SPC AC 081730
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1230 PM CDT FRI SEP 08 2006
VALID 091200Z - 101200Z
...NO SVR TSTM AREAS FORECAST...
...SYNOPSIS...
A SHORTWAVE TROUGH WILL AMPLIFY SEWD INTO THE GREAT LAKES AND NERN
STATES SATURDAY. THIS WILL RESULT IN A COLD FRONT CURRENTLY FROM
SERN CANADA SWWD INTO THE GREAT LAKES CONTINUING SEWD INTO THE NERN
U.S. AND OH VALLEY. SWRN PORTION OF THIS BOUNDARY WILL LIKELY SLOW
OR STALL AS A SHORTWAVE TROUGH NOW OVER THE GREAT BASIN ADVANCES EWD
INTO THE CNTRL HIGH PLAINS.
...NERN STATES AND OH VALLEY...
SURFACE HEATING AHEAD OF COLD FRONT AND LOW LEVEL DEWPOINTS IN THE
50S WILL CONTRIBUTE TO MODERATE INSTABILITY SATURDAY FROM PORTIONS
OF THE NERN U.S. INTO THE OH VALLEY. HOWEVER...MLCAPE SHOULD REMAIN
GENERALLY BELOW 1200 J/KG OWING TO MODEST LOW LEVEL MOISTURE AND
700-500 MB LAPSE RATES. STORMS WILL LIKELY REDEVELOP ALONG THE FRONT
BY LATE MORNING OR EARLY AFTERNOON AND SUBSEQUENTLY SPREAD SEWD.
STRONGER WIND PROFILES WILL REMAIN IN THE POST FRONTAL ENVIRONMENT
IN ASSOCIATION WITH SEWD ADVANCING SHORTWAVE TROUGH. WIND PROFILES
IN VICINITY OF FRONT WILL REMAIN UNIDIRECTIONAL WLY WITH 25 TO 30KT
IN THE 850 TO 300 MB LAYER AND MODEST VERTICAL SHEAR. THIS SUGGEST
STORM MODE SHOULD REMAIN MULTICELLULAR...BUT WITH SOME STORMS
EVOLVING INTO LINE SEGMENTS OR CLUSTERS AS THEY MOVE SEWD. ISOLATED
DAMAGING WIND GUSTS AND HAIL WILL BE THE MAIN THREATS. THIS AREA
WILL BE MONITORED FOR A POSSIBLE UPGRADE TO SLIGHT RISK IN DAY 1
OUTLOOKS.
...CNTRL PLAINS...
CONVECTION WILL INCREASE WITHIN ZONE OF WARM ADVECTION AND LARGE
SCALE AHEAD OF EWD ADVANCING SHORTWAVE TROUGH. WEAK CYCLOGENESIS AND
A 30 TO 35 KT SLY LOW LEVEL JET ARE FORECAST IN ASSOCIATION WITH
THIS FEATURE ACROSS KS. THIS WILL ENHANCE ISENTROPIC ASCENT N OF SWD
ADVANCING FRONT FROM NRN KS INTO NEB WHERE PRECIPITATION SHOULD BE
MORE WIDESPREAD BUT INSTABILITY MORE LIMITED. BEST CHANCE FOR SOME
DESTABILIZATION WILL EXIST S OF FRONT WHERE POCKETS OF SURFACE
HEATING MAY DEVELOP. HOWEVER...CAPE WILL BE LIMITED BY MODEST LAPSE
RATES AND LOW LEVEL MOISTURE. LOW LEVEL WIND PROFILES ASSOCIATED
WITH LOW LEVEL JET AND BACKED FLOW E OF SURFACE LOW WILL CONTRIBUTE
TO HODOGRAPHS FAVORABLE FOR UPDRAFT ROTATION OVER PORTIONS OF CNTRL
OR N CNTRL KS. HOWEVER...THE BEST LOW LEVEL SHEAR WILL MOST LIKELY
REMAIN IN THE CLOUDY...COOLER AIR. THIS ALONG WITH MODEST
INSTABILITY AND LAPSE RATES IN WARM SECTOR SUGGEST SEVERE THREAT
SHOULD REMAIN LOW.
..DIAL.. 09/08/2006
CLICK TO GET WUUS02 PTSDY2 PRODUCT
NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0800Z
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