ZCZC SPCSWOD48 ALL
   ACUS48 KWNS 231003
   SPC AC 231003
   
   DAY 4-8 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0403 AM CST MON FEB 23 2009
   
   VALID 261200Z - 031200Z
   
   THE MEDIUM RANGE MODELS BEGIN THE DAY 4 TO 8 PERIOD WITH A ZONAL
   FLOW PATTERN IN PLACE. A VERY SUBTLE UPPER-LEVEL TROUGH IS FORECAST
   TO MOVE EWD ACROSS THE MS VALLEY THURSDAY/DAY 4 AND ACROSS THE ERN
   SEABOARD FRIDAY. IN RESPONSE TO THIS SYSTEM...A WELL-DEVELOPED
   LOW-LEVEL JET IS FORECAST TO TRANSPORT MOISTURE NWD INTO THE OZARKS.
   LARGE-SCALE ASCENT WITH THE UPPER-LEVEL TROUGH AND LIFT ASSOCIATED
   WITH THE LOW-LEVEL JET SHOULD PROMOTE THUNDERSTORM DEVELOPMENT
   ACROSS THE OZARKS AND POSSIBLY THE LOWER OH VALLEY DURING THE DAY ON
   THURSDAY. THIS ACTIVITY SHOULD SHIFT EWD ACROSS THE OH VALLEY AND
   MID-MS VALLEY THURSDAY NIGHT REACHING THE ERN SEABOARD AND GULF
   COAST STATES ON FRIDAY. THE GREATEST POTENTIAL FOR ISOLATED SEVERE
   STORMS APPEARS TO BE ON THURSDAY ACROSS THE OZARKS WHERE SFC
   DEWPOINTS COULD BE IN THE 50S F. HOWEVER...DUE TO WEAK
   INSTABILITY...THE THREAT DOES NOT WARRANT AN OUTLOOK AREA ATTM.
   
   BEYOND FRIDAY/DAY 5...MODEL FORECASTS ARE IN GENERAL AGREEMENT
   BRINGING AN UPPER-LEVEL TROUGH INTO THE CNTRL U.S. SATURDAY/DAY 6.
   AHEAD OF THIS TROUGH...MOISTURE AND INSTABILITY SHOULD RETURN NWD
   INTO THE GULF COAST STATES. THIS COMBINED WITH STRONG VERTICAL SHEAR
   ASSOCIATED WITH A BROAD MID-LEVEL JET MAY PROMOTE SEVERE
   THUNDERSTORM DEVELOPMENT SATURDAY AFTERNOON. HOWEVER...THE TIMING
   AND AMPLITUDE OF THE UPPER-LEVEL TROUGH REMAINS HIGHLY QUESTIONABLE.
   PREDICTABILITY APPEARS TO LOW FOR AN OUTLOOK AREA ATTM.
   
   ..BROYLES.. 02/23/2009

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