SPC Feb 3, 2012 2000 UTC Day 1 Convective Outlook

SPC 2000Z Day 1 Outlook
DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0135 PM CST FRI FEB 03 2012 VALID 032000Z - 041200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM OK/TX INTO AR AND LA... ...OK...TX...AR...LA... VISIBLE IMAGERY SHOWS AREAS OF HEATING TAKING PLACE ALONG THE WRN EDGE OF THICK STRATUS....AND JUST E OF THE DRYLINE WHICH EXTENDED FROM FDR OK SWWD TO JUST W OF ABI TX AT 19Z. MUCH OF THE ACTIVITY UNTIL THIS POINT HAS BEEN HEAVY RAIN. HOWEVER...THIS AREA OF CLEARING WILL RESULT IN A RIBBON OF RELATIVELY UNSTABLE AIR...AND RADAR TRENDS ALREADY INDICATE STRONG TO SEVERE CELLS FORMING ALONG THE DRYLINE AND NEAR THE DRYLINE/COLD FRONT INTERSECTION. WIND PROFILERS ACROSS THE WARM SECTOR FROM CNTRL OK INTO N TX CONTINUE TO FAVOR SUPERCELLS...AND THE MOIST BOUNDARY LAYER AIR MASS AS WELL AS AMPLE LOW LEVEL SHEAR MAY SUPPORT A FEW TORNADOES. THE MOST FAVORABLE AREA FOR TORNADOES WILL CONTINUE TO BE OVER SRN OK AND NRN TX AHEAD OF THE DEVELOPING CELLS ALONG THE DRYLINE/COLD FRONT. SOME OF THIS ACTIVITY MAY BECOME MORE LINEAR IN PROXIMITY TO THE COLD FRONT...AT WHICH TIME THE TORNADO THREAT WOULD CEASE. CELLS OVER NRN TX MAY HAVE THE BEST TORNADIC POTENTIAL...AND THESE CELLS MAY CROSS THE RED RIVER LATER THIS AFTERNOON. ANOTHER ONGOING AREA OF STORMS IS OVER LA INTO SWRN MS...WHERE CELLS ARE REGENERATING AND MERGING INTO A SMALL CONVECTIVE SYSTEM. THE PRIMARY THREAT WITH THIS ACTIVITY SHOULD BE DAMAGING WIND GUSTS...ALTHOUGH LOCALIZED SHEAR NEAR THE BOUNDARIES COULD RESULT IN A BRIEF AND WEAK TORNADO. LATER THIS EVENING...SHEAR WILL REMAIN FAVORABLE FOR SUPERCELLS OVER ERN OK...NERN TX...AR AND LA. DAMAGING WINDS WILL BE THE MAIN THREAT. A NON-ZERO TORNADO THREAT WILL EXIST WITH CELLS AHEAD OF THE COLD FRONT...UNTIL THEY ARE EITHER UNDERCUT OR MERGE INTO A LINEAR MODE. ..JEWELL.. 02/03/2012 .PREV DISCUSSION... /ISSUED 1019 AM CST FRI FEB 03 2012/ ...SRN PLNS INTO ARKLATEX/LWR MS VLY... MINIMAL CHANGES TO THE PREVIOUS OUTLOOK NEEDED. THERE WILL CONTINUE TO BE A LARGE PART OF THE REGION SUSCEPTIBLE TO STG/SVR STORMS THIS AFTN/TONIGHT...THREATS WILL NOT BE TERRIBLY FOCUSED. 12Z UPR AIR ANALYSIS INDICATES THAT PV-ANOMALY NOW ROTATING THROUGH THE SRN HIGH PLAINS WILL MOVE NE INTO KS. THIS WILL BECOME INCREASINGLY REMOVED FROM SWATH OF RICHER MOISTURE STREAMING FROM SW TX INTO PARTS OF LWR/MID-MS VLY. FORECAST REASONABLY CONFIDENT THAT STG/SVR STORMS WILL CONTINUALLY DEVELOP IN BACKBUILDING NE-SW BANDS ALONG MERGING CDFNT/DRYLINE FEATURES OVER CNTRL/SW OK SWWD INTO NWRN TX THROUGH THIS AFTN. LATEST VSBL SATL IMAGERY SHOWS THAT PRIMARY LLVL HEATING WILL EVOLVE OVER SRN OK AND N TX WHERE MLCAPES COULD REACH 500-1000 J/KG. JUXTAPOSED WITH THIS INSTABILITY...REGION WILL REMAIN WITHIN A BELT OF 50-60 KTS SWLY MID-LVL FLOW ALONG FRINGE OF THE HIGH PLAINS UPR LOW. GIVEN TENDENCY FOR VEERING LLVL FLOW WITH TIME AS THE SFC LOW EJECTS TOWARD NRN OK...WIND PROFILES WILL BE CONDUCIVE FOR SVRL BKN BANDS/CLUSTERS WITH DMGG WIND GUSTS AND HAIL. LOW PROBABILITIES FOR A TORNADO WILL EXIST WITH MORE SUSTAINED STORMS...PRIMARILY WHERE LLVL BUOYANCY WILL BE GREATER OVER SW OK OR WRN N TX. EXISTING EVENING STORMS WILL LIKELY BUILD SLOWLY EWD AND S/SWWD IN AN ELONGATED FASHION FROM ERN OK INTO NRN/ERN/CNTRL TX OVERNIGHT. LOW TO MID LVL LAPSE RATES WILL BE FAIRLY WEAK...AND THE DEEP WIND FIELD ONLY MODERATELY STRONG. BUT SETUP MAY NEVERTHELESS SUPPORT A CONTINUED RISK FOR AT LEAST SPORADIC SVR WEATHER /LOCALLY DMGG WIND AND/OR AN ISOLD TORNADO/ GIVEN QUALITY OF MOISTURE INFLOW AND LIKELY PRESENCE OF SUSTAINED UPDRAFTS. MEANWHILE...FARTHER S AND E...SUSTAINED REGION OF LOW/MID-LVL WARM ADVECTION ALONG SWRN FRINGE OF THE BERMUDA HIGH WILL DRIVE TSTMS ACROSS PORTION OF ERN TX INTO CNTRL/NRN LA. THOUGH SFC-HEATING WILL LIKELY BE LIMITED...MOISTENING LLVL ENVIRONMENT AND MRGLLY 0-1KM SRH OF 100-150 M2/S2 MAY RESULT IN A BRIEFLY SUSTAIN STORM CAPABLE OF DMGG WIND OR A TORNADO. OVERALL LACK OF UPR JET SUPPORT AND THE WEAK LAPSE RATES WILL TEMPER A MORE WIDESPREAD RISK OF SVR STORMS. Read more

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