Day 4 Outlook

ZCZC SPCSWOD48 ALL
   ACUS48 KWNS 210953
   SPC AC 210953
  
   DAY 4-8 CONVECTIVE OUTLOOK 
   NWS STORM PREDICTION CENTER NORMAN OK
   0353 AM CST MON FEB 21 2011
  
   VALID 241200Z - 011200Z
  
   ...DISCUSSION...
   AN OUTBREAK OF SEVERE THUNDERSTORMS APPEARS LIKELY ON THU/D4 FROM
   ERN OK/NERN TX EWD ACROSS MUCH OF AR...SRN MO...NRN MS...CNTRL AND
   WRN KY AND TN...AND POSSIBLY CONTINUING INTO FRI/D5 ACROSS PORTIONS
   OF THE MID ATLANTIC STATES.
  
   MODELS ARE IN GOOD AGREEMENT IN DEPICTING A POTENT UPPER SHORTWAVE
   TROUGH MOVING EWD ACROSS THE SRN PLAINS DURING THE DAY THU WITH A
   SURFACE LOW DEEPENING FROM ROUGHLY OK AT 12Z TO MO/AR BY 00Z. AHEAD
   OF THE DEEPENING LOW...A RELATIVELY WIDE MOIST/WARM SECTOR WILL BE
   IN PLACE WITH BOUNDARY LAYER DEWPOINTS IN THE 60S F. STRONG FORCING
   WITH THE UPPER TROUGH...COOLING MID LEVEL TEMPERATURES AND THE
   PRESENCE OF VERY STRONG WIND PROFILES SUGGEST SIGNIFICANT SEVERE
   WEATHER WILL BE POSSIBLE...INCLUDING TORNADOES AND VERY STRONG WINDS
   IN ADDITION TO HAIL.
  
   THE GREATEST THREAT AREA ON THU WILL LIKELY BE NEAR AND JUST S OF
   THE SURFACE LOW TRACK DURING THE LATE AFTERNOON AND EVENING HOURS.
   LATEST ITERATION OF NUMERICAL GUIDANCE SUGGESTS THAT THIS WOULD
   INCLUDE MUCH OF AR...SRN MO...FAR NRN MS...AND MUCH OF WRN KY AND
   TN.
  
   SOME SEVERE THREAT WILL LIKELY PERSIST OVERNIGHT AND CONTINUE INTO
   FRI/D5...ALTHOUGH INSTABILITY AND MOISTURE WILL BE LESS. AS
   SUCH...THE EXPECTED SEVERE THREAT FRI WILL LIKELY BE COMPRISED OF
   DAMAGING WIND GUSTS ASSOCIATED WITH AN INTENSE COLD FRONT AND A
   STRONGLY FORCED LINE OF STORMS...FROM THE DELMARVA SWD ACROSS VA.
   THESE STORMS WOULD LIKELY HAVE LITTLE INSTABILITY TO WORK WITH...AND
   WOULD BE RELATIVELY LOW TOPPED...BUT A STRONG SURFACE PRESSURE
   FALL/RISE COUPLET WOULD ENHANCE WIND POTENTIAL WITH THE LINE.
  
   AFTER THE D4 TO D5 TIME FRAME...MODEL SOLUTIONS DIVERGE RAPIDLY.
  
   ..JEWELL.. 02/21/2011