SPC AC 110730
DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0230 AM CDT MON MAY 11 2009
VALID 131200Z - 141200Z
...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF IL AND MO...
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE OH
VALLEY...SRN GREAT LAKES...MID-MS VALLEY...OZARKS...CNTRL PLAINS AND
SRN PLAINS...
...UPPER TO MID-MS VALLEY/OZARKS/SRN PLAINS...
AN UPPER-LEVEL TROUGH WILL AMPLIFY AND MOVE EWD ACROSS THE NRN
STATES AS A WELL-DEFINED MID-LEVEL JET ROUNDS THE BASE OF THE
TROUGH. AHEAD OF THE SYSTEM...RETURNING LOW-LEVEL MOISTURE SHOULD
CREATE A LARGE WARM SECTOR FROM THE SRN PLAINS NNEWD ACROSS THE MID
TO UPPER-MS VALLEY. STRONG LARGE-SCALE ASCENT WITH THE UPPER-LEVEL
TROUGH AND STRONG VERTICAL SHEAR PROFILES ASSOCIATED WITH THE
MID-LEVEL JET OVER THE WARM SECTOR SHOULD RESULT IN THE POTENTIAL
FOR A WIDESPREAD SEVERE WEATHER EVENT WEDNESDAY AND WEDNESDAY NIGHT.
EARLY IN THE PERIOD...AN MCS SHOULD BE ONGOING IN THE MID-MS VALLEY
WITH THIS CONVECTIVE CLUSTER MOVING EWD ACROSS PARTS OF THE OH
VALLEY. IN THE WAKE OF THE MCS...SFC-BASED THUNDERSTORMS SHOULD
INITIATE ALONG AND AHEAD OF A COLD FRONT WEDNESDAY AFTERNOON FROM
NCNTRL IL SWWD ACROSS MO INTO SE KS. MODEL FORECASTS REMAIN
CONSISTENT THAT THIS CONVECTION WILL ORGANIZE INTO A WELL-DEVELOPED
LINEAR MCS EWD ACROSS THE WRN PORTION OF THE OH VALLEY SWWD ACROSS
THE MID-MS VALLEY...NRN OZARKS INTO ERN OK WEDNESDAY EVENING. THE
GFS AND ECMWF ARE IN GOOD AGREEMENT WITH THE POSITION OF THE
UPPER-LEVEL TROUGH. THIS COMBINED WITH GOOD CERTAINTY CONCERNING THE
DEVELOPMENT OF NUMEROUS STORMS IN A STRONGLY SHEARED ENVIRONMENT
SUPPORTS THE ISSUANCE OF A MODERATE RISK IN IL AND MO WEDNESDAY
AFTERNOON AND EVENING. PARAMETERS ON FORECAST SOUNDINGS SUGGEST THE
ENVIRONMENT WILL BE FAVORABLE FOR A SIGNIFICANT SEVERE WEATHER EVENT
WITH A STRONGLY FORCED LINE OF INTENSE STORMS. SWWD ACROSS THE
OZARKS AND SRN PLAINS...THUNDERSTORMS SHOULD BE MORE ISOLATED DUE TO
WEAKER FORCING. A GRADUAL DROP OFF IN SEVERE REPORT COVERAGE SHOULD
OCCUR IN THE OZARKS AND SRN PLAINS FOR THIS REASON.
..BROYLES.. 05/11/2009
CLICK TO GET WUUS03 PTSDY3 PRODUCT
NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0730Z
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