SPC AC 121949
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0249 PM CDT MON MAY 12 2008
VALID 122000Z - 131200Z
...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF WEST CENTRAL TX
THIS EVENING...
BROAD UPPER TROUGH CONTINUES TO SLOWLY DEEPEN OVER THE WESTERN
UNITED STATES TODAY...WITH UPPER RIDGE IN PLACE FROM THE SOUTHERN
PLAINS INTO THE MID MS VALLEY. THERE APPEAR TO BE TWO AREAS OF SOME
CONCERN FOR STRONG/SEVERE THUNDERSTORMS TODAY.
...WESTERN NEB/NORTHWEST KS/NORTHEAST CO...
LOW LEVEL CONVERGENCE REMAINS RATHER STRONG THIS AFTERNOON NEAR
SURFACE LOW OVER NORTHEAST CO. STRONG DAYTIME HEATING HAS RESULTED
IN STEEP LOW LEVEL LAPSE RATES AND MARGINAL SURFACE-BASED
INSTABILITY...DESPITE DEWPOINTS ONLY IN THE 30S AND 40S. SCATTERED
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP IN THIS REGION
THIS AFTERNOON WITH STRONGEST CELLS CAPABLE OF GUSTY WINDS AND HAIL.
ORGANIZED SEVERE STORMS ARE NOT ANTICIPATED TODAY.
...SOUTH TX...
FULL SUNSHINE CONTINUES OVER THE MOUNTAINS OF NORTHERN MEXICO WEST
OF DRT. LATEST VISIBLE SATELLITE IMAGERY SHOWS A FEW TCU BEGINNING
TO DEVELOP IN THIS REGION. SOUTHEASTERLY LOW LEVEL WINDS ARE
TRANSPORTING MOISTURE INTO REGION WITH DEWPOINT RISING THROUGH THE
50S AND 60S. WATER VAPOR LOOPS AND MODEL GUIDANCE SUGGEST A WEAK
MID/UPPER LEVEL JET STREAK MOVING INTO WEST TX...WHICH MAY ENHANCE
UVVS AND AID IN THE DEVELOPMENT OF ISOLATED THUNDERSTORMS LATER THIS
AFTERNOON. EASTWARD PROPAGATION OF STORMS IS PROBLEMATIC DUE TO
SIGNIFICANT CAPPING INVERSION SHOWN ON MORNING 12Z DRT SOUNDING AND
MODEL FORECAST SOUNDINGS. HOWEVER...IT APPEARS POSSIBLE THAT STORMS
THAT FORM OVER THE MEXICAN PLATEAU MAY MOVE ACROSS THE RIO GRANDE
AND INTO PARTS OF WEST CENTRAL TX THIS EVENING. IF THIS
OCCURS...SUPERCELLS CAPABLE OF LARGE HAIL AND DAMAGING WINDS WILL BE
POSSIBLE.
..HART.. 05/12/2008
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z
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