SPC AC 141223
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0723 AM CDT THU MAY 14 2009
VALID 141300Z - 151200Z
...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF SOUTHWEST TX...
A POTENT UPPER TROUGH IS ROTATING ACROSS THE GREAT LAKES REGION
TODAY...WHILE THE ASSOCIATED COLD FRONT SWEEPS EASTWARD ACROSS THE
UPPER OH VALLEY...TN VALLEY...AND LOWER MS VALLEY. TODAY IS
EXPECTED TO BE MUCH LESS CONVECTIVELY ACTIVE THAN WEDNESDAY...BUT
MAY STILL SEE POCKETS OF STRONG TO SEVERE STORMS THIS AFTERNOON AND
EVENING.
...SOUTHWEST TX...
A MOIST AND VERY UNSTABLE AIRMASS WILL ONCE AGAIN BE PRESENT THIS
AFTERNOON OVER PARTS OF CENTRAL AND SOUTHWEST TX WITH DEWPOINTS IN
THE 60S AND MLCAPE VALUES OF 2000-3000 J/KG. WEAK
FLOW...RIDGING...AND SOME CAPPING ALOFT WILL LIMIT THE AREAL
COVERAGE OF CONVECTION THROUGH MOST OF THE DAY. HOWEVER...IT
APPEARS LIKELY THAT AT LEAST ISOLATED CELLS WILL DEVELOP BY LATE
AFTERNOON ALONG THE DRYLINE FROM NEAR ABI SOUTHWARD. STORMS THAT
FORM WILL LIKELY BE ORGANIZED MULTICELLS OR SUPERCELLS WITH A RISK
OF HAIL AND DAMAGING WINDS THROUGH THE EVENING.
...PA/WV/KY...
REMNANT CONVECTIVE LINE CONTINUES TO TRACK EASTWARD ACROSS THE UPPER
OH VALLEY THIS MORNING. TRENDS IN RADAR AND LIGHTNING DATA INDICATE
THAT THE LINE HAS WEAKENED CONSIDERABLY AND IS NO LONGER SEVERE.
HOWEVER...LOW AND MID LEVEL WIND FIELDS ARE QUITE STRONG AND MORNING
RAOBS SUGGEST MARGINAL INSTABILITY IS PRESENT. A FEW HOURS OF
DAYTIME HEATING MAY BE SUFFICIENT TO REJUVENATE STORMS AND POSE A
RISK OF LOCALLY GUSTY/DAMAGING WINDS EARLY THIS AFTERNOON.
...CENTRAL GULF COAST STATES INTO FL...
A MOIST AND MODERATELY UNSTABLE AIRMASS IS IN PLACE TODAY OVER THE
SOUTHEAST STATES...WITH DEWPOINTS IN THE 60S TO LOWER 70S AND THE
POTENTIAL FOR STRONG DAYTIME HEATING. COOL TEMPERATURES ALOFT /-9
TO -11C AT 500MB/ WILL HELP TO YIELD SUFFICIENT AFTERNOON CAPE FOR A
RISK OF A FEW RATHER DISORGANIZED THUNDERSTORM CLUSTERS CAPABLE OF
DAMAGING WINDS AND HAIL.
...OK/KS/MO OVERNIGHT...
A SHORTWAVE TROUGH EVIDENT ON WATER VAPOR IMAGERY OVER THE PACIFIC
NORTHWEST WILL CROSS THE ROCKIES AND APPROACH THE CENTRAL PLAINS BY
LATE TONIGHT. STRONG SOUTHERLY LOW LEVEL WINDS WILL TRANSPORT
MOISTURE NORTHWARD AND RESULT IN ELEVATED INSTABILITY OVER MUCH OF
OK/KS/MO BY THE END OF THE FORECAST PERIOD. IT APPEARS LIKELY THE
SCATTERED THUNDERSTORMS WILL DEVELOP ACROSS THIS REGION WITH A RISK
OF HAIL IN THE STRONGER CORES.
..HART/HURLBUT.. 05/14/2009
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z
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