SPC AC 050731
   
   DAY 3 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0231 AM CDT TUE MAY 05 2009
   
   VALID 071200Z - 081200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE ERN PART OF THE SRN
   PLAINS TO THE OH/TN VALLEYS...
   
   ...SYNOPSIS...
   DETERMINISTIC MODELS ARE IN GENERAL AGREEMENT INDICATING A BROAD
   CYCLONIC FLOW REGIME /50-70 KT MID LEVEL WINDS/ EXTENDING FROM THE
   PACIFIC NW THROUGH THE CENTRAL PLAINS AND OH VALLEY/MID SOUTH TO
   NERN STATES ON THURSDAY.  A SHORTWAVE TROUGH...INITIALLY CENTERED
   OVER SRN MANITOBA AT 12Z THURSDAY...SHOULD UNDERGO SOME
   AMPLIFICATION AS IT TRACKS EWD ONTARIO/GREAT LAKES REGION.  ALTHOUGH
   MODELS DIFFER WITH THIS SYSTEM...THEY TEND TO AGREE WITH NEXT
   UPSTREAM SHORTWAVE TROUGH THAT SHOULD AMPLIFY ESE TOWARD THE NRN
   PLAINS BY 12Z FRIDAY.
   
   IN THE LOW LEVELS...MODELS TEND TO AGREE THAT A SURFACE TROUGH
   SHOULD EXTEND FROM THE WRN GREAT LAKES SWWD THROUGH MO TO KS AT 12Z
   THURSDAY.  THIS TROUGH WILL PROGRESS E/SEWD AND SHOULD EXTEND FROM
   THE OH VALLEY SWWD THROUGH THE MID SOUTH/AR INTO OK...POSSIBLY N TX
   BY 12Z FRIDAY.
   
   ...OH VALLEY SWWD THROUGH MID SOUTH TO SRN PLAINS...
   A COUPLE OF CLUSTERS OF TSTMS SHOULD BE ONGOING EARLY THURSDAY
   MORNING...1. ACROSS THE LOWER OH VALLEY AND THE 2. ACROSS THE
   CENTRAL PLAINS.  SWLY LOW LEVEL FLOW WILL DEVELOP FROM AR INTO THE
   OH VALLEY ON DAY 3 RESULTING IN NEWD MOISTURE RETURN AND SURFACE
   DEWPOINTS IN THE LOWER 60S REACHING SWRN OH BY LATE THURSDAY
   AFTERNOON.  SURFACE HEATING SHOULD BE STRONGEST FROM PARTS OF OK
   ENEWD THROUGH AR/SRN MO TO TN/OH VALLEYS.  MODERATE INSTABILITY WILL
   DEVELOP AHEAD OF THE SURFACE TROUGH FROM IND/OH SWWD THROUGH
   KY/TN...WHILE A VERY UNSTABLE AIR MASS IS LIKELY FROM AR INTO OK
   WITH MLCAPE 2500-3500 J/KG.  THE HIGHEST MLCAPE VALUES SHOULD BE
   LOCATED IN CENTRAL OK/N TX WHERE MOISTURE WILL BE GREATER.
   
   STRONG EFFECTIVE BULK SHEAR WILL ALREADY BE IN PLACE ACROSS THE SRN
   PLAINS AT THE START OF DAY 3...WITH EFFECTIVE BULK SHEAR INCREASING
   FROM W-E INTO THE OH/TN VALLEYS AS STRONG MID LEVELS WINDS SPREAD
   EWD AND SWLY LOW LEVEL WINDS STRENGTHEN.  THIS IS EXPECTED TO
   SUPPORT ORGANIZED SEVERE STORMS FROM SRN MO/ERN OK/AR INTO THE OH/TN
   VALLEYS FROM LATE MORNING INTO THE AFTERNOON.  FARTHER W INTO
   CENTRAL OK/N TX...A DRY LINE IS EXPECTED TO MIX EWD REACHING
   WRN...POSSIBLY CENTRAL OK TO CENTRAL TX THURSDAY AFTERNOON.  A
   STRONGER CAP ACROSS THIS REGION SHOULD TEND TO INHIBIT SURFACE BASED
   DEVELOPMENT UNTIL LATE AFTERNOON OR EARLY EVENING.  IF STORMS CAN
   DEVELOP ACROSS PARTS OF CENTRAL OK INTO N TX...THE DEGREE OF
   INSTABILITY/SHEAR VALUES WOULD SUPPORT SUPERCELLS PRODUCING
   TORNADOES AND LARGE HAIL.
   
   INCREASING SLY LLJ VEERING THURSDAY NIGHT WILL SHOULD SUPPORT
   ANOTHER MCS ACROSS PARTS OF OK/KS INTO THE OZARKS...WITH THE
   POTENTIAL FOR ISOLATED HAIL WITH THESE ELEVATED STORMS.
   
   ..PETERS.. 05/05/2009
   
   CLICK TO GET WUUS03 PTSDY3 PRODUCT

   NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0730Z