[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 030559
SWODY1
SPC AC 030557

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1257 AM CDT MON APR 03 2006

VALID 031200Z - 041200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS SOUTHEAST
VIRGINIA/EASTERN NORTH CAROLINA AND NORTHEAST SOUTH CAROLINA...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE E COAST STATES FROM
THE DELMARVA REGION SSWWD INTO NERN GA...

...SYNOPSIS...
MID-LEVEL TROUGH IS FORECAST TO STRENGTHEN AND TAKE ON A MORE
NEGATIVE TILT WITH TIME AS IT MOVES EWD ACROSS THE APPALACHIANS
EARLY...AND THEN ACROSS THE E COAST STATES THROUGH THE END OF THE
PERIOD.  STRONG DEEP-LAYER WIND FIELD -- INCLUDING 70 KT MID-LEVEL
JET STREAK -- WILL MOVE ACROSS GA AND THE CAROLINAS DURING THE
AFTERNOON.

AT THE SURFACE...BOUNDARY LAYER MOISTENING WILL OCCUR DURING THE
DAY...AHEAD OF APPROACHING COLD FRONT WHICH SHOULD CREST THE
APPALACHIANS BY EARLY AFTERNOON.  AS CONVECTION
REDEVELOPS/INTENSIFIES AHEAD OF THIS BOUNDARY...THREAT FOR SEVERE
WEATHER WILL INCREASE ACROSS THE E COAST STATES FROM THE DELMARVA
REGION SWD TO GA.

...E COAST STATES...
SIGNIFICANT SEVERE WEATHER EPISODE APPEARS LIKELY THIS PERIOD FROM
MD/DE/VA SWD INTO NERN GA...AS NEGATIVELY-TILTED UPPER TROUGH MOVES
ACROSS THE ERN CONUS.  

BOUNDARY LAYER IS FORECAST TO MOISTEN THROUGH EARLY
AFTERNOON...BENEATH STEEPENING MID-LEVEL LAPSE RATES ASSOCIATED WITH
APPROACHING UPPER TROUGH.  THIS COMBINED WITH DAYTIME HEATING SHOULD
PUSH MEAN-LAYER CAPE VALUES INTO THE 1000 TO 2000 J/KG RANGE BY
EARLY AFTERNOON.  ATTM...IT APPEARS THAT CONVECTION NOW OVER THE TN
VALLEY REGION WILL RE-INTENSIFY AHEAD OF FRONT...INITIALLY FROM WRN
VA SSWWD INTO WRN SC AROUND 18Z.  

DEVELOPING STORMS SHOULD RAPIDLY BECOME SEVERE...AS STRONG
DEEP-LAYER WIND FIELD WILL BE IN PLACE ACROSS THIS REGION.  STORMS
SHOULD ORGANIZE WITH TIME INTO A LINE -- WITH EMBEDDED
LEWPS/BOWS/SUPERCELLS ACROSS VA AND NC...WHERE UPPER FORCING SHOULD
BE STRONGER.  FURTHER S INTO SC AND NERN GA...MORE ISOLATED/CELLULAR
CONVECTION IS EXPECTED...WITH SHEAR MORE THAN SUFFICIENT FOR
SUPERCELLS.

GIVEN FORECAST COMBINATION OF SHEAR AND INSTABILITY...LARGE HAIL AND
DAMAGING WINDS APPEAR LIKELY.  IN ADDITION...LOW-LEVEL SPEED SHEAR
SHOULD BE SUFFICIENT FOR TORNADOES -- WITH A THREAT FOR A FEW
STRONGER TORNADOES MOST LIKELY ACROSS THE ERN CAROLINAS AND SERN VA
WHERE MODELS SUGGEST BACKED/SSELY SURFACE WINDS AHEAD OF APPARENT
LEE TROUGH.

SEVERE THREAT IS EXPECTED TO CONTINUE INTO THE EVENING...BEFORE
STORMS MOVE OFF THE COAST INTO THE WRN ATLANTIC.

..GOSS/JEWELL.. 04/03/2006