ZCZC SPCSWOD48 ALL
   ACUS48 KWNS 240900
   SPC AC 240900
   
   DAY 4-8 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0400 AM CDT THU MAY 24 2007
   
   VALID 271200Z - 011200Z
   
   ...SEVERE STORMS ARE POSSIBLE ACROSS PARTS OF THE OHIO VALLEY INTO
   THE NORTHEAST ON SUNDAY...MAY 27TH...AND ACROSS PARTS OF THE NORTH
   CENTRAL PLAINS/MISSOURI VALLEY NEXT MONDAY/TUESDAY...MAY 28/29TH...
   
   DESTABILIZATION MAY BE RATHER MODEST...AT BEST...IN THE WARM SECTOR
   OF SURFACE FRONTAL WAVE PROGGED TO SHIFT NORTHEAST OF THE GREAT
   LAKES REGION THROUGH THE ST. LAWRENCE VALLEY SUNDAY.  BUT...IT
   SHOULD BECOME SUFFICIENT...GIVEN MODERATELY STRONG WIND FIELDS AND
   MID-LEVEL FORCING FOR UPWARD VERTICAL MOTION SUGGESTED BY LATEST
   MEDIUM RANGE FORECAST GUIDANCE...TO SUPPORT DAMAGING WIND/HAIL
   POTENTIAL WITH PRE-FRONTAL SQUALL LINE OR CONVECTIVE CLUSTER ACROSS 
   PARTS OF THE UPPER OHIO VALLEY AND NORTHEAST.
   
   THEREAFTER...THE PRIMARY FOCUS FOR VIGOROUS CONVECTIVE DEVELOPMENT
   WILL SHIFT INTO THE NORTH CENTRAL STATES...AS FRONT BECOMES QUASI
   STATIONARY FROM THE NORTHERN HIGH PLAINS INTO THE MID MISSOURI
   VALLEY EARLY NEXT WEEK.  MREF SUGGESTS THAT LOW-LEVEL MOISTENING AND
   STEEPENING LAPSE RATES WILL CONTRIBUTE TO STRONG INSTABILITY ACROSS
   THIS REGION...AS DEEP LAYER SHEAR INCREASES WITH THE APPROACH OF
   NEXT SHORT WAVE IMPULSE.  UNCERTAINTY EXISTS WITH REGARD TO THE
   PROGRESSION OF UPPER FEATURE...BUT THE ENVIRONMENT IS EXPECTED TO
   BECOME SUPPORTIVE OF SUPERCELLS AND UPSCALE GROWTH INTO ONE OR MORE
   CONVECTIVE CLUSTERS NEXT MONDAY/TUESDAY.
   
   ..KERR.. 05/24/2007