[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 101718
SWODY2
SPC AC 101717

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1217 PM CDT WED MAY 10 2006

VALID 111200Z - 121200Z

...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE MID
ATLANTIC...

...SYNOPSIS...
STRONG DEEP-LAYER CYCLONE WILL CONTINUE TO EVOLVE OVER THE UPPER
MIDWEST/GREAT LAKES REGIONS THROUGH THURSDAY...AND THEN REMAIN
ANCHORED OVER THESE AREAS AS A DEEP CLOSED LOW THROUGH THE END OF
THE WEEK. THIS PROCESS WAS ALREADY UNDERWAY AS A VIGOROUS SHORT WAVE
TROUGH...CURRENTLY CROSSING THE SRN PLAINS...PIVOTS RAPIDLY NEWD
ACROSS THE MID MS VALLEY AND INDUCES STRONG CYCLOGENESIS OVER THE
MIDWEST AND LOWER MI LATE TODAY THROUGH THURSDAY MORNING. ANOTHER
POTENT UPSTREAM VORTICITY MAXIMUM...EVIDENT IN WATER VAPOR IMAGERY
DIGGING SEWD ACROSS THE CNTRL PLAINS...WILL ROTATE THROUGH THE BASE
OF THE LARGE SCALE LOW AND THEN ACROSS THE TN VALLEY ON THURSDAY
AFTERNOON. STRONG HEIGHT FALLS ASSOCIATED WITH THIS SECONDARY SHORT
WAVE FEATURE WILL SPREAD EWD/SEWD ACROSS THE
SOUTHEAST...APPALACHIANS...AND MID ATLANTIC COASTAL PLAIN FROM
THURSDAY AFTERNOON THROUGH THURSDAY NIGHT.

AS PRIMARY SURFACE CYCLONE UNDERGOES OCCLUSION OVER LOWER MI DURING
THE DAY...ASSOCIATED COLD FRONT WILL SWEEP EAST ACROSS THE
APPALACHIANS. GIVEN STRONG DYNAMIC FORCING ASSOCIATED WITH THE
SECOND SHORT WAVE TROUGH APPROACHING THE APPALACHIANS...WEAK
SECONDARY CYCLOGENESIS IS LIKELY TO OCCUR ON THE ADVANCING COLD
FRONT IN THE LEE OF THE APPALACHIANS. THIS WAVE AND THE FRONT WILL
THEN DEVELOP ENEWD ACROSS NRN VA THROUGH THE EVENING AS THE TRAILING
PORTION OF THE COLD FRONT MOVES EWD AND OFF THE EAST COAST BY EARLY
FRIDAY.

...MID-ATLANTIC/ERN CAROLINAS...
WIDESPREAD CLOUDS AND CONVECTION ARE EXPECTED AT THE START OF THE
PERIOD WITHIN EXTENSIVE WARM CONVEYOR BELT WHICH SHOULD MOVE EAST
AND OFF THE COAST BY AFTERNOON. AT LEAST MODEST SURFACE HEATING
SHOULD DEVELOP IN THE WAKE OF MORNING RAIN/CLOUDS BENEATH MID-LEVEL
DRY SLOT FORECAST TO WRAP AROUND THE LARGER SCALE LOW FROM THE SRN
APPALACHIANS TO WV/SWRN VA. WHILE MID LEVEL LAPSE RATES WITHIN THE
DRY SLOT WILL TEND TO BE WEAK GIVEN RELATIVELY WARM TEMPERATURES IN
THE H5-H7 LAYER...SURFACE HEATING AND DEWPOINTS IN THE 60S SHOULD
CONTRIBUTE TO WEAK TO MODEST DESTABILIZATION AHEAD OF THE COLD
FRONT. MIXING AND ASCENT ALONG THE FRONT SHOULD BE ENHANCED AS
STRONG HEIGHT FALLS SPREAD EAST ATOP THE MOIST AXIS THROUGH THE LATE
AFTERNOON. THIS SHOULD PROMOTE THE DEVELOPMENT OF A RELATIVELY
LOW-TOPPED SQUALL LINE FROM SRN PA/NRN VA AREA SWD ACROSS PARTS OF
THE CAROLINAS.

DEEP LAYER VERTICAL SHEAR WILL STRENGTHEN COINCIDENT WITH THE
DEVELOPING LINE OF STORMS AND SHOULD PROVE SUFFICIENT FOR STORM
ORGANIZATION AND SUSTENANCE. SUPERCELLS AND LINE SEGMENTS SHOULD
EVOLVE FROM THE FORCED LINE OF CONVECTION AND RESULT IN SCATTERED
HAIL...DAMAGING WINDS...AND PERHAPS A TORNADO OR TWO.

FARTHER S...LOW-LEVEL CONVERGENCE AND DEEP SHEAR ALONG THE TRAILING
FRONT BECOME WEAKER...FROM SRN SC SWD ACROSS FL. HOWEVER...FRONTAL
CIRCULATION WILL MOVE INTO A VERY MOIST AND WEAKLY CAPPED
ENVIRONMENT AND A FEW TSTMS ALONG THE LENGTH OF
THE FRONT COULD PRODUCE ISOLATED DAMAGING WINDS AND/OR MARGINALLY
SEVERE HAIL.

...SERN MO ACROSS THE TN VALLEY...
MID LEVEL COLD POOL AND MODEST DYNAMIC FORCING ON CYCLONIC SHEAR
SIDE OF MID LEVEL WIND MAX WILL FOSTER LOW-TOPPED CONVECTIVE
DEVELOPMENT FROM THE MID MS VALLEY ESEWD ACROSS PARTS OF KY/TN
DURING THE AFTERNOON. DESPITE LIMITED BOUNDARY LAYER MOISTURE IN
THESE AREAS IN THE WAKE OF STRONG FRONTAL PASSAGE...SURFACE HEATING
BENEATH COLD MID LEVEL TEMPERATURES AOB -20C WILL SUPPORT WEAK
MLCAPE AND STEEP LOW THROUGH MID LEVEL LAPSE RATES. A FEW TSTM
CLUSTERS FORMING WITHIN THIS REGION MAY PRODUCE HAIL. A SMALL SLGT
RISK COULD BE INTRODUCED IN LATER OUTLOOKS IF IT APPEARS THAT HAIL
STORM COVERAGE WARRANTS HIGHER PROBABILITIES.

..CARBIN.. 05/10/2006