Dec 21, 2011 1730 UTC Day 2 Convective Outlook
Updated: Wed Dec 21 16:47:07 UTC 2011
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20111221 1730 UTC Day 2 Outlook Graphic
Probabilistic Graphic
20111221 1730 UTC Day Probabilitic Graphic
Probability of severe weather within 25 miles of a point.
Hatched Area: 10% or greater probability of significant severe within 25 miles of a point.
   SPC AC 211644
   
   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1044 AM CST WED DEC 21 2011
   
   VALID 221200Z - 231200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF LA/MS/AL...
   
   CURRENT WATER VAPOR IMAGERY SHOWS A WELL-DEFINED SHORTWAVE TROUGH
   OVER NORTHWEST MEXICO.  THIS FEATURE WILL TRACK EAST-NORTHEASTWARD
   ACROSS SOUTH TX TONIGHT AND INTO THE LOWER MS VALLEY ON THURSDAY.  A
   SURFACE BOUNDARY IS CURRENTLY STALLED JUST OFF THE LA/MS COAST...AND
   SHOULD RAPIDLY RETURN NORTHWARD TONIGHT AS SOUTHERLY LOW LEVEL WINDS
   STRENGTHEN AHEAD OF THE APPROACHING THROUGH.  BY 22/12Z...THE
   BOUNDARY IS EXPECTED TO EXTEND FROM SOUTHERN LA INTO CENTRAL MS AND
   NORTHERN AL.  SURFACE DEWPOINTS IN THE MID 60S WILL ALSO RETURN
   NORTHWARD INTO LA/MS/AL LEADING TO THE DEVELOPMENT OF AT LEAST
   MARGINAL SURFACE-BASED INSTABILITY ALONG AND SOUTH OF THE FRONT.
   
   MODEL SOLUTIONS ARE IN GENERAL AGREEMENT THAT SURFACE CYCLOGENESIS
   WILL BE OCCURRING AT THE BEGINNING OF THE FORECAST PERIOD OVER
   LA/MS.  THE DEEPENING LOW WILL TRACK INTO NORTHERN AL BY AFTERNOON. 
   DESPITE ONLY MARGINAL CAPE...BACKING AND STRENGTHENING LOW LEVEL
   WIND FIELDS COUPLED WITH STRONG LARGE SCALE FORCING FOR
   ASCENT...WILL PROMOTE A RISK OF STRONG TO LOCALLY SEVERE STORMS. 
   SUPERCELLS APPEAR TO BE THE MOST LIKELY STORM-MODE WITH DAMAGING
   WINDS AND ISOLATED TORNADOES POSSIBLE.  LOW LEVEL MOISTURE AND
   INSTABILITY WILL WEAKEN WITH NORTHEASTWARD EXTENT INTO TN/GA WITH
   DIMINISHING SEVERE WEATHER THREATS.
   
   ..HART.. 12/21/2011
   
   CLICK TO GET WUUS02 PTSDY2 PRODUCT

   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0700Z