Categorical Graphic
Probabilistic Tornado Graphic
Probabilistic Damaging Wind Graphic
Probabilistic Large Hail Graphic

   SPC AC 031621
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1021 AM CST MON MAR 03 2008
   
   VALID 031630Z - 041200Z
   
   ...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON INTO TONIGHT FOR
   ERN LA...EXTREME SE AR...MUCH OF MS...AND WRN AL...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDS THE MDT RISK
   AREA...FROM SE TX TO THE TN VALLEY...
   
   ...LOWER MS VALLEY AREA THROUGH TONIGHT...
   A STRONG MID LEVEL TROUGH OVER W TX IS BEGINNING TO MOVE EWD PER
   LATEST WATER VAPOR IMAGERY...AND THIS SYSTEM WILL REACH THE LOWER MS
   VALLEY BY TONIGHT.  IN ADVANCE OF THE MID LEVEL WAVE...A SURFACE LOW
   IN E TX WILL DEEPEN AND MOVE NEWD TO NRN MS/TN BY THE END OF THE
   PERIOD.  A TRAILING COLD FRONT WILL LIKEWISE SWEEP EWD ACROSS E
   TX/WRN LA TODAY AND THE REMAINDER OF LA/MS/WRN AL BY 04/12Z.
   
   THE CONVECTION THIS MORNING HAS BEEN TIED LARGELY TO THE STRONG
   SURFACE COLD FRONT AS A RESULT OF RESIDUAL CONVECTIVE INHIBITION AND
   ONLY MODEST WARM SECTOR INSTABILITY.  EXPECT THE CONVECTION TO
   REMAIN ALONG THE FRONT THROUGH AT LEAST EARLY AFTERNOON.  BY MID
   AFTERNOON...LOW-LEVEL MOISTENING FROM THE S /BOUNDARY LAYER
   DEWPOINTS IN THE MID 60S/ AND DAYTIME HEATING ACROSS LA/MS WILL
   BOOST MLCAPE VALUES TO THE 500-1250 J/KG RANGE...WITH ONLY WEAK
   CONVECTIVE INHIBITION REMAINING.  EXPECT SCATTERED PRE-FRONTAL
   THUNDERSTORM DEVELOPMENT BY ROUGHLY 21Z FROM SRN LA INTO SW MS...AND
   THIS CONVECTION WILL SPREAD NEWD THROUGH THE EVENING IN ADVANCE OF
   THE COLD FRONT.
   
   THE GRADUAL INCREASE IN LOW-LEVEL MOISTURE/INSTABILITY WITHIN THE
   WARM SECTOR WILL COINCIDE WITH STRENGTHENING LOW-MID LEVEL WINDS AND
   VERTICAL SHEAR IN ADVANCE OF THE DEEPENING CYCLONE.  FORECAST
   HODOGRAPHS SHOW LARGE LOOPING STRUCTURES IN THE PRESENCE OF WEAK TO
   MODERATE SURFACE-BASED INSTABILITY...RESULTING IN EFFECTIVE SRH OF
   300-600 M2/S2 BY THIS EVENING IN THE WARM SECTOR ACROSS LA AND WRN
   MS.  THE ENVIRONMENT WILL BE FAVORABLE FOR SUPERCELLS WITH
   TORNADOES...SOME OF WHICH COULD BE STRONG.  OTHERWISE...SOME FORM OF
   THE ONGOING FRONTAL CONVECTION AND/OR EVENING SUPERCELLS WILL
   PERSIST THROUGH THE PERIOD...REACHING WRN/CENTRAL AL BY LATE
   TONIGHT.  EMBEDDED SUPERCELL AND BOWING STRUCTURES WILL BE POSSIBLE
   THROUGH THE NIGHT...WITH THE CONTINUED POTENTIAL FOR DAMAGING WINDS
   AND A FEW TORNADOES.
   
   ..THOMPSON/SMITH.. 03/03/2008
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z