SPC AC 030736
DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0236 AM CDT THU JUL 03 2008
VALID 051200Z - 061200Z
...THERE IS A SLGT RISK OF SVR TSTMS OVER ERN ND INTO NWRN MN...
...SYNOPSIS...
LARGE SCALE PATTERN WILL REMAIN DOMINATED BY AN UPPER TROUGH OVER
THE ERN STATES. A STRONG SHORTWAVE TROUGH WILL DEAMPLIFY AS IT
CRESTS UPPER RIDGE AND MOVES THROUGH THE NRN PLAINS AND UPPER MS
VALLEY. UPPER RIDGE WILL PREVAIL FROM THE SRN ROCKIES THROUGH THE
CNTRL AND SRN PLAINS. A COLD FRONT WILL ACCOMPANY THE SHORTWAVE
TROUGH MOVING THROUGH THE NRN PLAINS. A WEAK E-W ORIENTED FRONT WILL
PERSIST FROM SRN PARTS OF THE OH OR TN VALLEY INTO THE MID ATLANTIC.
...NRN PLAINS AND UPPER MS VALLEY AREA...
BOUNDARY LAYER DEWPOINTS IN THE 60S WILL ADVECT NWD THROUGH THE NRN
PLAINS BENEATH STEEP MID LEVEL LAPSE RATES ASSOCIATED WITH A WARM
EWD ADVECTING EML. THIS WILL RESULT IN MODERATE-STRONG INSTABILITY
AS THE BOUNDARY LAYER WARMS DURING THE AFTERNOON. THE WARM EML WITH
700 MB TEMPERATURES AOA 12 C WILL RESULT IN A STRONG CAP. HOWEVER...
FORCING FOR ASCENT AND HEIGHT FALLS ATTENDING THE SHORTWAVE TROUGH
AND FRONT MAY CONTRIBUTE TO SUFFICIENT MID LEVEL COOLING FOR A FEW
STORMS TO INITIATE IN VICINITY OF THE COLD FRONT BY LATE AFTERNOON
OR EARLY EVENING. STRENGTHENING MID-UPPER FLOW ACCOMPANYING THE
UPPER TROUGH WILL RESULT IN 30-40 KT BULK SHEAR SUFFICIENT FOR SOME
STORM ORGANIZATION. ISOLATED DAMAGING WIND AND LARGE HAIL WILL BE
POSSIBLE WITH THE STRONGER STORMS. ACTIVITY MAY SPREAD INTO PARTS OF
NWRN MN OVERNIGHT.
...LOWER MS VALLEY THROUGH TN AND SRN OH VALLEYS AND MID ATLANTIC...
WEAK LAPSE RATES AND POTENTIAL FOR AREAS OF WIDESPREAD CLOUDS WILL
LIMIT MLCAPE INSTABILITY IN THIS REGION. HOWEVER...WHERE SUFFICIENT
BOUNDARY LAYER WARMING OCCURS MLCAPE COULD APPROACH 1500 J/KG.
STORMS SHOULD REDEVELOP IN WARM SECTOR AS WELL AS OVER THE HIGHER
TERRAIN AND ALONG OLD OUTFLOW BOUNDARIES. VORTICITY MAXIMA ROTATING
THROUGH UPPER TROUGH MAY ENHANCE STORM COVERAGE IN SOME AREAS.
VERTICAL WIND PROFILES AND MID LEVEL LAPSE RATES WILL BE WEAK.
HOWEVER...WHERE SUFFICIENT HEATING OCCURS...LOW LEVEL LAPSE RATES
MAY STEEPEN SUFFICIENTLY FOR A THREAT OF ISOLATED DAMAGING WIND.
..DIAL.. 07/03/2008
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NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 1100Z