SPC AC 260531
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1231 AM CDT WED AUG 26 2009
VALID 261200Z - 271200Z
...NO SVR TSTM AREAS FORECAST...
...SRN AND CNTRL PLAINS...
SEVERAL CLUSTERS OF THUNDERSTORMS SHOULD BE ONGOING THIS MORNING
FROM WRN KS EWD INTO NRN MO ALONG AND NORTH OF A QUASI-STATIONARY
FRONTAL BOUNDARY. BY MIDDAY...THE BOUNDARY SHOULD BE LOCATED FROM
THE TX PANHANDLE TO A SFC LOW IN NRN OK EWD INTO WRN MO. THIS
BOUNDARY SHOULD BE THE FOCUS FOR THE DEVELOPMENT OF SFC-BASED
CONVECTION THIS AFTERNOON. DUE TO SFC DEWPOINTS IN THE LOWER 70S
F...MODERATE TO STRONG INSTABILITY SHOULD BE PRESENT ACROSS MUCH OF
THE ERN HALF OF KS AND NRN OK WHERE THE ETA-KF SHOW MLCAPE VALUES IN
THE 3000 TO 3500 J/KG RANGE. IN SPITE OF THE STRONG
INSTABILITY...FORECAST SOUNDINGS KEEP A CAPPING INVERSION IN PLACE
ACROSS MUCH OF THE WARM SECTOR SUGGESTING DEVELOPMENT MAY REMAIN
ISOLATED INTO THE EVENING. IF A CLUSTER OF STRONG THUNDERSTORMS CAN
DEVELOP ALONG THE INSTABILITY AXIS...THE MOST LIKELY AREA WOULD BE
IN NRN OK AND SRN KS WHERE ETA-KF FORECAST SOUNDINGS HAVE 20-25 KT
OF 0-6 KM SHEAR AT 00Z. THIS IS ON THE LOW-END FOR ORGANIZED
THUNDERSTORMS...HOWEVER STEEP LOW-LEVEL LAPSE RATE AND STRONG
INSTABILITY MAY BE STILL SUFFICIENT FOR ISOLATED DAMAGING WIND
GUSTS. IN ADDITION...A PLUME OF STEEP MID-LEVEL LAPSE RATES IS
FORECAST TO EXTEND INTO WRN OK WHICH COULD HELP SUPPORT A HAIL
THREAT AS WELL. AN UPGRADE TO SLIGHT RISK MAY BE NECESSARY ACROSS
PARTS OF THE CNTRL AND SRN PLAINS ONCE CONFIDENCE INCREASES AND THE
AREA WITH THE GREATEST POTENTIAL BECOMES BETTER-DEFINED.
..BROYLES/SMITH.. 08/26/2009
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z
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