[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 211728
SWODY2
SPC AC 211727

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1227 PM CDT FRI APR 21 2006

VALID 221200Z - 231200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE MIDDLE AND SRN
ATLANTIC COASTAL STATES...

...SYNOPSIS...
LARGE MID/UPPER TROUGH WILL PROGRESS SLOWLY EWD ACROSS THE WRN U.S.
THIS PERIOD...WHILE SECOND TROUGH -- COMPRISED OF A DEEP UPPER LOW
OVER THE GREAT LAKES REGION AND A MORE PROGRESSIVE SRN STREAM
SHORT-WAVE TROUGH OVER THE SOUTHEAST -- ALSO MOVES EWD THROUGH THE
PERIOD.  

THOUGH SCATTERED THUNDERSTORMS ARE EXPECTED ACROSS THE WRN U.S.
AHEAD OF UPPER TROUGH...MAIN SEVERE THREAT THIS PERIOD SHOULD EXIST
OVER THE ATLANTIC COASTAL STATES AHEAD OF ERN TROUGH/COLD FRONT. 

...SRN AND MIDDLE ATLANTIC COASTAL REGION...
WIDESPREAD PRECIPITATION/THUNDERSTORMS WILL LIKELY BE ONGOING AT THE
START OF THE PERIOD ALONG AND E OF THE APPALACHIANS...AHEAD OF
EWD-MOVING COLD FRONT AND ASSOCIATED SHORT-WAVE TROUGH CROSSING THE
CENTRAL AND SRN APPALACHIANS REGION EARLY IN THE PERIOD.  WIDESPREAD
CLOUDS/PRECIPITATION SHOULD LIMIT HEATING/DESTABILIZATION E OF THE
MOUNTAINS TO A GREAT DEGREE...THOUGH AT LEAST MARGINAL INSTABILITY
/500 TO 1000 J/KG MEAN-LAYER CAPE/ IS EXPECTED BY EARLY
AFTERNOON...SUPPORTED BY MOIST BOUNDARY LAYER. THIS SHOULD RESULT
IN AN INCREASE/INTENSIFICATION OF STORMS AHEAD OF BOUNDARY FROM
MIDDAY THROUGH THE AFTERNOON AS CONVECTION SPREADS EWD TOWARD THE
ATLANTIC COAST.

THOUGH FORECAST TO BE FAIRLY UNIDIRECTIONAL/MERIDIONAL...DEEP-LAYER
WIND FIELD WILL BE MODERATELY STRONG/SUFFICIENT FOR ORGANIZED
CONVECTION.  WHERE POCKETS OF GREATER INSTABILITY CAN
DEVELOP...EXPECT STORMS TO BECOME SEVERE...WITH HAIL AND LOCALLY
DAMAGING WINDS POSSIBLE -- AND PERHAPS A TORNADO.  THREAT MAY
CONTINUE INTO THE EVENING -- PARTICULARLY ACROSS THE ERN
CAROLINAS...BEFORE STORMS DIURNALLY WEAKEN/MOVE OFFSHORE.

...FL...
STORMS ARE FORECAST TO DEVELOP ACROSS ERN FL -- MAINLY OVER COASTAL
AREAS AS WLY/SWLY LOW-LEVEL FLOW OVER THE PENINSULA AHEAD OF FRONT
SUGGESTS THAT MAIN ZONE OF LOW-LEVEL CONVERGENCE WILL EVOLVE IN
ASSOCIATION WITH E COAST SEA BREEZE BOUNDARIES.  SUFFICIENT SHEAR
AND INSTABILITY WILL EXIST FOR STRONG/LOCALLY SEVERE STORMS...ALONG
WITH ACCOMPANYING THREAT FOR MARGINAL HAIL/LOCALLY DAMAGING
WINDS...AND POSSIBLY AN ISOLATED TORNADO NEAR SURFACE BOUNDARIES.

..GOSS.. 04/21/2006