SPC AC 231619 DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1019 AM CST FRI FEB 23 2007
VALID 231630Z - 241200Z
...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON THROUGH TONIGHT ACROSS PARTS OF SOUTH CENTRAL KS...WESTERN AND CENTRAL OK...AND NORTHWEST TX......
...THERE IS A SLGT RISK OF SVR TSTMS CENTRAL NEB INTO CENTRAL TX...
VIGOROUS TROUGH INLAND THIS AM SWRN U.S. ON TRACK TO IMPACT THE SRN PLAINS...PARTICULARLY TONIGHT. MODELS ARE IN GENERAL AGREEMENT ON TIMING AND LOCATION OF SURFACE CYCLOGENESIS WITH LOW DEVELOPING SERN CO THIS AFTERNOON AND THEN DEEPENING RAPIDLY TONIGHT INTO WRN KS WITH APPROACH OF THE INTENSE UPPER TROUGH.
LITTLE CHANGE IN THINKING FROM PREVIOUS OUTLOOK...AS THE ONLY QUESTION ON POTENTIAL FOR A SEVERE THUNDERSTORM/TORNADO OUTBREAK IS THE THERMODYNAMIC ENVIRONMENT.
THE 40-50KT LOW LEVEL JET CURRENTLY OVER SRN HIGH PLAINS CONTINUES TO INCREASE GULF MOISTURE NWD SO THAT BY LATE AFTERNOON LOW/MID 50 DEWPOINTS WILL SPREAD THRU ERN TX PANHANDLE/WRN OK INTO SWRN KS WITH NEAR 50 DEWPOINTS TO SWRN NEB/KS BORDER. GIVEN THE CLOUD COVER THE AIR MASS WILL ONLY SLOWLY DESTABILIZE THIS AFTERNOON...HOWEVER WITH THE MID LEVEL COOLING/STEEPENING LAPSE RATES SPREADING EWD INTO SRN HI PLAINS BY THIS EVENING MLCAPES WILL CLIMB TO AROUND 1000 J/KG E OF DRY LINE WHICH IS EXPECTED TO EXTEND FROM DEEPENING LOW SERN CO/WRN KS SWD THRU ERN TX PANHANDLE INTO SWRN TX.
OVERNIGHT THE MODELS BASICALLY AGREE THAT AN INTENSE LINE OF SEVERE THUNDERSTORMS WILL DEVELOP ERN TX PANHANDLE AND SPREAD INTO WRN OK/NWRN TX AS 110-120KT 500 WIND MAX DRIVES EWD INTO SWRN TX. IN ADVANCE OF THE DEVELOPMENT OF THIS SQUALL LINE THE MORE CONDITIONAL THREAT EXISTS FOR TORNADIC SUPERCELLS BY LATE THIS AFTERNOON/EARLY EVENING ALONG AND JUST TO EAST OF THE DRY LINE FROM TX PANHANDLE INTO WRN KS WHERE CAP WEAKENS SUFFICIENTLY TO SUPPORT SURFACE BASED INITIATION. ANY STORM THAT FORMS IN THIS AREA EXPECTED TO QUICKLY BECOME SUPERCELLULAR WITH ACCOMPANYING LARGE HAIL AND A TORNADO THREAT. THE VERY STRONG SHEAR PROFILES IN PLACE BY THIS EVENING SUPPORT POTENTIAL FOR STRONG TORNADOES...PROVIDED AIR MASS DEVELOPS SUFFICIENT INSTABILITY.
A MORE ORGANIZED WIND DAMAGE THREAT...POTENTIALLY SIGNIFICANT...INCREASES OVERNIGHT AS A STRONGLY FORCED SQUALL LINE DRIVES EWD AHEAD OF THE INTENSE TROUGH. ALONG WITH WIND DAMAGE THERE WILL ALSO BE THREAT OF EMBEDDED SUPERCELLS/TORNADOES. THIS SQUALL LINE EXPECTED TO MAKE IT AS FAR E AS SCENTRAL KS/ERN OK NCENTRAL TX BY 12Z SAT.
..HALES/GUYER.. 02/23/2007
