SWODY1
SPC AC 151231
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0731 AM CDT SUN APR 15 2007
VALID 151300Z - 161200Z
..THERE IS A SLGT RISK OF SVR TSTMS TODAY FROM THE ERN CAROLINAS
SWD INTO FL...
..SYNOPSIS...
A SURFACE CYCLONE OVER THE PIEDMONT THIS MORNING WILL MOVE NEWD AND
DEEPEN RAPIDLY IN RESPONSE TO AN AMPLIFYING SHORTWAVE TROUGH THAT
WILL PIVOT ENEWD FROM MS/AL TO OFF THE CAROLINAS BY EARLY TONIGHT.
AS THIS SYSTEM INTENSIFIES...A SURFACE COLD FRONT WILL ACCELERATE
EWD TO OFF THE NE FL/GA/SC COASTS BY 15-18Z...AND THE FRONT WILL
CLEAR THE SE FL COAST BY THIS EVENING.
..CENTRAL AND ERN CAROLINAS THROUGH MID AFTERNOON...
RICH LOW-LEVEL MOISTURE HAS OVERSPREAD THE WARM SECTOR IN ADVANCE OF
THE SURFACE LOW...WITH MID 60S BOUNDARY LAYER DEWPOINTS INTO
CENTRAL/ERN NC...AND 68-70 F DEWPOINTS FARTHER S ACROSS ERN SC INTO
THE FL PENINSULA. HOWEVER...WARM SECTOR INSTABILITY HAS BEEN
LIMITED BY POOR MID LEVEL LAPSE RATES AND RELATIVELY WIDESPREAD
RAINFALL...AND THE ONLY PROSPECTS FOR STEEPENING LAPSE RATES TODAY
WILL BE ACROSS NC ALONG THE PATH OF THE PRIMARY MID LEVEL THERMAL
TROUGH. STILL...A LARGE FRACTION OF THE TOTAL CAPE IS LOCATED BELOW
500 MB PER THE 12Z CHS SOUNDING...AND LOW-MID LEVEL VERTICAL SHEAR
REMAINS QUITE STRONG IN THE WARM SECTOR IN ASSOCIATION WITH THE
AMPLIFYING SYSTEM AND STRENGTHENING HEIGHT GRADIENTS THROUGH THE
TROPOSPHERE. LOW-LEVEL SHEAR IS EXPECTED TO BECOME EXTREME
/EFFECTIVE SRH AOA 600 M2/S2/ OVER ERN NC BY MID-LATE MORNING IN
CONJUNCTION WITH A 70 KT LLJ.
THE THREAT FOR A FEW TORNADOES AND DAMAGING GUSTS WILL CONTINUE THIS
MORNING FROM SE GA INTO THE COASTAL PLAINS OF SC...WHILE THE SEVERE
THREAT WILL GRADUALLY INCREASE THROUGH THE MORNING ACROSS
CENTRAL/ERN NC AS THE LOW LEVELS MOISTEN/DESTABILIZE. THE PRIMARY
CONVECTIVE BAND WILL LIKELY SHIFT OFF THE NC COAST FROM 18-21Z.
HOWEVER...THERE WILL BE SOME THREAT FOR ADDITIONAL STORM DEVELOPMENT
DURING THE AFTERNOON FARTHER W IN NC IN ASSOCIATION WITH LINGERING
INSTABILITY AS THE PRIMARY MID LEVEL WAVE TRAVERSES THIS AREA.
..FL PENINSULA TODAY...
A FORCED FRONTAL SQUALL LINE WILL CROSS FL FROM NW TO SE DURING THE
DAY. RELATIVELY STRONG FLOW JUST OFF THE SURFACE COULD SUPPORT A
FEW DAMAGING GUSTS WITHIN THE LINE OF STORMS...BUT THE OVERALL
SEVERE THREAT IN FL WILL BE TEMPERED BY RATHER WEAK INSTABILITY.
.THOMPSON/TAYLOR.. 04/15/2007
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