SPC AC 081240
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0740 AM CDT SUN AUG 08 2010
VALID 081300Z - 091200Z
...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE GREAT LAKES
REGION....
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF UT/NV....
...CENTRAL/UPPER MS VALLEY...
RECENT WATER VAPOR LOOPS SHOW A SUBTLE SHORTWAVE TROUGH OVER CO/WY.
THIS FEATURE AND ITS ASSOCIATED MID/UPPER LEVEL SPEED MAX WILL TRACK
EASTWARD INTO THE CENTRAL PLAINS LATER TODAY. LIFT IN ADVANCE OF
THE TROUGH COMBINED WITH A PERSISTENT SOUTHWESTERLY LOW LEVEL JET
WILL LIKELY RESULT IN SCATTERED THUNDERSTORM DEVELOPMENT BY MID
AFTERNOON OVER PARTS OF EASTERN SD/EASTERN NEB AND WESTERN IA.
SURFACE DEWPOINTS IN THIS REGION WILL BE IN THE UPPER 60S TO LOWER
70S...WHICH COMBINED WITH TEMPERATURES WELL INTO THE 90S WILL RESULT
IN MODERATELY TO VERY UNSTABLE CONDITIONS.
INITIAL STORMS OVER SD/NEB/MN THIS AFTERNOON WILL POSE A RISK OF
BECOMING SUPERCELLULAR DUE TO STRONG EFFECTIVE SHEAR AND DEGREE OF
CAPE. LARGE HAIL AND DAMAGING WINDS APPEAR TO BE THE MAIN THREATS.
LATER TONIGHT...ACTIVITY MAY CONGEAL INTO A LARGER SCALE MCS/BOW AND
SPREAD EASTWARD INTO PARTS OF IA/WI/IL WITH A RISK OF DAMAGING
WINDS.
...UT/NV...
AN UPPER LOW ALONG THE CENTRAL CA COAST WILL TRACK SLOWLY
NORTHEASTWARD AND AFFECT PORTIONS OF THE INTERMOUNTAIN WEST BY LATE
AFTERNOON. IR IMAGERY SUGGESTS THAT CLOUDS MAY BE A PROBLEM ACROSS
THE RISK AREA...POTENTIALLY LIMITING DAYTIME HEATING AND LOW LEVEL
LAPSE RATES. HOWEVER...POCKETS OF STRONG HEATING COUPLED WITH
COOLING MID LEVEL TEMPERATURES MAY BE SUFFICIENT FOR AT LEAST
ISOLATED STRONG/SEVERE STORMS LATER THIS AFTERNOON. LOCALLY
GUSTY/DAMAGING WINDS ARE EXPECTED TO BE THE MAIN THREAT.
..HART/GARNER.. 08/08/2010
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z
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