIENT FOR SUPERCELLS. HOWEVER...WEAKLY-CAPPED AIRMASS S OF FRONT -- ALONG WITH TENDENCY FOR ANY SURFACE-BASED STORMS WHICH CAN DEVELOP TO MOVE NNEWD ACROSS THE FRONT -- SHOULD LIMIT MAIN SEVERE THREAT TO HAIL WITH ELEVATED STORMS N OF BOUNDARY. ALONG WITH THE POTENTIAL FOR AN ISOLATED WIND GUST OR BRIEF TORNADO WITH A SURFACE-BASED STORM OR TWO NEAR OR JUST N OF THE FRONT...POTENTIAL FOR A FEW MARGINALLY-SEVERE HAILSTONES SUPPORTS THE CONTINUANCE OF 5% PROBABILITY SEVERE AREA THIS PERIOD. ..GOSS.. 01/12/2007  From swody2 at goshenarc.org Sat Jan 13 11:04:34 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 13 Jan 2007 06:04:34 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 131107 SWODY2 SPC AC 131106 DAY 2 CONVECTIVE OUTLOOK RESENT 1 NWS STORM PREDICTION CENTER NORMAN OK 0506 AM CST SAT JAN 13 2007 VALID 141200Z - 151200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... POSITIVELY TILTED UPPER TROUGH NOW FROM THE NRN ROCKIES TO THE GREAT BASIN REGION WILL CONTINUE SLOWLY EWD THROUGH SUNDAY. A SHORTWAVE TROUGH WILL ROTATE THROUGH BASE OF THE UPPER TROUGH AND EJECT NEWD THROUGH THE CNTRL PLAINS AND MID-UPPER MS VALLEY THIS PERIOD. AS THIS OCCURS A WEAK WAVE WILL DEVELOP ALONG THE FRONT OVER THE LOWER MS VALLEY SUNDAY AFTERNOON AND LIFT NEWD INTO THE OH VALLEY SUNDAY NIGHT. THIS WILL PROVIDE IMPETUS FOR THE ARCTIC FRONT TO CONTINUE SEWD THROUGH MUCH OF THE REMAINDER OF S TX THROUGH THE LOWER MS VALLEY SUNDAY NIGHT. ...S TX THROUGH THE LOWER MS VALLEY... MOIST BOUNDARY LAYER AIR WITH DEWPOINTS IN THE MID 60S WILL PERSIST IN THE PRE-FRONTAL WARM SECTOR ACROSS MUCH OF S AND ERN TX INTO THE LOWER MS VALLEY SUNDAY. HOWEVER...WEAK MID LEVEL LAPSE RATES AND LIMITED SURFACE HEATING SUGGEST INSTABILITY WILL REMAIN VERY MARGINAL WITH MUCAPE BELOW 500 J/KG. LOW LEVEL JET INITIALLY OVER SRN AND ERN TX EARLY SUNDAY WILL SHIFT NEWD INTO THE LOWER MS VALLEY LATER IN THE DAY AND INTO THE TN VALLEY OVERNIGHT ALONG TRACK OF DEVELOPING SURFACE LOW. HOWEVER...STRONGER FORCING ASSOCIATED WITH EJECTING SHORTWAVE TROUGH WILL REMAIN ON COLD...STABLE SIDE OF FRONT...SUGGESTING CYCLOGENESIS WILL BE WEAK. POST FRONTAL ELEVATED CONVECTION WILL BE ONGOING EARLY SUNDAY FROM S CNTRL TX NEWD INTO THE LOWER MS VALLEY. ACTIVITY WILL SHIFT SLOWLY EWD DURING THE DAY. MOST STORMS SHOULD REMAIN CONFINED TO NEAR OR BEHIND ARCTIC FRONT DUE TO UNFAVORABLE THERMODYNAMIC PROFILES AND WEAK FORCING FOR ASCENT IN WARM SECTOR. DESPITE FAVORABLE HODOGRAPHS FOR SUPERCELLS AND ISOLATED TORNADOES WITHIN PRE-FRONTAL WARM SECTOR ALONG TRACK OF LOW LEVEL JET...SEVERE THREAT THIS PERIOD IS EXPECTED TO REMAIN LIMITED DUE TO AN ANTICIPATED VERY MARGINAL THERMODYNAMIC ENVIRONMENT. IF IT BEGINS TO APPEAR MORE SURFACE BASED INSTABILITY WILL DEVELOP THAN CURRENTLY EXPECTED...AN UPGRADE TO SLIGHT RISK MAY BE NEEDED IN LATER OUTLOOKS. ..DIAL.. 01/13/2007  From swody2 at goshenarc.org Sun Jan 14 05:43:54 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 14 Jan 2007 00:43:54 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 140547 SWODY2 SPC AC 140546 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1146 PM CST SAT JAN 13 2007 VALID 151200Z - 161200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... POSITIVELY TILTED UPPER TROUGH WILL EXTEND FROM THE UPPER MS VALLEY SWWD THROUGH THE SWRN STATES MONDAY. A STRONG SHORTWAVE TROUGH NOW ROTATING THROUGH BASE OF UPPER TROUGH OVER AZ WILL CONTINUE NEWD THROUGH THE GREAT LAKES AND INTO THE NERN U.S. THIS PERIOD. ATTENDANT SURFACE LOW INITIALLY OVER THE OH VALLEY WILL MOVE NE AND OFFSHORE MONDAY NIGHT. TRAILING ARCTIC FRONT WILL CONTINUE TO SURGE SWD THROUGH THE REMAINDER OF THE SRN PLAINS...LOWER MS VALLEY AND MUCH OF THE SERN STATES. ...S THROUGH S CNTRL TX... ISENTROPIC LIFT IN WAKE OF SWD ADVANCING ARCTIC FRONT AND SHORTWAVE TROUGHS EMBEDDED WITHIN SUBTROPICAL MOIST PLUME WILL CONTRIBUTE TO THE DEVELOPMENT OF PRECIPITATION IN POST FRONTAL ZONE OVER PARTS OF TX INTO THE LOWER MS VALLEY. FORECAST SOUNDING SHOW SOME CONVECTIVE INSTABILITY IN THE 700 MB TO 500 MB MIXED PHASE LAYERS OVER PARTS OF S THROUGH S CNTRL TX. HOWEVER...MID LEVEL LAPSE RATES WILL BE WEAK RESULTING IN LIMITED INSTABILITY WITH MUCAPE AOB 200 J/KG. LIGHTNING STRIKES COULD ACCOMPANY SOME OF THIS ELEVATED...SHALLOW CONVECTION. HOWEVER...WEAK INSTABILITY AND POOR LAPSE RATES SUGGEST ANY LIGHTING ACTIVITY SHOULD REMAIN ISOLATED. ..DIAL.. 01/14/2007  From swody2 at goshenarc.org Sun Jan 14 17:00:04 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 14 Jan 2007 12:00:04 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 141703 SWODY2 SPC AC 141701 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1101 AM CST SUN JAN 14 2007 VALID 151200Z - 161200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... LARGE UPPER TROUGH OVER THE WRN AND CENTRAL CONUS WILL TAKE ON AN INCREASINGLY-POSITIVE TILT...AS NRN PORTION OF THE TROUGH SHIFTS EWD ACROSS THE NRN HALF OF THE CONUS WHILE SRN PORTION LINGERS OVER THE SWRN CONUS. AT THE SURFACE...LOW INITIALLY OVER THE MID/UPPER OH VALLEY REGION -- ASSOCIATED WITH NRN PORTION OF THE UPPER TROUGH -- WILL MOVE NEWD ACROSS NEW ENGLAND AND LIKELY INTO THE ATLANTIC BY THE END OF THE PERIOD. TRAILING COLD FRONT WILL SURGE SWD OUT OF THE S CENTRAL U.S. INTO MEXICO/THE GULF OF MEXICO EARLY...WHILE ALSO MOVING SEWD ACROSS THE MID-ATLANTIC REGION/THE SOUTHEAST THROUGH 16/12Z. ...PORTIONS OF CENTRAL/ERN/S TX... COLD FRONT SHOULD EXTEND FROM SRN LA SWWD ACROSS THE WRN GULF INTO DEEP S TX AT THE START OF THE PERIOD...AND SHOULD CROSS THE RIO GRANDE INTO NERN MEXICO SHORTLY AFTER THE START OF THE PERIOD. ABOVE PRONOUNCED NLY SURFACE WINDS...LOW-LEVEL FLOW WILL REMAIN FROM A SLY DIRECTION -- AT LEAST DURING THE FIRST HALF OF THE PERIOD. THE RESULTING ISENTROPIC LIFT/WARM ADVECTION OVER THE SHALLOW SURFACE COLD LAYER WILL RESULT IN PRECIPITATION...AND POSSIBLY A FEW EMBEDDED/ELEVATED THUNDERSTORMS. MINIMAL INSTABILITY WILL PRECLUDE ANY SEVERE THREAT...AND THUNDERSTORM POTENTIAL SHOULD DECREASE WITH TIME. ...ELSEWHERE... POTENTIAL FOR A LIGHTNING STRIKE OR TWO MAY SHIFT EWD FROM THE MID OH VALLEY REGION ACROSS THE CENTRAL APPALACHIANS AND MID-ATLANTIC REGION THROUGH THE FIRST HALF OF THE PERIOD AHEAD OF COLD FRONT. HOWEVER...INSTABILITY APPEARS INSUFFICIENT TO WARRANT THE INCLUSION OF A 10% PROBABILITY THUNDER LINE ATTM. ..GOSS.. 01/14/2007  From swody2 at goshenarc.org Mon Jan 15 05:32:27 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 15 Jan 2007 00:32:27 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 150535 SWODY2 SPC AC 150534 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1134 PM CST SUN JAN 14 2007 VALID 161200Z - 171200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... NRN BRANCH OF POSITIVELY TILTED UPPER TROUGH IS FORECAST TO MOVE EAST THROUGH THE OH VALLEY AND THE NERN STATES TUESDAY LEAVING SRN BRANCH AS A CUTOFF UPPER LOW NEAR FOUR CORNERS REGION. COLD ARCTIC SURFACE HIGH PRESSURE WILL CONTINUE TO SPREAD SEWD OVER MUCH OF THE NATION. SWLY FLOW ALOFT DOWNSTREAM FROM UPPER TROUGH OVER THE SWRN STATES WILL MAINTAIN ISENTROPIC ASCENT AND AREAS OF PRECIPITATION OVER PARTS OF S TX. HOWEVER...GIVEN POOR LAPSE RATES...ANY ELEVATED INSTABILITY WILL BE VERY MARGINAL AND ANY CHANCE FOR LIGHTNING WITH THIS ACTIVITY SHOULD REMAIN LESS THAN 10%. ..DIAL.. 01/15/2007  From swody2 at goshenarc.org Tue Jan 16 04:59:34 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 15 Jan 2007 23:59:34 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 160502 SWODY2 SPC AC 160500 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1100 PM CST MON JAN 15 2007 VALID 171200Z - 181200Z ...NO TSTM AREAS FORECAST... ...DISCUSSION... COLD ARCTIC HIGH PRESSURE WITH OFFSHORE FLOW OVER THE GULF WILL PREVAIL OVER MUCH OF THE NATION THIS PERIOD. A SHORTWAVE TROUGH CURRENTLY OVER THE NERN PACIFIC WILL DROP SWD THROUGH CA WEDNESDAY. STEEP LAPSE RATES AND LIFT ACCOMPANYING THIS FEATURE MAY CONTRIBUTE TO A FEW SHOWERS ACROSS PARTS OF THE CNTRL OR SRN CA COASTAL AREAS. HOWEVER...AT THIS TIME COVERAGE OF ANY LIGHTNING ACTIVITY IS EXPECTED TO REMAIN LESS THAN 10%. ..DIAL.. 01/16/2007  From swody2 at goshenarc.org Fri Jan 19 06:31:50 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 19 Jan 2007 01:31:50 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 190634 SWODY2 SPC AC 190632 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1232 AM CST FRI JAN 19 2007 VALID 201200Z - 211200Z ...NO SVR TSTM AREAS FORECAST... ...ERN TX AND WRN LA... A SRN BRANCH UPPER LOW WILL EJECT ENEWD...REACHING THE SRN ROCKIES BY EARLY SATURDAY AND THE PLAINS SATURDAY NIGHT. PRIMARY SFC LOW WILL LIKELY REMAIN OVER THE HIGHER PLAINS...BUT A WEAK LOW WILL LIKELY FORM IN SERN TX AND SLOWLY LIFT NEWD SATURDAY NIGHT. SLY LLJ WILL STRENGTHEN SATURDAY ACROSS CNTRL TX AND TRANSLATE EWD SATURDAY NIGHT CONTRIBUTING TO INCREASING MOISTURE TRANSPORT. RECENT INTRUSION OF CP AIR MASS INTO THE WRN GULF BASIN WILL LIMIT MAGNITUDE OF THE MOISTURE RETURN AND LAPSE RATES ARE EXPECTED TO REMAIN WEAK. THUS...SEVERE WEATHER IS NOT A CONCERN. BUT...AS SRN PERIPHERY OF LARGER SCALE HEIGHT FALLS SPREAD ACROSS THE REGION...ISOLD TSTMS WILL BE POSSIBLE...PRIMARILY ACROSS ERN TX AND WRN LA. ..RACY.. 01/19/2007  From swody2 at goshenarc.org Fri Jan 19 17:02:21 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 19 Jan 2007 12:02:21 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 191704 SWODY2 SPC AC 191703 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1103 AM CST FRI JAN 19 2007 VALID 201200Z - 211200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS AND FORECAST... MID AND UPPER LEVEL LOW CURRENTLY MOVING ACROSS NRN BAJA CA IS FORECAST TO EJECT NEWD AS AN OPEN WAVE THROUGH THE SRN HIGH PLAINS INTO LOWER MO VALLEY IN RESPONSE TO DIGGING...UPSTREAM JET OVER THE PACIFIC NW INTO GREAT BASIN. IN THE LOW-LEVELS...SURFACE HIGH NOW BUILDING SEWD THROUGH THE SRN LOW PLAINS INTO LOWER MS VALLEY WILL BE SLOW TO ERODE WITH SOME WEAK BOUNDARY AND FRONTAL WAVE BECOMING BETTER DEFINED WITH TIME OVER E TX INTO THE LOWER MS VALLEY. THE EJECTING MID-LEVEL TROUGH WILL INDUCE LLJ DEVELOPMENT OVER E TX INTO THE LOWER MS VALLEY AND MID SOUTH...WITH A RESULTANT INCREASE IN MOIST/THERMAL ADVECTION ABOVE NEAR SURFACE INVERSION. LAPSE RATES WILL BE POOR IN THE MID-LEVELS WITH TEMPERATURE PROFILES REMAINING GENERALLY TOO WARM FOR CHARGE SEPARATION/LIGHTNING DEVELOPMENT. STILL...SOME POTENTIAL WILL EXIST FOR EMBEDDED POCKETS OF WEAK CONVECTIVE INSTABILITY WITHIN WARM CONVEYOR PRECIPITATION BAND WHICH COULD SUPPORT ISOLATED TSTM DEVELOPMENT. ..MEAD.. 01/19/2007  From swody2 at goshenarc.org Sat Jan 20 06:30:04 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 20 Jan 2007 01:30:04 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 200632 SWODY2 SPC AC 200630 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1230 AM CST SAT JAN 20 2007 VALID 211200Z - 221200Z ...NO SVR TSTM AREAS FORECAST... ...LWR MS VLY... UPPER LOW CURRENTLY OVER SRN AZ/NRN SONORA WILL EJECT ENEWD ACROSS THE PLAINS LATE TODAY AND INTO THE GREAT LAKES AS AN OPEN WAVE BY LATE SUNDAY. ATTENDANT FRONT WILL MOVE SEWD AND BE SITUATED FROM THE SRN APPALACHIANS TO THE WRN GULF COAST BY 12Z MON. MEANWHILE...A PIECE OF THE DISTURBANCE NOW OFF THE BC/WA COASTS WILL AMPLIFY AND DIG SWD THROUGH THE GRT BASIN ON SUNDAY. TIGHTENING HEIGHT GRADIENT DOWNSTREAM FROM THIS SYSTEM WILL CONTRIBUTE TO ACCELERATED FLOW WITHIN THE SUB-TROPICAL CONVEYOR. THIS JETSTREAM WILL BE IN PLACE FROM THE WRN GULF BASIN INTO THE DEEP S ATOP THE AFOREMENTIONED FRONT. THOUGH LAPSE RATES ARE GENERALLY EXPECTED TO BE MOIST ADIABATIC OR LESS...THE INCREASING FLOW ALOFT MAY PROVIDE SUFFICIENT FORCING FOR SOME PARCELS TO REACH INTO THE ICING LAYER FOR CHARGE SEPARATION ACROSS THE LWR MS VLY SUNDAY AFTN/NIGHT. NO ORGANIZED SVR TSTMS ARE ANTICIPATED OWING TO THE POOR LAPSE RATES AND MARGINAL GULF MSTR RETURN. ..RACY.. 01/20/2007  From swody2 at goshenarc.org Sat Jan 20 16:58:06 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 20 Jan 2007 11:58:06 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 201703 SWODY2 SPC AC 201701 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1101 AM CST SAT JAN 20 2007 VALID 211200Z - 221200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... MID AND UPPER LEVEL LOW CURRENTLY OVER NM IS FORECAST TO EVOLVE INTO AN OPEN WAVE AND DEAMPLIFY AS IT LIFTS NEWD THROUGH THE CNTRL/SRN PLAINS TODAY/TONIGHT AND INTO THE OH VALLEY SUNDAY. AS THIS OCCURS...DIGGING MID AND HIGH LEVEL JET STREAKS WILL CONTRIBUTE TO THE FORMATION OF UPSTREAM CLOSED LOW OVER THE SWRN DESERTS. IN THE LOW LEVELS...WEAKENING SURFACE LOW ATTENDANT TO DEAMPLIFYING WAVE WILL DEVELOP NEWD FROM CNTRL KS OR NWRN OK INTO THE OH VALLEY WITH TRAILING COLD FRONT PUSHING SWD THROUGH THE SRN PLAINS. MEANWHILE...SECONDARY LOW PRESSURE NOW OFF THE LOWER TX COAST WILL DEVELOP NEWD THROUGH THE LOWER MS VALLEY INTO SRN APPALACHIANS WITH TRAILING WEAK FRONT PUSHING EWD/SEWD THROUGH THE WRN/CNTRL GULF COAST. ...GULF COAST... SWLY LLJ /INDUCED BY WEAKENING WAVE LIFTING THROUGH THE OH VALLEY/ WILL SLOWLY MIGRATE EWD ACROSS THE REGION...SUPPORTING AN INCREASINGLY MOIST AIR MASS AHEAD OF LOWER LATITUDE SURFACE LOW AND ATTENDANT FRONT. THIS MOISTENING COUPLED WITH PERSISTENT ISENTROPIC ASCENT IS EXPECTED TO MAINTAIN A BAND OF SHOWERS WITH A FEW EMBEDDED TSTMS WITHIN PRE-FRONTAL AIR MASS. WHILE DEWPOINTS WILL INCREASE INTO THE LOW TO PERHAPS MID 60S ALONG AND S OF THE I-10 CORRIDOR...LAPSE RATES AND RESULTANT INSTABILITY WILL REMAIN QUITE WEAK. THEREFORE...DESPITE THE MODERATELY STRONG WIND FIELDS...NO SEVERE STORMS ARE FORECAST. ..MEAD.. 01/20/2007  From swody2 at goshenarc.org Sun Jan 21 06:35:23 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 21 Jan 2007 01:35:23 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 210640 SWODY2 SPC AC 210638 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1238 AM CST SUN JAN 21 2007 VALID 221200Z - 231200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... THE UPPER LEVEL DISTURBANCE OVER THE CNTRL PLAINS LATE SATURDAY EVE WILL WEAKEN AND SHEAR EWD THROUGH THE MIDWEST AND MID-ATLANTIC SUNDAY AND OUT INTO THE WRN ATLANTIC BASIN BY EARLY MONDAY. THE ATTENDANT SFC FRONT WILL SETTLE INTO THE SERN STATES AND NRN GULF COAST BY 12Z MONDAY AS CYCLOGENESIS OCCURS WELL EAST OF DELMARVA. UPPER JET ENERGY DIVING SEWD ACROSS BC WILL CONTRIBUTE TO AMPLIFICATION OF THE DOWNSTREAM ROCKIES TROUGH. PARTS OF THIS TROUGH WILL CUT-OFF FROM THE FLOW AND SETTLE SWD INTO NRN MEXICO ON MONDAY WHILE THE NRN STREAM PORTION DIGS SEWD INTO THE ERN PARTS OF THE COUNTRY. ...SRN GA/NRN FL,,, SFC LOW EVOLUTION ACROSS THE WRN ATLANTIC BASIN WILL CONTRIBUTE TO A DECIDEDLY WLY COMPONENT TO THE LOW-LEVEL FLOW REGIME ALONG/AHEAD OF THE COLD FRONT MONDAY AFTN/EVE. THIS WILL TEND TO LESSEN THE OVERALL MASS CONVERGENCE OVER THE SERN STATES VCNTY THE FRONT WITH TIME. MID-TROPOSPHERE WILL LIKELY REMAIN WARM BENEATH THE FLATTENING RIDGE AXIS...RESULTING IN THERMODYNAMIC PROFILES LESS CONDUCIVE FOR DEEP MOIST CONVECTION ACROSS CNTRL/SRN FL. FARTHER N...GLANCING INFLUENCE OF LARGER SCALE HEIGHT FALLS/ ASCENT...PRESENCE OF THE FRONT AND MODEST INCREASE IN BOUNDARY LAYER DEW POINTS MAY YIELD A COLUMN SUPPORTIVE FOR PARCELS TO REACH INTO THE ICING LAYER FOR CHARGE SEPARATION. HIGHEST PROBABILITY WILL BE THROUGH MID-AFTN AND MAINLY ACROSS EXTREME NRN/SRN PARTS OF FL/GA RESPECTIVELY. ...SERN AZ/SRN NM... ISOLD TSTMS MAY ACCOMPANY THE STEEPER MID-LEVEL LAPSE RATES ASSOCD WITH THE DIGGING CUT-OFF LOW EXPECTED TO MOVE INTO NRN MEXICO. STRONGER ASCENT SHOULD SHIFT S OF THE INTERNATIONAL BORDER VERY EARLY MONDAY. SLIGHTLY MORE FAVORABLE OROGRAPHICS/MOISTURE SHOULD RESIDE ACROSS NRN SONORA/CHIHUAHUA. AS A RESULT...TSTM PROBABILITIES SHOULD REMAIN LESS THAN 10 PERCENT ACROSS SERN AZ/SRN NM. ..RACY.. 01/21/2007  From swody2 at goshenarc.org Sun Jan 21 16:23:32 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 21 Jan 2007 11:23:32 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 211628 SWODY2 SPC AC 211627 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1027 AM CST SUN JAN 21 2007 VALID 221200Z - 231200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... EWD DEVELOPMENT OF POLAR BRANCH LONG WAVE TROUGH WILL OCCUR ACROSS THE NERN STATES INTO THE WRN ATLANTIC WHILE LOWER LATITUDE MID AND UPPER LEVEL LOW SLOWLY DRIFTS EWD ACROSS NRN MEXICO. IN THE LOW-LEVELS...SURFACE LOW INITIALLY OFF THE NC COAST MONDAY MORNING WILL DEVELOP NEWD INTO THE ATLANTIC WITH TRAILING COLD FRONT PUSHING SEWD THROUGH PORTIONS OF SC/GA INTO THE FL PENINSULA. ...SERN GA INTO THE NRN FL PENINSULA... DESPITE POOR LAPSE RATES...MOIST BOUNDARY LAYER CONDITIONS /DEWPOINTS IN THE MID 60S/ WILL CONTRIBUTE TO AN AXIS OF WEAK INSTABILITY /SBCAPES OF 300-400 J PER KG/ AHEAD OF COLD FRONT BY AFTERNOON. WEAK CAPPING COUPLED WITH FRONTAL CONVERGENCE SHOULD CONTRIBUTE TO AN INCREASE IN CONVECTIVE DEVELOPMENT THROUGH THE DAY. FORECAST SOUNDINGS SUGGEST THAT IN GENERAL MOST UPDRAFTS WILL REMAIN TOO SHALLOW/WARM FOR ICE DEVELOPMENT/CHARGE SEPARATION. HOWEVER...SOME OF THE STRONGER UPDRAFTS SHOULD BE SUPPORTIVE OF LIGHTNING DEVELOPMENT...MAINLY DURING THE AFTERNOON HOURS. ...SERN AZ/SWRN NM... CONSIDERABLY STEEPER LAPSE RATES /7-8 C PER KM/ WILL EXIST MONDAY INVOF UPPER LOW SLOWLY SHIFTING EWD ACROSS NRN MEXICO. WHILE MOST OF THE CONVECTIVE DEVELOPMENT ATTENDANT TO THIS SYSTEM WILL LIKELY REMAIN S OF THE INTERNATIONAL BORDER...A FEW LIGHTNING STRIKES WILL BE POSSIBLE OVER ADJACENT PORTIONS OF SERN AZ/SWRN NM. THIS THREAT APPEARS TOO MINIMAL TOO WARRANT INCLUSION OF AN ADDITIONAL THUNDER AREA. ..MEAD.. 01/21/2007  From swody2 at goshenarc.org Mon Jan 22 06:25:14 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 22 Jan 2007 01:25:14 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 220630 SWODY2 SPC AC 220628 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1228 AM CST MON JAN 22 2007 VALID 231200Z - 241200Z ...NO TSTM AREAS FORECAST... THE POLAR JET IS EXPECTED TO BECOME MORE ACTIVE THROUGH THE WEEK WITH AN INITIAL SHORTWAVE TROUGH MOVING FROM THE CNTRL PORTION OF THE COUNTRY TO OFF THE ERN SEABOARD BY TUE AFTN. THIS DISTURBANCE WILL FLATTEN THE LARGE UPPER RIDGE OVER THE SWRN ATLANTIC...WITH A COLD FRONT LIKELY MOVING THROUGH ALL OF FL AND THE CNTRL GULF OF MEXICO. THE INCREASING NWLY FLOW REGIME ACROSS THESE REGIONS WILL REINFORCE THE FLOW OF CONTINENTAL POLAR AIR WELL S AND PROSPECTS OF DEEP MOIST CONVECTION IS VERY LOW TO NIL OVER THE ERN STATES. MEANWHILE...AS THE WEST COAST RIDGE BUILDS NWD...THE CUT-OFF LOW MOVING INTO NRN MEXICO WILL REMAIN THERE. TSTMS ASSOCIATED WITH THIS SYSTEM SHOULD REMAIN SOUTH IN MEXICO WHERE STEEPER LAPSE RATES BECOME COINCIDENT WITH NWRN EDGE OF THE SUB-TROPICAL JET. ..RACY.. 01/22/2007  From swody2 at goshenarc.org Mon Jan 22 16:42:29 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 22 Jan 2007 11:42:29 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 221647 SWODY2 SPC AC 221645 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1045 AM CST MON JAN 22 2007 VALID 231200Z - 241200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... IN MID-UPPER LEVELS...NRN STREAM PATTERN WILL CONTINUE TO FEATURE SYNOPTIC TROUGH OVER HUDSON BAY AND GREAT LAKES REGIONS...WITH RIDGING OVER PACIFIC NW. PRONOUNCED MID-UPPER CYCLONE -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY AND RAOB ANALYSES OVER AZ/SONORA BORDER -- IS FCST TO BECOME CUT-OFF AND MEANDER ERRATICALLY ACROSS NWRN MEX THROUGH PERIOD. DOWNSTREAM WAA REGIME AND ELEVATED LOW LEVEL FRONTAL ZONE WILL CONTRIBUTE TO INCREASING COVERAGE OF PRECIP FROM N-CENTRAL MEX ACROSS LOWER RIO GRANDE VALLEY TO NWRN GULF. ISOLATED TSTMS MAY OCCUR OVER GULF...HOWEVER FCST SOUNDINGS INDICATE VERY WEAK LAPSE RATES -- PARTICULARLY IN HIGHER/COLDER LAYERS MOST FAVORABLE FOR LIGHTNING -- WILL PRECLUDE GEN TSTM RISK INLAND OVER S TX. ..EDWARDS.. 01/22/2007  From swody2 at goshenarc.org Sun Jan 28 05:52:50 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 28 Jan 2007 00:52:50 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 280557 SWODY2 SPC AC 280556 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1156 PM CST SAT JAN 27 2007 VALID 291200Z - 301200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... STRONG SHORT-WAVE TROUGH MOVING OFF THE MID-ATLANTIC/NEW ENGLAND COAST AT THE START OF THE PERIOD WILL CONTINUE MOVING INTO THE ATLANTIC...WHILE LARGE-SCALE TROUGH REMAINS OVER THE ERN 2/3 OF THE CONUS. MEANWHILE...REX BLOCK WILL PERSIST OVER THE ERN PACIFIC/WRN NOAM. AT THE SURFACE...FRONT S OF FL/THE KEYS WILL CONTINUE MOVING SWD...WHILE HIGH PRESSURE SETTLES SEWD ACROSS THE GULF COAST REGION. WITH MOIST BOUNDARY LAYER SUPPRESSED WELL S OF THE CONUS AND COOL/CONTINENTAL AIRMASS IN PLACE E OF THE ROCKIES...THUNDERSTORMS ARE NOT ANTICIPATED THIS PERIOD. ..GOSS.. 01/28/2007  From swody2 at goshenarc.org Sun Jan 28 17:24:05 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 28 Jan 2007 12:24:05 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 281728 SWODY2 SPC AC 281727 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1127 AM CST SUN JAN 28 2007 VALID 291200Z - 301200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS/FORECAST... ALTHOUGH UPPER RIDGE OVER THE NERN PACIFIC IS EXPECTED TO STRENGTHEN DURING DAY 2 PERIOD...CLOSED LOW RETROGRADING OFF THE CA COAST TODAY IS EXPECTED TO MOVE SSEWD TOWARD THE SRN CA COAST ON MONDAY RESULTING IN A BREAK DOWN OF THE REX BLOCK. DOWNSTREAM LONG WAVE TROUGH OVER THE ERN TWO-THIRDS OF THE U.S. WILL BE MAINTAINED AS ANOTHER SHORT WAVE TROUGH TRACKS SEWD INTO THE MID MS/OH VALLEYS. COLD FRONT WILL CONTINUE TO MOVE WELL S OF THE CONTINENTAL U.S. AS HIGH PRESSURE SETTLES SWD ACROSS THE GULF COAST AND GULF OF MEXICO. SLY LOW LEVEL FLOW IS EXPECTED TO INCREASE ALONG AND OFF THE S TX COAST IN RESPONSE TO WEAK HEIGHT FALLS AS A PACIFIC SHORT WAVE TROUGH...NOW LOCATED NEAR 20N 132W...TRACKS EWD ACROSS NRN MEXICO TO SRN TX. WRN EXTENT OF COLD FRONT WILL LIKELY REDEVELOP NWD INTO A COASTAL TROUGH OVER THE WRN GULF BASIN BY MONDAY NIGHT. WEAK LOW LEVEL WAA AND MOISTURE RETURN SHOULD SUPPORT SHALLOW CONVECTION MAINLY OFFSHORE LATE IN THE PERIOD...WITH POINT FORECAST SOUNDINGS SUGGESTING CLOUD DEPTHS NOT BECOMING DEEP ENOUGH FOR CHARGE SEPARATION/LIGHTNING PRODUCTION. ELSEWHERE...A FEW LIGHTNING STRIKES MAY DEVELOP OFF THE SRN COAST... ESPECIALLY LATER IN THE FORECAST PERIOD...AS STEEPER LAPSE RATES AND INCREASING ASCENT ACCOMPANYING THE WEST COAST UPPER LOW APPROACH THIS REGION. ..PETERS.. 01/28/2007  From swody2 at goshenarc.org Mon Jan 29 06:34:53 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 29 Jan 2007 01:34:53 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 290639 SWODY2 SPC AC 290638 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1238 AM CST MON JAN 29 2007 VALID 301200Z - 311200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... CHANGES ARE FORECAST WITH THE UPPER PATTERN THIS PERIOD...AS TWO PRONOUNCED SMALLER-SCALE PERTURBATIONS PROGRESS THROUGH THE ERN U.S. MEAN TROUGH AND THE W COAST REX BLOCK BREAKS DOWN. THE BREAKDOWN OF THE REX BLOCK WILL BE THE ONLY CHANGE OF ANY SIGNIFICANCE WITH RESPECT TO THUNDERSTORM POTENTIAL -- AS STEEPER LAPSE RATES OVER AZ ASSOCIATED WITH THE SEWD APPROACH OF THE UPPER LOW MAY RESULT IN MINIMAL CAPE. THOUGH POSSIBLY SUFFICIENT FOR A FEW ISOLATED LIGHTNING STRIKES...IT APPEARS ATTM THAT OVERALL LIGHTNING COVERAGE SHOULD REMAIN SUFFICIENTLY LOW TO PRECLUDE THE ISSUANCE OF AN OUTLOOK AREA ATTM. ELSEWHERE ACROSS THE CONUS...THUNDERSTORMS ARE NOT ANTICIPATED. ..GOSS.. 01/29/2007  From swody2 at goshenarc.org Wed Jan 3 17:22:05 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Wed, 03 Jan 2007 12:22:05 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 031726 SWODY2 SPC AC 031724 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1124 AM CST WED JAN 03 2007 VALID 041200Z - 051200Z ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS SE TX TO EXTREME SERN MS.... ...SYNOPSIS... PRONOUNCED MID/UPPER LEVEL CYCLONE IS EVIDENT IN MOISTURE CHANNEL IMAGERY OVER NWRN MEX. THIS SYSTEM IS EXPECTED TO EJECT ENEWD THEN EWD ACROSS WRN/CENTRAL TX...REACHING E TX OR VICINITY TX/LA BORDER AROUND 4/12Z BASED ON LATEST OPERATIONAL SPECTRAL/ETA FCST...AS WELL AS CONSENSUS OF 3/09Z ENSEMBLE RUNS. THIS WILL BE FOLLOWED BY HEIGHT FALLS ACROSS MUCH OF WRN CONUS...AS HIGH-AMPLITUDE/POSITIVELY-TILTED TROUGH EVOLVES FROM PERTURBATIONS NOW OVER N-CENTRAL PACIFIC. LOW LEVEL FRONTAL ZONE IS EVIDENT ATTM OVER CENTRAL/NRN GULF...WITH SFC BOUNDARY ROUGHLY LOCATED FROM VERACRUZ NWD TO ABOUT 100 NM SE BRO...THEN EWD TOWARD BUOY 42003...THEN ACROSS S-CENTRAL FL. AS MEX UPPER LOW APCHS...FRONTAL-WAVE LOW IS EXPECTED TO DEVELOP ALONG INFLECTION POINT OF SFC FRONTAL ZONE...OVER NWRN GULF. THIS LOW SHOULD MOVE NEWD ACROSS NWRN GULF AND ONSHORE BPT-LCH VICINITY EARLY IN PERIOD...HOWEVER POSITIONING/STRENGTH OF LOW WILL DEPEND STRONGLY ON MESOSCALE FACTORS INCLUDING PRECIP-RELATED MODULATION OF FRONTAL ZONE IN W GULF AREA. STRONGEST ASSOCIATED PRESSURE FALLS SHOULD MOVE NEWD INTO PROGRESSIVELY COLDER AND MORE STABLE AIR...LEAVING WAVY SFC FRONTAL ZONE LOCATED ACROSS SERN LA LATE IN PERIOD. ...W GULF COASTAL PLAIN TO MS DELTA... SCATTERED-NUMEROUS TSTMS ARE POSSIBLE THROUGHOUT PERIOD...SHIFTING GENERALLY EWD ACROSS REGION. ACTIVITY WILL OCCUR IN ENVIRONMENT OF STRONG VERTICAL SHEAR SUPPORTING SUPERCELLULAR MODE FOR DISCRETE STORMS AND BOWS/LEWPS WITHIN ANY LINES. INITIALLY ELEVATED AREA OF TSTMS LATE-DAY1 ACROSS S TX -- WITH MRGL HAIL THREAT -- MAY MOVE EWD FAST ENOUGH TO REACH WARM SECTOR AND BECOME SFC-BASED ACROSS SRN LA DURING THIS PERIOD. ADDITIONALLY...SEPARATE DEVELOPMENT IS POSSIBLE IN WEAKLY CAPPED MARINE AIR MASS THAT WILL BE CHARACTERIZED BY EFFECTIVE PARCELS ROOTED AT SFC AND DEW POINTS 60S F. EXPECT SFC THETAE TO OFFSET WEAK MIDLEVEL LAPSE RATES ENOUGH TO YIELD MLCAPES TO AROUND 1000 J/KG BY AFTERNOON. SLY/SELY SFC WINDS ALSO SHOULD BE COMMON ALONG AND S OF MARINE/WARM FRONT...CONTRIBUTING TO ENLARGED LOW LEVEL HODOGRAPHS. PRIMARY UNCERTAINTIES FOR SVR POTENTIAL INVOLVE COVERAGE OF INLAND PENETRATION OF MOST FAVORABLE WARM SECTOR AIR MASS...WITH GREATEST SVR PROBABILITIES NEAR COAST WHERE WARM/MARINE FRONT IS MOST LIKELY TO PENETRATE INLAND. ..EDWARDS.. 01/03/2007  From swody2 at goshenarc.org Thu Jan 4 05:59:48 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 04 Jan 2007 00:59:48 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 040604 SWODY2 SPC AC 040603 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1203 AM CST THU JAN 04 2007 VALID 051200Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM NRN FL TO SRN NC... ...SERN U.S... MODELS ARE IN MUCH BETTER AGREEMENT TONIGHT REGARDING THE EJECTING UPPER LOW ALONG THE GULF COAST OVER THE NEXT FEW DAYS. WITH TIME THIS FEATURE WILL DEAMPLIFY AS IT APPROACHES THE CAROLINAS...ALTHOUGH MID-HIGH LEVEL FLOW WILL CERTAINLY ENHANCE DEEP LAYER SHEAR/ORGANIZATIONAL POTENTIAL FOR CONVECTION THAT DEVELOPS AHEAD OF THE TROUGH. EARLIER CONCERNS OF LIMITED MOISTURE RETURN AHEAD OF RAPIDLY WEAKENING SFC FRONT HAVE SUBSIDED AS IT NOW APPEARS SFC DEW POINTS OF AT LEAST LOW-MID 60S SHOULD SPREAD INLAND WELL AHEAD OF WIND SHIFT/CONVECTIVE OUTFLOW...WITH HIGHER VALUES POSSIBLE NEAR THE GULF COAST. LATEST THINKING IS A CONSIDERABLE AMOUNT OF STRONGLY FORCED CONVECTION SHOULD BE ONGOING AT THE BEGINNING OF THE PERIOD OVER AL/FL PANHANDLE. THIS ACTIVITY SHOULD PROPAGATE EWD ACROSS THE REMAINDER OF NRN FL PENINSULA...AND SRN GA BY 00Z AS WELL DEFINED SHORTWAVE ENHANCES VERTICAL MOTION FIELD. ADDITIONALLY...IT APPEARS BOUNDARY LAYER HEATING MAY CONTRIBUTE SUBSTANTIALLY TO DESTABILIZATION AS LAPSE RATES STEEPEN AHEAD OF MAIN CONVECTIVE LINE. IT APPEARS SUFFICIENT RECOVERY WILL OCCUR ACROSS THE COASTAL CAROLINAS FOR STRONG/SEVERE CONVECTION AFTER 00Z. SHEAR PROFILES CERTAINLY SUPPORT THE POTENTIAL FOR SUPERCELLS...HOWEVER DOMINANT STORM MODE MAY ACTUALLY BE LINEAR GIVEN THE LIKELIHOOD OF PROGRESSIVE SQUALL LINE. IF SQUALL LINE IS THE DOMINANT MODE...DAMAGING WINDS SHOULD BE THE PRIMARY SEVERE THREAT. ..DARROW.. 01/04/2007  From swody2 at goshenarc.org Thu Jan 4 16:57:10 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Thu, 04 Jan 2007 11:57:10 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 041701 SWODY2 SPC AC 041700 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1100 AM CST THU JAN 04 2007 VALID 051200Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE SERN STATES... ...SERN STATES... THE CNTRL TX UPR LOW WILL EJECT ENEWD ACROSS THE WRN GULF COASTAL STATES TONIGHT THENCE DEAMPLIFY AND TRAVERSE THE SERN STATES AND SRN APPALACHIAN REGION DURING FRIDAY AND FRIDAY NIGHT. THE WEAKENING PHASE OF THIS WAVE WILL RESULT IN SFC FEATURES THAT BECOME LESS DEFINED DURING THE DAY WITH PERSISTENT RIDGING LIKELY OVER THE VAST MAJORITY OF THE SE COAST PER 12Z GFS. BELT OF ENHANCED LOW- AND MID-LEVEL FLOW BETWEEN THE ATLANTIC RIDGE AND THE UPSTREAM IMPULSE WILL ADVECT A HIGHER THETA-E AIR MASS NWD INTO NRN FL...SRN GA AND PARTS OF THE CAROLINAS TODAY AND FRIDAY. HEATING OF THIS AIR MASS WILL CONTRIBUTE TO DESTABILIZATION...WITH STRONGEST INSTABILITY LIKELY RELEGATED TO THE CNTRL/ERN FL PNHDL INTO NRN FL AND SRN GA DURING THE AFTN. A LINEAR MCS SHOULD BE ONGOING AT 12Z FRIDAY ACROSS CNTRL/SRN AL SWWD INTO THE NCNTRL GULF OF MEXICO. OVERALL STRUCTURE OF THE SQUALL LINE MAY TEND TO BECOME DISORGANIZED AND WEAKEN FRIDAY MORNING AS UPPER SUPPORT WEAKENS. CONVECTIVE OUTFLOWS...HOWEVER... MAY BE IMPETUS FOR ADDITIONAL STORMS /OR RE-INTENSIFICATION OF MORNING ACTIVITY/ DOWNSTREAM IN THE UNSTABLE ENVIRONMENT FRIDAY AFTN. THOUGH THE UPPER SYSTEM WILL WEAKEN WITH TIME...PRESENCE OF 50-70 KTS OF H5 FLOW WILL ENHANCE THE DEEP LAYER SHEAR SUFFICIENTLY FOR POSSIBLE SUPERCELLS. THIS WILL ESPECIALLY BE THE CASE WHERE BUOYANCY IS STRONGER IN THE FL PNHDL AND SRN GA. ACTIVITY SHOULD REMAIN ESSENTIALLY LINEAR...THOUGH...WITH A PRIMARY WIND DAMAGE THREAT AS ACTIVITY MOVES ENEWD ACROSS SRN GA AND NRN FL INTO PARTS OF THE CAROLINAS BY 00-03Z. ISOLD TORNADOES CANNOT BE RULED OUT WHERE MORE ROBUST TSTMS CAN DEVELOP. ..RACY.. 01/04/2007  From swody2 at goshenarc.org Fri Jan 5 06:15:10 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 05 Jan 2007 01:15:10 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 050619 SWODY2 SPC AC 050617 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1217 AM CST FRI JAN 05 2007 VALID 061200Z - 071200Z ...NO SVR TSTM AREAS FORECAST... A STRONG NORTHERN STREAM JET STREAK OVER THE NORTHERN PACIFIC IS NOSING TOWARD THE BRITISH COLUMBIA/PACIFIC NORTHWEST COAST... AND PROGGED TO CONTINUE EASTWARD...INLAND AND ACROSS THE CANADIAN/ NORTHERN AND CENTRAL U.S. ROCKIES LATER TODAY THROUGH SATURDAY/ SATURDAY NIGHT. AS THIS OCCURS...THE COMPLEX SPLIT UPPER FLOW PATTERN CURRENTLY IN PLACE ACROSS MUCH OF THE NATION IS FORECAST TO BEGIN CONSOLIDATING INTO A BROAD LARGE-SCALE TROUGH...WHICH WILL ENCOMPASS MOST AREAS EAST OF THE ROCKIES BY 12Z SUNDAY. THE EXCEPTION WILL BE THE SOUTHEAST...WHERE UPPER RIDGING WILL BUILD ONCE AGAIN SATURDAY IN THE WAKE OF REMNANTS OF A WEAKENING CLOSED LOW...NOW BEGINNING TO LIFT OUT OF THE SOUTH CENTRAL STATES. MODELS INDICATE THAT AN UPSTREAM IMPULSE WILL LIFT OUT OF THE SOUTHERN ROCKIES IN A POSITIVELY TILTED FASHION BY EARLY SATURDAY...TRAILING A MORE VIGOROUS NORTHERN BRANCH SHORT WAVE...WHICH IS PROGGED TO RAPIDLY LIFT FROM THE UPPER MISSISSIPPI VALLEY THROUGH THE ST. LAWRENCE VALLEY AND NORTHEAST BY EARLY SUNDAY. SOUTHERN SYSTEM APPEARS LIKELY TO BECOME INCREASINGLY SHEARED ACROSS THE LOWER MISSISSIPPI VALLEY AS IT APPROACHES THE UPPER RIDGE AXIS...WHILE ANOTHER MUCH STRONGER NORTHERN STREAM SHORT WAVE DIGS EAST OF THE ROCKIES INTO THE NORTH CENTRAL STATES. IN RESPONSE TO THE EVOLVING UPPER PATTERN...MODELS INDICATE A SURFACE LOW WILL DEEPEN AS IT LIFTS THROUGH THE ST. LAWRENCE VALLEY. THIS WILL FORCE THE PRIMARY SURFACE COLD FRONT EAST OF THE OHIO VALLEY AND OFF THE NORTH ATLANTIC COAST STATES BY EARLY SUNDAY. BUT...THIS BOUNDARY IS EXPECTED TO BE MUCH SLOWER TO PROGRESS EAST OF THE TENNESSEE VALLEY AND CENTRAL/EASTERN GULF STATES. ...NORTHERN ATLANTIC COAST... MODELS SUGGEST WEAK INSTABILITY WILL BE PRESENT IN AN AREA OF FOCUSED LOW-LEVEL WARM ADVECTION TO THE EAST OF THE DEEPENING SURFACE LOW...MAINLY NEAR SOUTHERN NEW ENGLAND COASTAL AREAS EARLY SATURDAY. THIS MAY BE SUFFICIENT TO CONTRIBUTE TO SCATTERED WEAK THUNDERSTORM ACTIVITY...BEFORE STRONGER FORCING SHIFTS WELL EAST OF COASTAL AREAS BY SATURDAY AFTERNOON. ...CNTRL/ERN GULF STATES AND TENNESSEE VALLEY... ANY SUPPRESSION OF MOISTURE LEVELS IN THE WAKE OF LEAD WEAKENING SOUTHERN BRANCH IMPULSE IS EXPECTED TO BE RELATIVELY MINOR/ SHORT-LIVED. HOWEVER...LAPSE RATES WILL BE WEAK...AND THIS IS LIKELY TO MINIMIZE CAPE ALONG/AHEAD...AND IN THE WAKE...OF SURFACE COLD FRONT AS IT SLOWLY ADVANCES EASTWARD ACROSS REGION. STRONGER FORCING FOR UPWARD VERTICAL MOTION WILL PROBABLY BE CONFINED TO A POST-FRONTAL BAND LATE IN THE PERIOD...FROM NORTHERN MISSISSIPPI THROUGH THE UPPER TENNESSEE VALLEY...WHERE BEST CHANCE FOR STORMS MAY EXIST. GIVEN THERMODYNAMIC ENVIRONMENT...HAIL POTENTIAL SEEMS REMOTE...AND EVEN IF A FEW STORMS DO DEVELOP IN THE PRE-FRONTAL REGIME...ISOLATED TORNADO/DAMAGING WIND POTENTIAL SEEMS NEGLIGIBLE DUE TO ANTICIPATED WEAK LOW-LEVEL FLOW/SMALL LOW-LEVEL HODOGRAPHS. ..KERR.. 01/05/2007  From swody2 at goshenarc.org Fri Jan 5 17:08:51 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 05 Jan 2007 12:08:51 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 051712 SWODY2 SPC AC 051710 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1110 AM CST FRI JAN 05 2007 VALID 061200Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...LWR MS VLY AND MID-SOUTH INTO THE SERN STATES... UPPER LOW MOVING ACROSS THE REGION TODAY WILL MOVE WELL OUT TO SEA BY SATURDAY. IN WAKE OF THIS SYSTEM...THE SURFACE COLD FRONT IS EXPECTED TO DECELERATE ACROSS NRN FL AND THE NRN GULF BASIN TONIGHT...THEN BEGIN LIFTING NWD SATURDAY AND SATURDAY NIGHT. UPSTREAM...A POSITIVE-TILT TROUGH WAS DIGGING SEWD THROUGH THE GREAT BASIN. SRN PORTION OF THIS TROUGH WILL LIKELY BEGIN TO SHEAR ACROSS THE MID-SOUTH ON SATURDAY...OWING TO THE MODEST UPPER RIDGE ACROSS THE SWRN ATLANTIC BASIN. THE COLD FRONT ACCOMPANYING THIS SYSTEM WILL BEGIN TO MOVE SEWD ACROSS THE TN AND LWR MS RVR VLYS SATURDAY NIGHT. RETURN FLOW WILL COMMENCE LATER TONIGHT ACROSS THE DEEP SOUTH AHEAD OF THE UPSTREAM WAVE/FRONT. LOW-LEVEL MOISTURE WILL ADVECT NWD...BUT A WARM/SUBSIDENT LAYER ALOFT BEHIND THE DEPARTING IMPULSE WILL LIKELY FAVOR SHALLOW CONVECTIVE CLOUDS AND LITTLE THUNDER THROUGH PEAK HEATING. CONVECTION IS LIKELY TO INCREASE/INTENSIFY... HOWEVER...SATURDAY NIGHT WITHIN THE INCREASING LOW- AND MID-LEVEL WARM/MOIST ADVECTION REGIME. TSTMS WILL BECOME MORE LIKELY AFTER 06Z...ESPECIALLY DOWNSTREAM FROM STRONGER HEIGHT FALLS AND ALONG/N OF THE COLD FRONT ACROSS ERN LA NWD INTO THE MID-SOUTH. ISOLD TSTMS MAY ALSO EVOLVE DOWNSTREAM AHEAD OF THE FRONT BY 12Z SUNDAY AS THE COLUMN GRADUALLY MOISTENS AND DESTABILIZES. SEVERE TSTM PROBABILITIES WILL LIKELY BE NEGLIGIBLE GIVEN POOR LAPSE RATES... MINIMAL INSTABILITY AND WEAK LOW-LEVEL FLOW. ...SERN NEW ENGLAND... A LOW PROBABILITY OF ISOLD TSTMS WILL EXIST BEFORE 18Z SATURDAY. SRN PERIPHERY OF WEAK H5 HEIGHT FALLS ASSOCD WITH A NRN STREAM WAVE WILL TRANSLATE ACROSS THE REGION EARLY IN THE DAY. FORECAST SOUNDINGS INDICATE THAT ELEVATED PARCELS WILL LIKELY BE LOFTED INTO THE ICING LAYER WITH MUCAPES OF 100-200 J/KG...INCREASING THE RISK FOR LIGHTNING. ..RACY.. 01/05/2007  From swody2 at goshenarc.org Sat Jan 6 05:40:11 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 06 Jan 2007 00:40:11 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 060544 SWODY2 SPC AC 060543 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1143 PM CST FRI JAN 05 2007 VALID 071200Z - 081200Z ...THERE IS A SLGT RISK OF SVR TSTMS LATE SUN AFTN/SUN NIGHT ACROSS PARTS OF THE SRN MID ATLANTIC COAST STATES.... IMPULSES EMBEDDED WITHIN COMPLEX SPLIT UPPER FLOW PATTERN STILL APPEAR LIKELY TO CONSOLIDATE INTO AN AMPLIFIED LARGE-SCALE TROUGH ENCOMPASSING MUCH OF THE CENTRAL/EASTERN STATES BY THE END OF THIS FORECAST PERIOD. THE PRIMARY IMPULSE EXPECTED TO SUPPORT THIS DEVELOPMENT IS READILY EVIDENT IN LATEST WATER VAPOR IMAGERY... DIGGING ACROSS THE NORTHWESTERN U.S...WITHIN THE NORTHERN BRANCH OF THE POLAR WESTERLIES. THE COLD...VIGOROUS SHORT WAVE TROUGH IS PROGGED TO CONTINUE TO DIG TO THE LEE OF THE ROCKIES...THROUGH THE NORTHERN AND CENTRAL PLAINS BY MIDDAY SUNDAY...BEFORE TURNING EASTWARD ACROSS THE UPPER HALF OF THE MISSISSIPPI VALLEY/THE OHIO VALLEY AND GREAT LAKES REGION BY 12Z MONDAY. AS THIS OCCURS... MODELS INDICATE THAT THE LARGER SCALE TROUGH WILL TAKE ON AN INCREASINGLY NEGATIVE TILT...ACCOMPANIED BY STRONG SURFACE CYCLOGENESIS FROM THE LEE OF THE APPALACHIANS THROUGH THE NORTH ATLANTIC COAST. ...SOUTHERN/MID ATLANTIC COAST STATES... MODELS SUGGEST THAT MODIFICATION OF BOUNDARY LAYER OVER THE NORTH CENTRAL GULF OF MEXICO...AND RETURN FLOW INTO THE SOUTHEASTERN STATES...WILL BE RAPID IN THE WAKE OF A WEAKENING LEAD SOUTHERN BRANCH SHORT WAVE TROUGH...NOW RAPIDLY LIFTING INTO/THROUGH THE SOUTH ATLANTIC COAST REGION. HOWEVER...COLDER AIR ALOFT...LAGGING WELL TO THE NORTH/WEST...IS NOT PROGGED TO OVERSPREAD RETURNING MOISTURE...AND LAPSE RATES WILL REMAIN WEAK IN EVOLVING WARM SECTOR THROUGH THIS FORECAST PERIOD. THIS WILL TEND TO MINIMIZE CAPE...AND MAY TEMPER SEVERE POTENTIAL ACROSS THE SOUTHEAST SUNDAY/SUNDAY NIGHT. STILL...A RISK OF SEVERE STORMS IS SUPPORTED BY ANTICIPATED FORCING FOR UPWARD VERTICAL MOTION ASSOCIATED WITH RAPID DEEPENING OF SURFACE LOW...WHICH MODELS INDICATE WILL COMMENCE TO THE LEE OF THE SOUTHERN APPALACHIANS SUNDAY EVENING. THIS WILL BE ACCOMPANIED BY STRENGTHENING LOW-LEVEL FLOW FIELDS...LIKELY INCLUDING A 50-70 KT SOUTHERLY LOW-LEVEL JET FROM THE CAROLINAS THROUGH THE DELMARVA PENINSULA BY LATE SUNDAY EVENING. INFLUX OF MOISTENING BOUNDARY LAYER OFF THE SOUTH ATLANTIC APPEARS LIKELY ACROSS AT LEAST THE COASTAL PLAIN OF EASTERN NORTHERN CAROLINA...WHERE LOW-LEVEL HODOGRAPHS TO THE EAST OF DEVELOPING CYCLONE WILL BE LARGE AND FAVORABLE FOR ISOLATED SUPERCELLS WITH TORNADOES. AS SURFACE LOW DEVELOPS INTO/OFF MID ATLANTIC COASTAL AREAS LATER SUNDAY NIGHT...A CONVECTIVE BAND...ACCOMPANYING EASTWARD SURGING COLD FRONT TO ITS SOUTH...COULD ENHANCE DOWNWARD MOMENTUM TRANSFER ACROSS THE SOUTHERN MID ATLANTIC COAST. ..KERR.. 01/06/2007  From swody2 at goshenarc.org Sat Jan 6 17:20:38 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 06 Jan 2007 12:20:38 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 061724 SWODY2 SPC AC 061722 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1122 AM CST SAT JAN 06 2007 VALID 071200Z - 081200Z ...THERE IS A SLGT RISK OF SVR TSTMS LATE SUN AFTN/SUN NIGHT OVER PARTS OF THE SRN MID ATLANTIC COAST STATES... ...DEEP SOUTH TO THE SRN MID-ATLANTIC REGION... 140+ KT H25 JET DIGGING SWD ALONG THE PAC NW COAST THIS MORNING WILL ENHANCE THE WAVE OVER THE NRN ROCKIES TODAY. THIS SHORTWAVE TROUGH WILL THEN DIG SEWD INTO THE CNTRL/NRN PLAINS AND BECOME MORE NEGATIVELY TILTED BEFORE MOVING INTO THE UPPER MIDWEST BY 12Z MONDAY. AHEAD OF THIS SYSTEM...THE FRONT SITUATED ALONG THE NRN GULF BASIN TODAY WILL RAPIDLY DEVELOP NWD ACROSS THE SERN STATES AND INTO THE MID-ATLANTIC REGION SUNDAY AND SUNDAY NIGHT. CYCLOGENESIS WILL TAKE PLACE LATE TONIGHT VCNTY SRN LA COAST. THIS LOW WILL THEN TRANSLATE NEWD TO THE WEST OF THE APPALACHIAN MOUNTAIN CHAIN ON SUNDAY WITH PERHAPS A WEAK LOW FORMING OVER DELMARVA BY EARLY MONDAY. TRAILING THE LOW...A COLD FRONT WILL SWEEP EWD FROM THE LWR MS VLY TO A POSITION FROM CNTRL VA SWWD TO SERN GA AND NRN FL BY MONDAY MORNING. 12Z RAOBS EXHIBITED POOR LAPSE RATES ACROSS THE DEEP S AND SERN STATES OWING TO WARM TROPOSPHERIC TEMPERATURES ASSOCIATED WITH THE DEEP LAYER RIDGE OVER THE AREA. BOUNDARY LAYER MOISTURE WILL RAPIDLY RETURN NWD AHEAD OF THE NEXT IMPULSE WITH LWR-MID 60S SFC DEW POINTS LIKELY COMMON ACROSS THE SERN STATES AND SRN MID-ATLANTIC REGION BY SUNDAY NIGHT. THERMAL BUOYANCY WILL LIKELY BE MITIGATED BY THE CONTINUED POOR LAPSE RATES ALOFT...HOWEVER. 12Z NAM/GFS AGREE THAT AN INCREASING LLJ WILL ENHANCE THETA-E ADVECTION IN THE LEE OF THE APPALACHIANS SUNDAY EVE. THIS SHOULD SUPPORT INCREASING CONVECTION/TSTMS THAT WILL MOVE NWD FROM SERN GA TO THE SRN MID-ATLANTIC SUNDAY AFTN/NIGHT. THOUGH INSTABILITY WILL BE MINIMAL...LOW-LEVEL HODOGRAPHS EXHIBIT STRONG VEERING WITH HEIGHT AMIDST A MOISTENING BOUNDARY LAYER. AS A RESULT...BRIEF TORNADOES CANNOT BE RULED OUT WITH MORE SUSTAINED STORMS... ESPECIALLY OVER THE COASTAL PLAINS OF SC...NC AND SERN VA. OTHERWISE...A LOOSELY ORGANIZED LINEAR MCS SHOULD GRADUALLY EVOLVE ALONG THE COLD FRONT SUNDAY AFTN AND NIGHT AS STRONGER LARGE SCALE HEIGHT FALLS ASSOCD WITH THE APPROACHING TROUGH SPREAD EWD. STEEPEST MID-TROPOSPHERIC LAPSE RATES WILL PASS THROUGH THE OH VLY. THUS...INSTABILITY WILL PROBABLY REMAIN RATHER MEAGER ALONG THE FRONT. BUT...ENHANCED FLOW ALOFT AND INCREASING CROSS-COMPONENT FLOW WITH RESPECT TO THE COLD FRONT ALONG THE BASE OF THE UPPER TROUGH SUGGEST THAT ISOLD TSTMS MAY BOW...INCREASING THE RISK OF A DAMAGING WIND GUST OR BRIEF TORNADO ACROSS THE DEEP SOUTH AND PARTS OF THE SERN STATES SUNDAY AFTN/NIGHT. ..RACY.. 01/06/2007  From swody2 at goshenarc.org Sun Jan 7 05:45:32 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 07 Jan 2007 00:45:32 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 070549 SWODY2 SPC AC 070548 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1148 PM CST SAT JAN 06 2007 VALID 081200Z - 091200Z ...NO SVR TSTM AREAS FORECAST... MODELS INDICATE THAT THE AMPLIFIED POLAR TROUGH...DEVELOPING OVER THE CENTRAL/EASTERN U.S. TODAY...WILL PERSIST THROUGH THIS FORECAST PERIOD. THE MOST VIGOROUS EMBEDDED IMPULSE IS PROGGED TO LIFT RAPIDLY OUT OF THE LOWER GREAT LAKES/OHIO VALLEY INTO THE CANADIAN MARITIMES BY 12Z TUESDAY. BUT...THIS IS PROGGED TO OCCUR AS ANOTHER SIGNIFICANT SHORT WAVE TROUGH DIGS THROUGH THE MISSOURI VALLEY. FARTHER UPSTREAM...ANOTHER LARGE COLD UPPER TROUGH LIKELY WILL DIG ACROSS THE NORTHEAST PACIFIC...TOWARD THE BRITISH COLUMBIA /NORTHERN U.S. PACIFIC COAST. STABILIZATION ASSOCIATED WITH A COLD FRONT AND REINFORCING COLD SURGE ACCOMPANYING THE EASTERN TROUGH IS EXPECTED TO PRECLUDE CONVECTIVE POTENTIAL ACROSS MUCH OF THE NATION MONDAY/MONDAY NIGHT. HOWEVER...THE LOW/MID-LEVEL FRONTAL ZONE MAY STILL BE INLAND OF ATLANTIC COASTAL AREAS EARLY IN THE PERIOD. THIS WILL MAINTAIN AT LEAST A LOW PROBABILITY OF THUNDERSTORMS FROM PARTS OF THE SOUTHERN MID ATLANTIC COAST INTO NEW ENGLAND THROUGH MONDAY MORNING...BUT THE RISK LIKELY WILL END BY MID DAY AS THE FRONT FINALLY ADVANCES OFFSHORE. THE BOUNDARY MAY NOT CLEAR THE SOUTHERN FLORIDA PENINSULA UNTIL EARLY MONDAY EVENING...BUT MID-LEVEL INHIBITION IN FORECAST SOUNDINGS APPEARS TOO STRONG FOR AN APPRECIABLE RISK OF THUNDERSTORMS...GIVEN WEAK UPPER FORCING ACROSS THIS REGION. ...MID ATLANTIC COAST... BETTER LOW-LEVEL MOISTURE ALONG PROGGED INTENSE PRE-FRONTAL SOUTHERLY LOW-LEVEL JET AXIS MAY ALREADY BE OFFSHORE BY 12Z MONDAY. AND...PRE-FRONTAL SURFACE FLOW MAY BE IN THE PROCESS OF VEERING. HOWEVER...THE FRONT MAY STILL CONTRIBUTE TO SUFFICIENT FORCING FOR AT LEAST A WEAK CONVECTIVE BAND...WHICH MAY ENHANCE DAMAGING WIND POTENTIAL VIA DOWNWARD TRANSFER OF MOMENTUM ASSOCIATED WITH 50+ KT MEAN ENVIRONMENTAL FLOW. THREAT WILL DIMINISH AS SURFACE BOUNDARY CLEARS COASTAL AREAS...LIKELY BY THE 15-18Z TIME FRAME MONDAY. ..KERR.. 01/07/2007  From swody2 at goshenarc.org Sun Jan 7 16:44:41 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 07 Jan 2007 11:44:41 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 071648 SWODY2 SPC AC 071647 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1047 AM CST SUN JAN 07 2007 VALID 081200Z - 091200Z ...NO SVR TSTM AREAS FORECAST... ...SRN MID-ATLANTIC REGION... PLAINS MID-LEVEL TROUGH WILL MOVE QUICKLY EWD AND OFF THE ERN SEABOARD BY MONDAY NIGHT AS THE NEXT SPEED MAX TRANSLATES SEWD ACROSS THE NRN TIER OF THE COUNTRY. FRONT ASSOCD WITH THE LEAD DISTURBANCE SHOULD BE SITUATED FROM NY SWD ACROSS THE ERN SLOPES OF THE APPALACHIAN MOUNTAINS TO THE ERN GULF BASIN AT 12Z MON. BANDS OF CONVECTION/TSTMS WILL LIKELY BE PRESENT ALONG/E OF THE FRONT ACROSS THE SRN MID-ATLANTIC REGION MON MORNING. THIS ACTIVITY WILL MOVE OFF THE COAST BETWEEN 18-21Z. THE STRONGER FORCING FOR ASCENT AND STEEP LAPSE RATES ASSOCD WITH THE UPPER TROUGH WILL MOVE PRIMARILY N OF THE MORE SUBSTANTIAL WARM SECTOR CONFINED TO THE SERN STATES. THUS...PROSPECTS FOR A WELL-ORGANIZED SEVERE MCS ARE UNLIKELY. BUT...ISOLD DAMAGING WIND GUSTS CANNOT BE RULED OUT ALONG NRN PORTIONS OF THE THETA-E AXIS ACROSS ESPECIALLY ERN NC NWD INTO SERN VA AND THE LWR-ERN MD SHORE THROUGH EARLY AFTN. FORECAST SOUNDINGS SUGGEST THAT VERY STRONG WINDS JUST ABOVE THE SFC MAY BE MIXED DOWNWARD IN THE STRONGER SFC-BASED CONVECTIVE CELLS ALONG THE FRONT. CONVECTION WILL LIKELY WEAKEN WITH SWD EXTENT ALONG THE COLD FRONT INTO THE SERN STATES AS PRIMARY FORCING LIFTS NEWD AWAY FROM THE REGION. ..RACY.. 01/07/2007  From swody2 at goshenarc.org Mon Jan 8 05:39:18 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 08 Jan 2007 00:39:18 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 080542 SWODY2 SPC AC 080541 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1141 PM CST SUN JAN 07 2007 VALID 091200Z - 101200Z ...NO SVR TSTM AREAS FORECAST... MODELS INDICATE THAT A LARGE-SCALE POLAR TROUGH WILL REMAIN AMPLIFIED ACROSS THE EASTERN STATES THROUGH LATE TUESDAY...AS A SIGNIFICANT SHORT WAVE IMPULSE CONTINUES INTO/THROUGH ITS BASE... ACROSS THE SOUTHERN MID ATLANTIC COAST STATES. THEREAFTER...THE SHORT WAVE IS PROGGED TO LIFT INTO THE WESTERN ATLANTIC...WITH A BIT MORE ZONAL FLOW DEVELOPING EAST OF THE MISSISSIPPI VALLEY...WELL AHEAD OF THE NEXT POLAR TROUGH DIGGING INTO THE NORTHWESTERN STATES. A WEAK TROUGH IN THE SUBTROPICAL STREAM IS PROGGED TO LIFT TOWARD BAJA IN ADVANCE OF THE LATTER FEATURE. AND...MID/HIGH LEVEL MOISTURE WILL BEGIN TO ADVECT ACROSS THE NORTHERN MEXICAN PLATEAU TOWARD THE SOUTH CENTRAL STATES. HOWEVER...THE CENTER OF A SURFACE RIDGE...SHIFTING SOUTHEASTWARD INTO THE WESTERN GULF STATES DURING THE DAY TUESDAY...WILL NOT BEGIN TO RETREAT UNTIL VERY LATE IN THE FORECAST PERIOD. UNTIL THIS OCCURS...MODIFICATION OF THE BOUNDARY LAYER OVER THE WESTERN GULF OF MEXICO...AND A RETURN FLOW INLAND...WILL BE INHIBITED. A DRY STABLE ENVIRONMENT WILL RESULT IN A NEGLIGIBLE RISK OF THUNDERSTORMS DURING THIS PERIOD ACROSS MUCH OF THE NATION...WITH PARTS OF THE PACIFIC NORTHWEST A POSSIBLE EXCEPTION. ...PACIFIC NORTHWEST... MODELS SUGGEST THAT THE COLD CORE OF THE UPPER TROUGH /WITH 700-500 MB TEMPERATURES OF -20 TO -40 C/ WILL MIGRATE INLAND ACROSS THE PACIFIC NORTHWEST COAST TUESDAY NIGHT. AND...LOW-LEVEL MOISTENING ASSOCIATED WITH ONSHORE FLOW TO THE WEST OF THE CASCADES MAY CONTRIBUTE TO SUFFICIENT CAPE THROUGH THE LOWERING MIXED PHASE LAYER...WITH FAVORABLY COLD EQUILIBRIUM LEVELS...TO SUPPORT A RISK FOR SCATTERED THUNDERSTORM ACTIVITY. ..KERR.. 01/08/2007  From swody2 at goshenarc.org Mon Jan 8 16:56:34 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 08 Jan 2007 11:56:34 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 081659 SWODY2 SPC AC 081657 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1057 AM CST MON JAN 08 2007 VALID 091200Z - 101200Z ...NO SVR TSTM AREAS FORECAST... ...PACIFIC NW... STRONG POST FRONTAL COLD ADVECTION WILL DRAMATICALLY STEEPEN LAPSE RATE ENVIRONMENT ACROSS THE PACIFIC NW DURING THE LATTER HALF OF THE PERIOD. FORECAST SOUNDINGS FOR COASTAL WA/NW ORE SUGGEST BOUNDARY LAYER CONVECTION WILL DEVELOP WITHIN ONSHORE FLOW REGIME AROUND 00Z...WITH ACTIVITY EXPECTED TO DEEPEN SUFFICIENTLY FOR LIGHTNING WITHIN LOW-TOPPED UPDRAFTS...ALTHOUGH EL LEVELS WILL GRADUALLY RISE TO NEAR 500MB BY THE END OF THE PERIOD. COLD PROFILES SUGGEST SMALL HAIL MAY ACCOMPANY THE STRONGER UPDRAFTS. ...LAKE ONTARIO... LAPSE RATES WILL STEEPEN...ESPECIALLY AFTER 00Z...ACROSS LAKE ONTARIO WITHIN NW FLOW BENEATH UPPER TROUGH TUESDAY. ALTHOUGH LAKE EFFECT SHOWERS SHOULD EVOLVE...OVER/DOWNWIND OF THE LAKE...AS THERMODYNAMIC PROFILES BECOME MORE UNSTABLE...IT APPEARS LIGHTNING WILL BE EXTREMELY ISOLATED AND WILL NOT OUTLOOK THUNDERSTORMS ACROSS THIS REGION. ..DARROW.. 01/08/2007  From swody2 at goshenarc.org Tue Jan 9 05:02:54 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Tue, 09 Jan 2007 00:02:54 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 090506 SWODY2 SPC AC 090505 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1105 PM CST MON JAN 08 2007 VALID 101200Z - 111200Z ...NO SVR TSTM AREAS FORECAST... MODELS INDICATE THAT THE POLAR TROUGH PROGGED TO DIG INTO THE NORTHWESTERN U.S. BY 12Z WEDNESDAY WILL BE ACCOMPANIED BY A SIGNIFICANT COLD INTRUSION. THIS WILL OCCUR TO THE LEE OF THE NORTHERN ROCKIES...AS ONE VIGOROUS EMBEDDED IMPULSE PROGRESSES EASTWARD THROUGH THE CENTRAL CANADIAN/U.S. BORDER AREA BY 12Z THURSDAY. THE COLD FRONT WILL ALSO SURGE THROUGH MUCH OF THE NORTHERN AND CENTRAL GREAT BASIN...AS ANOTHER SIGNIFICANT IMPULSE DIGS SOUTHWARD ACROSS THE PACIFIC COAST STATES. IN ADVANCE OF THE LATTER FEATURE...AN INCREASING SHEARED TROUGH IN THE SUBTROPICAL STREAM IS PROGGED TO BEGIN LIFTING ACROSS BAJA AND THE NORTHERN MEXICAN PLATEAU...INTO PARTS OF THE SOUTHERN ROCKIES AND SOUTH CENTRAL STATES. THIS LIKELY WILL BE ACCOMPANIED BY AN INFLUX OF MOISTURE IN AN UPPER PLUME OFF THE LOWER LATITUDE PACIFIC...WHICH WILL BEGIN TO GRADUALLY SATURATE THE ENVIRONMENT IN PROGRESSIVELY LOWER LEVELS. WHILE A SOUTHERLY LOW-LEVEL FLOW WILL PROBABLY DEVELOP OFF THE WESTERN GULF OF MEXICO INTO THE SOUTHERN PLAINS TOWARD THE END OF THE PERIOD...THE GULF BOUNDARY LAYER IS EXPECTED TO BE JUST BEGINNING TO MODIFY...IN THE WAKE OF A RETREATING SURFACE RIDGE. ...EAST OF THE ROCKIES... NEAR MOIST ADIABATIC LAPSE RATES WITHIN ELEVATED PACIFIC MOIST PLUME AND LIMITED LOW-LEVEL MOISTURE RETURN FROM THE GULF OF MEXICO ARE EXPECTED TO INHIBIT DESTABILIZATION...RESULTING IN NEGLIGIBLE RISK FOR THUNDERSTORMS WEDNESDAY/WEDNESDAY NIGHT. ...WEST OF ROCKIES... SURFACE COLD FRONT SURGING AHEAD OF MID-LEVEL COLD CORE WILL INHIBIT DESTABILIZATION ACROSS MUCH OF THE INTERMOUNTAIN WEST. HOWEVER...POST-FRONTAL LOW-LEVEL TEMPERATURES WEST OF THE CASCADES ...BENEATH UPPER COLD CORE...MAY REMAIN WARM ENOUGH TO SUPPORT VERY WEAK CAPE. THIS MAY EXTEND THROUGH A RATHER SHALLOW LAYER...BUT MIXED PHASE LAYER WILL BE LOW...AND EQUILIBRIUM LEVEL TEMPERATURES SHOULD BE FAVORABLY COLD FOR ISOLATED/WIDELY SCATTERED THUNDERSTORM ACTIVITY. ..KERR.. 01/09/2007  From swody2 at goshenarc.org Fri Jan 12 06:24:21 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 12 Jan 2007 01:24:21 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 120614 SWODY2 SPC AC 120613 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1213 AM CST FRI JAN 12 2007 VALID 131200Z - 141200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... POSITIVELY TILTED UPPER TROUGH WILL CONTINUE TO DROP SLOWLY SWD AND INTO THE SWRN U.S. SATURDAY. DOWNSTREAM FROM THIS FEATURE...A BROAD LOW AMPLITUDE UPPER RIDGE WILL EXIST FROM THE MS VALLEY EWD THROUGH PARTS OF THE OH VALLEY AND SERN STATES. AT THE SURFACE A COLD ARCTIC FRONT WILL CONTINUE SWD. BY 12Z SATURDAY THIS BOUNDARY SHOULD EXTEND FROM THE NERN U.S. SWWD INTO THE LOWER MS VALLEY THROUGH CNTRL AND WRN TX. THIS SHALLOW WEDGE OF COLD AIR SHOULD CONTINUE SLOWLY SWD THROUGH TX DURING THE DAY. ...SWRN THROUGH S CNTRL AND ERN TX... PARTIALLY MODIFIED GULF AIR WITH BOUNDARY LAYER DEWPOINTS MAINLY IN THE LOW TO MID 60S WILL HAVE ADVECTED NWD INTO THE PRE-FRONTAL WARM SECTOR OF SRN AND S CNTRL TX INTO THE LOWER MS VALLEY. SOMEWHAT STRONGER MID LEVEL LAPSE RATES AROUND 6.5 C/KM INITIALLY OVER SWRN TX MAY ADVECT INTO PARTS OF S CNTRL TX ABOVE THE RETURNING LOW LEVEL MOISTURE. THIS ALONG WITH POTENTIAL FOR PRE-FRONTAL SURFACE HEATING SHOULD CONTRIBUTE TO SOME DESTABILIZATION DURING THE DAY WITH MUCAPE FROM 400 TO 800 J/KG NEAR AND JUST S OF THE FRONT. MODELS SUGGEST CONVECTION MAY ALREADY BE IN PROGRESS FROM PARTS OF NERN TX...ERN OK INTO THE LOWER MS VALLEY. HOWEVER...THIS ACTIVITY WILL BE ELEVATED IN POST FRONTAL ZONE WHERE CAPE WILL BE LIMITED. OTHER STORMS MAY DEVELOP DURING THE AFTERNOON IN VICINITY OF THE FRONT AS THE ATMOSPHERE DESTABILIZES. HOWEVER...ORIENTATION OF THE MEAN DEEP LAYER FLOW WITH RESECT THE FRONT SUGGEST STORMS WILL LIFT NEWD OVER THE COOL FRONTAL SURFACE AND BECOME ELEVATED...ESPECIALLY OVER S CNTRL THROUGH SWRN TX. STORMS MAY INCREASE OVERNIGHT NEAR AND N OF THE FRONT AS THE SLY LOW LEVEL JET AND FORCING FOR ASCENT STRENGTHENS DOWNSTREAM FROM ADVANCING UPPER TROUGH. VERTICAL SHEAR FOR STORMS DEVELOPING NEAR THE FRONT WILL BE SUFFICIENT FOR SUPERCELLS. HOWEVER...TENDENCY WILL REMAIN FOR STORMS TO LIFT NEWD AND BECOME ELEVATED. INSTABILITY AND MID LEVEL LAPSE RATES MAY BECOME SUFFICIENT FOR A THREAT OF MARGINALLY SEVERE HAIL. FARTHER EAST ACROSS PARTS OF ERN TX...A MORE NE ORIENTATION OF THE FRONT SUGGESTS ANY STORMS DEVELOPING ALONG OR S OF THIS PART OF THE BOUNDARY MAY HAVE A BETTER CHANCE OF REMAINING SURFACE BASED. HOWEVER...MODEST LAPSE RATES/INSTABILITY AND WEAKER FORCING FOR DEEP LAYER ASCENT IN THIS REGION SHOULD SERVE AS LIMITING FACTORS. ..DIAL.. 01/12/2007  From swody2 at goshenarc.org Fri Jan 12 17:17:32 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 12 Jan 2007 12:17:32 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 121720 SWODY2 SPC AC 121719 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1119 AM CST FRI JAN 12 2007 VALID 131200Z - 141200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... WRN U.S. MID-LEVEL TROUGH IS FORECAST TO BEGIN MAKING MORE SUBSTANTIAL EWD PROGRESS...PARTICULARLY THROUGH THE LATTER HALF OF THE PERIOD. MEANWHILE...SURFACE COLD FRONT WILL CONTINUE MOVING SWD ACROSS TX...WHILE REMAINING QUASI-STATIONARY FROM AR ENEWD ACROSS THE OH VALLEY REGION. THOUGH LACK OF INSTABILITY WILL PRECLUDE THUNDERSTORMS ACROSS MUCH OF THE COUNTRY...LOW-LEVEL WARM/MOIST ADVECTION AHEAD OF APPROACHING UPPER TROUGH WILL CONTRIBUTE TO WIDESPREAD SHOWERS AND THUNDERSTORMS OVER THE S CENTRAL CONUS. ...MIDDLE RIO GRANDE VALLEY ENEWD INTO ERN TX... SHOWERS AND THUNDERSTORMS SHOULD BE ONGOING AT THE START OF THE PERIOD ACROSS THE SRN PLAINS/AR...NEAR AND N OF SWD-MOVING COLD FRONT. WHILE WIDESPREAD PRECIPITATION SHOULD LIMIT POTENTIAL FOR DESTABILIZATION...MODELS DO SUGGEST SLIGHTLY STEEPER LAPSE RATES SHOULD ADVECT NEWD WHICH MAY CONTRIBUTE TO AOB 500 J/KG MOST-UNSTABLE CAPE BY THE AFTERNOON. DEEP-LAYER WIND FIELD -- FEATURING 50 KT SWLY FLOW AT MID-LEVELS -- WILL YIELD SHEAR SUFFICIENT FOR SUPERCELLS. HOWEVER...WEAKLY-CAPPED AIRMASS S OF FRONT -- ALONG WITH TENDENCY FOR ANY SURFACE-BASED STORMS WHICH CAN DEVELOP TO MOVE NNEWD ACROSS THE FRONT -- SHOULD LIMIT MAIN SEVERE THREAT TO HAIL WITH ELEVATED STORMS N OF BOUNDARY. ALONG WITH THE POTENTIAL FOR AN ISOLATED WIND GUST OR BRIEF TORNADO WITH A SURFACE-BASED STORM OR TWO NEAR OR JUST N OF THE FRONT...POTENTIAL FOR A FEW MARGINALLY-SEVERE HAILSTONES SUPPORTS THE CONTINUANCE OF 5% PROBABILITY SEVERE AREA THIS PERIOD. ..GOSS.. 01/12/2007  From swody2 at goshenarc.org Sat Jan 13 11:04:34 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 13 Jan 2007 06:04:34 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 131107 SWODY2 SPC AC 131106 DAY 2 CONVECTIVE OUTLOOK RESENT 1 NWS STORM PREDICTION CENTER NORMAN OK 0506 AM CST SAT JAN 13 2007 VALID 141200Z - 151200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... POSITIVELY TILTED UPPER TROUGH NOW FROM THE NRN ROCKIES TO THE GREAT BASIN REGION WILL CONTINUE SLOWLY EWD THROUGH SUNDAY. A SHORTWAVE TROUGH WILL ROTATE THROUGH BASE OF THE UPPER TROUGH AND EJECT NEWD THROUGH THE CNTRL PLAINS AND MID-UPPER MS VALLEY THIS PERIOD. AS THIS OCCURS A WEAK WAVE WILL DEVELOP ALONG THE FRONT OVER THE LOWER MS VALLEY SUNDAY AFTERNOON AND LIFT NEWD INTO THE OH VALLEY SUNDAY NIGHT. THIS WILL PROVIDE IMPETUS FOR THE ARCTIC FRONT TO CONTINUE SEWD THROUGH MUCH OF THE REMAINDER OF S TX THROUGH THE LOWER MS VALLEY SUNDAY NIGHT. ...S TX THROUGH THE LOWER MS VALLEY... MOIST BOUNDARY LAYER AIR WITH DEWPOINTS IN THE MID 60S WILL PERSIST IN THE PRE-FRONTAL WARM SECTOR ACROSS MUCH OF S AND ERN TX INTO THE LOWER MS VALLEY SUNDAY. HOWEVER...WEAK MID LEVEL LAPSE RATES AND LIMITED SURFACE HEATING SUGGEST INSTABILITY WILL REMAIN VERY MARGINAL WITH MUCAPE BELOW 500 J/KG. LOW LEVEL JET INITIALLY OVER SRN AND ERN TX EARLY SUNDAY WILL SHIFT NEWD INTO THE LOWER MS VALLEY LATER IN THE DAY AND INTO THE TN VALLEY OVERNIGHT ALONG TRACK OF DEVELOPING SURFACE LOW. HOWEVER...STRONGER FORCING ASSOCIATED WITH EJECTING SHORTWAVE TROUGH WILL REMAIN ON COLD...STABLE SIDE OF FRONT...SUGGESTING CYCLOGENESIS WILL BE WEAK. POST FRONTAL ELEVATED CONVECTION WILL BE ONGOING EARLY SUNDAY FROM S CNTRL TX NEWD INTO THE LOWER MS VALLEY. ACTIVITY WILL SHIFT SLOWLY EWD DURING THE DAY. MOST STORMS SHOULD REMAIN CONFINED TO NEAR OR BEHIND ARCTIC FRONT DUE TO UNFAVORABLE THERMODYNAMIC PROFILES AND WEAK FORCING FOR ASCENT IN WARM SECTOR. DESPITE FAVORABLE HODOGRAPHS FOR SUPERCELLS AND ISOLATED TORNADOES WITHIN PRE-FRONTAL WARM SECTOR ALONG TRACK OF LOW LEVEL JET...SEVERE THREAT THIS PERIOD IS EXPECTED TO REMAIN LIMITED DUE TO AN ANTICIPATED VERY MARGINAL THERMODYNAMIC ENVIRONMENT. IF IT BEGINS TO APPEAR MORE SURFACE BASED INSTABILITY WILL DEVELOP THAN CURRENTLY EXPECTED...AN UPGRADE TO SLIGHT RISK MAY BE NEEDED IN LATER OUTLOOKS. ..DIAL.. 01/13/2007  From swody2 at goshenarc.org Sun Jan 14 05:43:54 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 14 Jan 2007 00:43:54 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 140547 SWODY2 SPC AC 140546 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1146 PM CST SAT JAN 13 2007 VALID 151200Z - 161200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... POSITIVELY TILTED UPPER TROUGH WILL EXTEND FROM THE UPPER MS VALLEY SWWD THROUGH THE SWRN STATES MONDAY. A STRONG SHORTWAVE TROUGH NOW ROTATING THROUGH BASE OF UPPER TROUGH OVER AZ WILL CONTINUE NEWD THROUGH THE GREAT LAKES AND INTO THE NERN U.S. THIS PERIOD. ATTENDANT SURFACE LOW INITIALLY OVER THE OH VALLEY WILL MOVE NE AND OFFSHORE MONDAY NIGHT. TRAILING ARCTIC FRONT WILL CONTINUE TO SURGE SWD THROUGH THE REMAINDER OF THE SRN PLAINS...LOWER MS VALLEY AND MUCH OF THE SERN STATES. ...S THROUGH S CNTRL TX... ISENTROPIC LIFT IN WAKE OF SWD ADVANCING ARCTIC FRONT AND SHORTWAVE TROUGHS EMBEDDED WITHIN SUBTROPICAL MOIST PLUME WILL CONTRIBUTE TO THE DEVELOPMENT OF PRECIPITATION IN POST FRONTAL ZONE OVER PARTS OF TX INTO THE LOWER MS VALLEY. FORECAST SOUNDING SHOW SOME CONVECTIVE INSTABILITY IN THE 700 MB TO 500 MB MIXED PHASE LAYERS OVER PARTS OF S THROUGH S CNTRL TX. HOWEVER...MID LEVEL LAPSE RATES WILL BE WEAK RESULTING IN LIMITED INSTABILITY WITH MUCAPE AOB 200 J/KG. LIGHTNING STRIKES COULD ACCOMPANY SOME OF THIS ELEVATED...SHALLOW CONVECTION. HOWEVER...WEAK INSTABILITY AND POOR LAPSE RATES SUGGEST ANY LIGHTING ACTIVITY SHOULD REMAIN ISOLATED. ..DIAL.. 01/14/2007  From swody2 at goshenarc.org Sun Jan 14 17:00:04 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 14 Jan 2007 12:00:04 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 141703 SWODY2 SPC AC 141701 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1101 AM CST SUN JAN 14 2007 VALID 151200Z - 161200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... LARGE UPPER TROUGH OVER THE WRN AND CENTRAL CONUS WILL TAKE ON AN INCREASINGLY-POSITIVE TILT...AS NRN PORTION OF THE TROUGH SHIFTS EWD ACROSS THE NRN HALF OF THE CONUS WHILE SRN PORTION LINGERS OVER THE SWRN CONUS. AT THE SURFACE...LOW INITIALLY OVER THE MID/UPPER OH VALLEY REGION -- ASSOCIATED WITH NRN PORTION OF THE UPPER TROUGH -- WILL MOVE NEWD ACROSS NEW ENGLAND AND LIKELY INTO THE ATLANTIC BY THE END OF THE PERIOD. TRAILING COLD FRONT WILL SURGE SWD OUT OF THE S CENTRAL U.S. INTO MEXICO/THE GULF OF MEXICO EARLY...WHILE ALSO MOVING SEWD ACROSS THE MID-ATLANTIC REGION/THE SOUTHEAST THROUGH 16/12Z. ...PORTIONS OF CENTRAL/ERN/S TX... COLD FRONT SHOULD EXTEND FROM SRN LA SWWD ACROSS THE WRN GULF INTO DEEP S TX AT THE START OF THE PERIOD...AND SHOULD CROSS THE RIO GRANDE INTO NERN MEXICO SHORTLY AFTER THE START OF THE PERIOD. ABOVE PRONOUNCED NLY SURFACE WINDS...LOW-LEVEL FLOW WILL REMAIN FROM A SLY DIRECTION -- AT LEAST DURING THE FIRST HALF OF THE PERIOD. THE RESULTING ISENTROPIC LIFT/WARM ADVECTION OVER THE SHALLOW SURFACE COLD LAYER WILL RESULT IN PRECIPITATION...AND POSSIBLY A FEW EMBEDDED/ELEVATED THUNDERSTORMS. MINIMAL INSTABILITY WILL PRECLUDE ANY SEVERE THREAT...AND THUNDERSTORM POTENTIAL SHOULD DECREASE WITH TIME. ...ELSEWHERE... POTENTIAL FOR A LIGHTNING STRIKE OR TWO MAY SHIFT EWD FROM THE MID OH VALLEY REGION ACROSS THE CENTRAL APPALACHIANS AND MID-ATLANTIC REGION THROUGH THE FIRST HALF OF THE PERIOD AHEAD OF COLD FRONT. HOWEVER...INSTABILITY APPEARS INSUFFICIENT TO WARRANT THE INCLUSION OF A 10% PROBABILITY THUNDER LINE ATTM. ..GOSS.. 01/14/2007  From swody2 at goshenarc.org Mon Jan 15 05:32:27 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 15 Jan 2007 00:32:27 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 150535 SWODY2 SPC AC 150534 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1134 PM CST SUN JAN 14 2007 VALID 161200Z - 171200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... NRN BRANCH OF POSITIVELY TILTED UPPER TROUGH IS FORECAST TO MOVE EAST THROUGH THE OH VALLEY AND THE NERN STATES TUESDAY LEAVING SRN BRANCH AS A CUTOFF UPPER LOW NEAR FOUR CORNERS REGION. COLD ARCTIC SURFACE HIGH PRESSURE WILL CONTINUE TO SPREAD SEWD OVER MUCH OF THE NATION. SWLY FLOW ALOFT DOWNSTREAM FROM UPPER TROUGH OVER THE SWRN STATES WILL MAINTAIN ISENTROPIC ASCENT AND AREAS OF PRECIPITATION OVER PARTS OF S TX. HOWEVER...GIVEN POOR LAPSE RATES...ANY ELEVATED INSTABILITY WILL BE VERY MARGINAL AND ANY CHANCE FOR LIGHTNING WITH THIS ACTIVITY SHOULD REMAIN LESS THAN 10%. ..DIAL.. 01/15/2007  From swody2 at goshenarc.org Tue Jan 16 04:59:34 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 15 Jan 2007 23:59:34 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 160502 SWODY2 SPC AC 160500 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1100 PM CST MON JAN 15 2007 VALID 171200Z - 181200Z ...NO TSTM AREAS FORECAST... ...DISCUSSION... COLD ARCTIC HIGH PRESSURE WITH OFFSHORE FLOW OVER THE GULF WILL PREVAIL OVER MUCH OF THE NATION THIS PERIOD. A SHORTWAVE TROUGH CURRENTLY OVER THE NERN PACIFIC WILL DROP SWD THROUGH CA WEDNESDAY. STEEP LAPSE RATES AND LIFT ACCOMPANYING THIS FEATURE MAY CONTRIBUTE TO A FEW SHOWERS ACROSS PARTS OF THE CNTRL OR SRN CA COASTAL AREAS. HOWEVER...AT THIS TIME COVERAGE OF ANY LIGHTNING ACTIVITY IS EXPECTED TO REMAIN LESS THAN 10%. ..DIAL.. 01/16/2007  From swody2 at goshenarc.org Fri Jan 19 06:31:50 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 19 Jan 2007 01:31:50 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 190634 SWODY2 SPC AC 190632 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1232 AM CST FRI JAN 19 2007 VALID 201200Z - 211200Z ...NO SVR TSTM AREAS FORECAST... ...ERN TX AND WRN LA... A SRN BRANCH UPPER LOW WILL EJECT ENEWD...REACHING THE SRN ROCKIES BY EARLY SATURDAY AND THE PLAINS SATURDAY NIGHT. PRIMARY SFC LOW WILL LIKELY REMAIN OVER THE HIGHER PLAINS...BUT A WEAK LOW WILL LIKELY FORM IN SERN TX AND SLOWLY LIFT NEWD SATURDAY NIGHT. SLY LLJ WILL STRENGTHEN SATURDAY ACROSS CNTRL TX AND TRANSLATE EWD SATURDAY NIGHT CONTRIBUTING TO INCREASING MOISTURE TRANSPORT. RECENT INTRUSION OF CP AIR MASS INTO THE WRN GULF BASIN WILL LIMIT MAGNITUDE OF THE MOISTURE RETURN AND LAPSE RATES ARE EXPECTED TO REMAIN WEAK. THUS...SEVERE WEATHER IS NOT A CONCERN. BUT...AS SRN PERIPHERY OF LARGER SCALE HEIGHT FALLS SPREAD ACROSS THE REGION...ISOLD TSTMS WILL BE POSSIBLE...PRIMARILY ACROSS ERN TX AND WRN LA. ..RACY.. 01/19/2007  From swody2 at goshenarc.org Fri Jan 19 17:02:21 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Fri, 19 Jan 2007 12:02:21 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 191704 SWODY2 SPC AC 191703 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1103 AM CST FRI JAN 19 2007 VALID 201200Z - 211200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS AND FORECAST... MID AND UPPER LEVEL LOW CURRENTLY MOVING ACROSS NRN BAJA CA IS FORECAST TO EJECT NEWD AS AN OPEN WAVE THROUGH THE SRN HIGH PLAINS INTO LOWER MO VALLEY IN RESPONSE TO DIGGING...UPSTREAM JET OVER THE PACIFIC NW INTO GREAT BASIN. IN THE LOW-LEVELS...SURFACE HIGH NOW BUILDING SEWD THROUGH THE SRN LOW PLAINS INTO LOWER MS VALLEY WILL BE SLOW TO ERODE WITH SOME WEAK BOUNDARY AND FRONTAL WAVE BECOMING BETTER DEFINED WITH TIME OVER E TX INTO THE LOWER MS VALLEY. THE EJECTING MID-LEVEL TROUGH WILL INDUCE LLJ DEVELOPMENT OVER E TX INTO THE LOWER MS VALLEY AND MID SOUTH...WITH A RESULTANT INCREASE IN MOIST/THERMAL ADVECTION ABOVE NEAR SURFACE INVERSION. LAPSE RATES WILL BE POOR IN THE MID-LEVELS WITH TEMPERATURE PROFILES REMAINING GENERALLY TOO WARM FOR CHARGE SEPARATION/LIGHTNING DEVELOPMENT. STILL...SOME POTENTIAL WILL EXIST FOR EMBEDDED POCKETS OF WEAK CONVECTIVE INSTABILITY WITHIN WARM CONVEYOR PRECIPITATION BAND WHICH COULD SUPPORT ISOLATED TSTM DEVELOPMENT. ..MEAD.. 01/19/2007  From swody2 at goshenarc.org Sat Jan 20 06:30:04 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 20 Jan 2007 01:30:04 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 200632 SWODY2 SPC AC 200630 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1230 AM CST SAT JAN 20 2007 VALID 211200Z - 221200Z ...NO SVR TSTM AREAS FORECAST... ...LWR MS VLY... UPPER LOW CURRENTLY OVER SRN AZ/NRN SONORA WILL EJECT ENEWD ACROSS THE PLAINS LATE TODAY AND INTO THE GREAT LAKES AS AN OPEN WAVE BY LATE SUNDAY. ATTENDANT FRONT WILL MOVE SEWD AND BE SITUATED FROM THE SRN APPALACHIANS TO THE WRN GULF COAST BY 12Z MON. MEANWHILE...A PIECE OF THE DISTURBANCE NOW OFF THE BC/WA COASTS WILL AMPLIFY AND DIG SWD THROUGH THE GRT BASIN ON SUNDAY. TIGHTENING HEIGHT GRADIENT DOWNSTREAM FROM THIS SYSTEM WILL CONTRIBUTE TO ACCELERATED FLOW WITHIN THE SUB-TROPICAL CONVEYOR. THIS JETSTREAM WILL BE IN PLACE FROM THE WRN GULF BASIN INTO THE DEEP S ATOP THE AFOREMENTIONED FRONT. THOUGH LAPSE RATES ARE GENERALLY EXPECTED TO BE MOIST ADIABATIC OR LESS...THE INCREASING FLOW ALOFT MAY PROVIDE SUFFICIENT FORCING FOR SOME PARCELS TO REACH INTO THE ICING LAYER FOR CHARGE SEPARATION ACROSS THE LWR MS VLY SUNDAY AFTN/NIGHT. NO ORGANIZED SVR TSTMS ARE ANTICIPATED OWING TO THE POOR LAPSE RATES AND MARGINAL GULF MSTR RETURN. ..RACY.. 01/20/2007  From swody2 at goshenarc.org Sat Jan 20 16:58:06 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sat, 20 Jan 2007 11:58:06 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 201703 SWODY2 SPC AC 201701 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1101 AM CST SAT JAN 20 2007 VALID 211200Z - 221200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... MID AND UPPER LEVEL LOW CURRENTLY OVER NM IS FORECAST TO EVOLVE INTO AN OPEN WAVE AND DEAMPLIFY AS IT LIFTS NEWD THROUGH THE CNTRL/SRN PLAINS TODAY/TONIGHT AND INTO THE OH VALLEY SUNDAY. AS THIS OCCURS...DIGGING MID AND HIGH LEVEL JET STREAKS WILL CONTRIBUTE TO THE FORMATION OF UPSTREAM CLOSED LOW OVER THE SWRN DESERTS. IN THE LOW LEVELS...WEAKENING SURFACE LOW ATTENDANT TO DEAMPLIFYING WAVE WILL DEVELOP NEWD FROM CNTRL KS OR NWRN OK INTO THE OH VALLEY WITH TRAILING COLD FRONT PUSHING SWD THROUGH THE SRN PLAINS. MEANWHILE...SECONDARY LOW PRESSURE NOW OFF THE LOWER TX COAST WILL DEVELOP NEWD THROUGH THE LOWER MS VALLEY INTO SRN APPALACHIANS WITH TRAILING WEAK FRONT PUSHING EWD/SEWD THROUGH THE WRN/CNTRL GULF COAST. ...GULF COAST... SWLY LLJ /INDUCED BY WEAKENING WAVE LIFTING THROUGH THE OH VALLEY/ WILL SLOWLY MIGRATE EWD ACROSS THE REGION...SUPPORTING AN INCREASINGLY MOIST AIR MASS AHEAD OF LOWER LATITUDE SURFACE LOW AND ATTENDANT FRONT. THIS MOISTENING COUPLED WITH PERSISTENT ISENTROPIC ASCENT IS EXPECTED TO MAINTAIN A BAND OF SHOWERS WITH A FEW EMBEDDED TSTMS WITHIN PRE-FRONTAL AIR MASS. WHILE DEWPOINTS WILL INCREASE INTO THE LOW TO PERHAPS MID 60S ALONG AND S OF THE I-10 CORRIDOR...LAPSE RATES AND RESULTANT INSTABILITY WILL REMAIN QUITE WEAK. THEREFORE...DESPITE THE MODERATELY STRONG WIND FIELDS...NO SEVERE STORMS ARE FORECAST. ..MEAD.. 01/20/2007  From swody2 at goshenarc.org Sun Jan 21 06:35:23 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 21 Jan 2007 01:35:23 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 210640 SWODY2 SPC AC 210638 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1238 AM CST SUN JAN 21 2007 VALID 221200Z - 231200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... THE UPPER LEVEL DISTURBANCE OVER THE CNTRL PLAINS LATE SATURDAY EVE WILL WEAKEN AND SHEAR EWD THROUGH THE MIDWEST AND MID-ATLANTIC SUNDAY AND OUT INTO THE WRN ATLANTIC BASIN BY EARLY MONDAY. THE ATTENDANT SFC FRONT WILL SETTLE INTO THE SERN STATES AND NRN GULF COAST BY 12Z MONDAY AS CYCLOGENESIS OCCURS WELL EAST OF DELMARVA. UPPER JET ENERGY DIVING SEWD ACROSS BC WILL CONTRIBUTE TO AMPLIFICATION OF THE DOWNSTREAM ROCKIES TROUGH. PARTS OF THIS TROUGH WILL CUT-OFF FROM THE FLOW AND SETTLE SWD INTO NRN MEXICO ON MONDAY WHILE THE NRN STREAM PORTION DIGS SEWD INTO THE ERN PARTS OF THE COUNTRY. ...SRN GA/NRN FL,,, SFC LOW EVOLUTION ACROSS THE WRN ATLANTIC BASIN WILL CONTRIBUTE TO A DECIDEDLY WLY COMPONENT TO THE LOW-LEVEL FLOW REGIME ALONG/AHEAD OF THE COLD FRONT MONDAY AFTN/EVE. THIS WILL TEND TO LESSEN THE OVERALL MASS CONVERGENCE OVER THE SERN STATES VCNTY THE FRONT WITH TIME. MID-TROPOSPHERE WILL LIKELY REMAIN WARM BENEATH THE FLATTENING RIDGE AXIS...RESULTING IN THERMODYNAMIC PROFILES LESS CONDUCIVE FOR DEEP MOIST CONVECTION ACROSS CNTRL/SRN FL. FARTHER N...GLANCING INFLUENCE OF LARGER SCALE HEIGHT FALLS/ ASCENT...PRESENCE OF THE FRONT AND MODEST INCREASE IN BOUNDARY LAYER DEW POINTS MAY YIELD A COLUMN SUPPORTIVE FOR PARCELS TO REACH INTO THE ICING LAYER FOR CHARGE SEPARATION. HIGHEST PROBABILITY WILL BE THROUGH MID-AFTN AND MAINLY ACROSS EXTREME NRN/SRN PARTS OF FL/GA RESPECTIVELY. ...SERN AZ/SRN NM... ISOLD TSTMS MAY ACCOMPANY THE STEEPER MID-LEVEL LAPSE RATES ASSOCD WITH THE DIGGING CUT-OFF LOW EXPECTED TO MOVE INTO NRN MEXICO. STRONGER ASCENT SHOULD SHIFT S OF THE INTERNATIONAL BORDER VERY EARLY MONDAY. SLIGHTLY MORE FAVORABLE OROGRAPHICS/MOISTURE SHOULD RESIDE ACROSS NRN SONORA/CHIHUAHUA. AS A RESULT...TSTM PROBABILITIES SHOULD REMAIN LESS THAN 10 PERCENT ACROSS SERN AZ/SRN NM. ..RACY.. 01/21/2007  From swody2 at goshenarc.org Sun Jan 21 16:23:32 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 21 Jan 2007 11:23:32 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 211628 SWODY2 SPC AC 211627 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1027 AM CST SUN JAN 21 2007 VALID 221200Z - 231200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... EWD DEVELOPMENT OF POLAR BRANCH LONG WAVE TROUGH WILL OCCUR ACROSS THE NERN STATES INTO THE WRN ATLANTIC WHILE LOWER LATITUDE MID AND UPPER LEVEL LOW SLOWLY DRIFTS EWD ACROSS NRN MEXICO. IN THE LOW-LEVELS...SURFACE LOW INITIALLY OFF THE NC COAST MONDAY MORNING WILL DEVELOP NEWD INTO THE ATLANTIC WITH TRAILING COLD FRONT PUSHING SEWD THROUGH PORTIONS OF SC/GA INTO THE FL PENINSULA. ...SERN GA INTO THE NRN FL PENINSULA... DESPITE POOR LAPSE RATES...MOIST BOUNDARY LAYER CONDITIONS /DEWPOINTS IN THE MID 60S/ WILL CONTRIBUTE TO AN AXIS OF WEAK INSTABILITY /SBCAPES OF 300-400 J PER KG/ AHEAD OF COLD FRONT BY AFTERNOON. WEAK CAPPING COUPLED WITH FRONTAL CONVERGENCE SHOULD CONTRIBUTE TO AN INCREASE IN CONVECTIVE DEVELOPMENT THROUGH THE DAY. FORECAST SOUNDINGS SUGGEST THAT IN GENERAL MOST UPDRAFTS WILL REMAIN TOO SHALLOW/WARM FOR ICE DEVELOPMENT/CHARGE SEPARATION. HOWEVER...SOME OF THE STRONGER UPDRAFTS SHOULD BE SUPPORTIVE OF LIGHTNING DEVELOPMENT...MAINLY DURING THE AFTERNOON HOURS. ...SERN AZ/SWRN NM... CONSIDERABLY STEEPER LAPSE RATES /7-8 C PER KM/ WILL EXIST MONDAY INVOF UPPER LOW SLOWLY SHIFTING EWD ACROSS NRN MEXICO. WHILE MOST OF THE CONVECTIVE DEVELOPMENT ATTENDANT TO THIS SYSTEM WILL LIKELY REMAIN S OF THE INTERNATIONAL BORDER...A FEW LIGHTNING STRIKES WILL BE POSSIBLE OVER ADJACENT PORTIONS OF SERN AZ/SWRN NM. THIS THREAT APPEARS TOO MINIMAL TOO WARRANT INCLUSION OF AN ADDITIONAL THUNDER AREA. ..MEAD.. 01/21/2007  From swody2 at goshenarc.org Mon Jan 22 06:25:14 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 22 Jan 2007 01:25:14 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 220630 SWODY2 SPC AC 220628 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1228 AM CST MON JAN 22 2007 VALID 231200Z - 241200Z ...NO TSTM AREAS FORECAST... THE POLAR JET IS EXPECTED TO BECOME MORE ACTIVE THROUGH THE WEEK WITH AN INITIAL SHORTWAVE TROUGH MOVING FROM THE CNTRL PORTION OF THE COUNTRY TO OFF THE ERN SEABOARD BY TUE AFTN. THIS DISTURBANCE WILL FLATTEN THE LARGE UPPER RIDGE OVER THE SWRN ATLANTIC...WITH A COLD FRONT LIKELY MOVING THROUGH ALL OF FL AND THE CNTRL GULF OF MEXICO. THE INCREASING NWLY FLOW REGIME ACROSS THESE REGIONS WILL REINFORCE THE FLOW OF CONTINENTAL POLAR AIR WELL S AND PROSPECTS OF DEEP MOIST CONVECTION IS VERY LOW TO NIL OVER THE ERN STATES. MEANWHILE...AS THE WEST COAST RIDGE BUILDS NWD...THE CUT-OFF LOW MOVING INTO NRN MEXICO WILL REMAIN THERE. TSTMS ASSOCIATED WITH THIS SYSTEM SHOULD REMAIN SOUTH IN MEXICO WHERE STEEPER LAPSE RATES BECOME COINCIDENT WITH NWRN EDGE OF THE SUB-TROPICAL JET. ..RACY.. 01/22/2007  From swody2 at goshenarc.org Mon Jan 22 16:42:29 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 22 Jan 2007 11:42:29 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 221647 SWODY2 SPC AC 221645 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1045 AM CST MON JAN 22 2007 VALID 231200Z - 241200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... IN MID-UPPER LEVELS...NRN STREAM PATTERN WILL CONTINUE TO FEATURE SYNOPTIC TROUGH OVER HUDSON BAY AND GREAT LAKES REGIONS...WITH RIDGING OVER PACIFIC NW. PRONOUNCED MID-UPPER CYCLONE -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY AND RAOB ANALYSES OVER AZ/SONORA BORDER -- IS FCST TO BECOME CUT-OFF AND MEANDER ERRATICALLY ACROSS NWRN MEX THROUGH PERIOD. DOWNSTREAM WAA REGIME AND ELEVATED LOW LEVEL FRONTAL ZONE WILL CONTRIBUTE TO INCREASING COVERAGE OF PRECIP FROM N-CENTRAL MEX ACROSS LOWER RIO GRANDE VALLEY TO NWRN GULF. ISOLATED TSTMS MAY OCCUR OVER GULF...HOWEVER FCST SOUNDINGS INDICATE VERY WEAK LAPSE RATES -- PARTICULARLY IN HIGHER/COLDER LAYERS MOST FAVORABLE FOR LIGHTNING -- WILL PRECLUDE GEN TSTM RISK INLAND OVER S TX. ..EDWARDS.. 01/22/2007  From swody2 at goshenarc.org Sun Jan 28 05:52:50 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 28 Jan 2007 00:52:50 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 280557 SWODY2 SPC AC 280556 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1156 PM CST SAT JAN 27 2007 VALID 291200Z - 301200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... STRONG SHORT-WAVE TROUGH MOVING OFF THE MID-ATLANTIC/NEW ENGLAND COAST AT THE START OF THE PERIOD WILL CONTINUE MOVING INTO THE ATLANTIC...WHILE LARGE-SCALE TROUGH REMAINS OVER THE ERN 2/3 OF THE CONUS. MEANWHILE...REX BLOCK WILL PERSIST OVER THE ERN PACIFIC/WRN NOAM. AT THE SURFACE...FRONT S OF FL/THE KEYS WILL CONTINUE MOVING SWD...WHILE HIGH PRESSURE SETTLES SEWD ACROSS THE GULF COAST REGION. WITH MOIST BOUNDARY LAYER SUPPRESSED WELL S OF THE CONUS AND COOL/CONTINENTAL AIRMASS IN PLACE E OF THE ROCKIES...THUNDERSTORMS ARE NOT ANTICIPATED THIS PERIOD. ..GOSS.. 01/28/2007  From swody2 at goshenarc.org Sun Jan 28 17:24:05 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Sun, 28 Jan 2007 12:24:05 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 281728 SWODY2 SPC AC 281727 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1127 AM CST SUN JAN 28 2007 VALID 291200Z - 301200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS/FORECAST... ALTHOUGH UPPER RIDGE OVER THE NERN PACIFIC IS EXPECTED TO STRENGTHEN DURING DAY 2 PERIOD...CLOSED LOW RETROGRADING OFF THE CA COAST TODAY IS EXPECTED TO MOVE SSEWD TOWARD THE SRN CA COAST ON MONDAY RESULTING IN A BREAK DOWN OF THE REX BLOCK. DOWNSTREAM LONG WAVE TROUGH OVER THE ERN TWO-THIRDS OF THE U.S. WILL BE MAINTAINED AS ANOTHER SHORT WAVE TROUGH TRACKS SEWD INTO THE MID MS/OH VALLEYS. COLD FRONT WILL CONTINUE TO MOVE WELL S OF THE CONTINENTAL U.S. AS HIGH PRESSURE SETTLES SWD ACROSS THE GULF COAST AND GULF OF MEXICO. SLY LOW LEVEL FLOW IS EXPECTED TO INCREASE ALONG AND OFF THE S TX COAST IN RESPONSE TO WEAK HEIGHT FALLS AS A PACIFIC SHORT WAVE TROUGH...NOW LOCATED NEAR 20N 132W...TRACKS EWD ACROSS NRN MEXICO TO SRN TX. WRN EXTENT OF COLD FRONT WILL LIKELY REDEVELOP NWD INTO A COASTAL TROUGH OVER THE WRN GULF BASIN BY MONDAY NIGHT. WEAK LOW LEVEL WAA AND MOISTURE RETURN SHOULD SUPPORT SHALLOW CONVECTION MAINLY OFFSHORE LATE IN THE PERIOD...WITH POINT FORECAST SOUNDINGS SUGGESTING CLOUD DEPTHS NOT BECOMING DEEP ENOUGH FOR CHARGE SEPARATION/LIGHTNING PRODUCTION. ELSEWHERE...A FEW LIGHTNING STRIKES MAY DEVELOP OFF THE SRN COAST... ESPECIALLY LATER IN THE FORECAST PERIOD...AS STEEPER LAPSE RATES AND INCREASING ASCENT ACCOMPANYING THE WEST COAST UPPER LOW APPROACH THIS REGION. ..PETERS.. 01/28/2007  From swody2 at goshenarc.org Mon Jan 29 06:34:53 2007 From: swody2 at goshenarc.org (Severe Weather Outlook - Day 2) Date: Mon, 29 Jan 2007 01:34:53 -0500 Subject: [SWODY2] SWODY2 Message-ID: ACUS02 KWNS 290639 SWODY2 SPC AC 290638 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1238 AM CST MON JAN 29 2007 VALID 301200Z - 311200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... CHANGES ARE FORECAST WITH THE UPPER PATTERN THIS PERIOD...AS TWO PRONOUNCED SMALLER-SCALE PERTURBATIONS PROGRESS THROUGH THE ERN U.S. MEAN TROUGH AND THE W COAST REX BLOCK BREAKS DOWN. THE BREAKDOWN OF THE REX BLOCK WILL BE THE ONLY CHANGE OF ANY SIGNIFICANCE WITH RESPECT TO THUNDERSTORM POTENTIAL -- AS STEEPER LAPSE RATES OVER AZ ASSOCIATED WITH THE SEWD APPROACH OF THE UPPER LOW MAY RESULT IN MINIMAL CAPE. THOUGH POSSIBLY SUFFICIENT FOR A FEW ISOLATED LIGHTNING STRIKES...IT APPEARS ATTM THAT OVERALL LIGHTNING COVERAGE SHOULD REMAIN SUFFICIENTLY LOW TO PRECLUDE THE ISSUANCE OF AN OUTLOOK AREA ATTM. ELSEWHERE ACROSS THE CONUS...THUNDERSTORMS ARE NOT ANTICIPATED. ..GOSS.. 01/29/2007