[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 251619
SWODY1
SPC AC 251617

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1117 AM CDT TUE APR 25 2006

VALID 251630Z - 261200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM CENTRAL TX ACROSS THE
LOWER MS AND TN VALLEYS INTO NC...

MODERATELY FAST ZONAL FLOW PATTERN HAS DEVELOPED ACROSS MUCH OF THE
CENTRAL/EASTERN UNITED STATES TODAY...WITH 30-40 KNOT WESTERLY FLOW
ALOFT FROM OK/TX INTO THE CAROLINAS.  PRIMARY SURFACE BAROCLINIC
ZONE EXTENDS FROM CENTRAL TX INTO SOUTHERN MO...THEN EASTWARD ACROSS
KY INTO SOUTHERN VA.  WIDESPREAD MOIST AND AT LEAST MARGINALLY
UNSTABLE AIR MASS WILL LIKELY YIELD SCATTERED THUNDERSTORMS OVER A
LARGE AREA THIS AFTERNOON.

...TX/LA/SRN MS...
SURFACE COLD FRONT CONTINUES TO SURGE SOUTHWARD ACROSS CENTRAL TX
THIS MORNING...WHILE REMNANT OUTFLOW BOUNDARY SAGS SOUTHWARD INTO
NORTHERN LA.  MORNING VISIBLE SATELLITE IMAGERY SUGGESTS THAT
MODERATE DAYTIME HEATING WILL OCCUR ALONG AND SOUTH OF BOUNDARIES IN
REGION OF NEAR 70F SURFACE DEWPOINTS.  AFTERNOON MLCAPE VALUES WILL
LIKELY EXCEED 2500 J/KG ACROSS THIS REGION.  SCATTERED THUNDERSTORMS
ARE EXPECTED TO DEVELOP ALONG BOUNDARIES FROM CENTRAL TX INTO
NORTHERN LA DURING THE MID/LATE AFTERNOON.  THIS ACTIVITY WILL POSE
A THREAT OF LARGE HAIL AND DAMAGING WINDS.  INCREASING DEEP LAYER
VERTICAL SHEAR PROFILES THROUGH THE DAY MAY ALSO SUPPORT ISOLATED
SUPERCELL STRUCTURES CAPABLE OF VERY LARGE HAIL.  REFER TO MCD
NUMBER 651 FOR SHORT TERM DETAILS OF THIS AREA.

...ERN AR/WRN TN/WRN KY/NRN MS...
WIDESPREAD MID/HIGH CLOUDS PERSIST THIS MORNING OVER MUCH OF AR INTO
WRN TN/KY AND NORTHERN MS.  THESE CLOUDS ARE REMNANTS OF OVERNIGHT
MCS WHICH HAS DIMINISHED.  RELATIVELY STRONG HEATING WILL BE
POSSIBLE ACROSS THIS REGION THIS AFTERNOON...ALLOWING AIR MASS TO
DESTABILIZE WITH MLCAPE VALUES UP TO 2000 J/KG EXPECTED. 
CONSIDERABLE UNCERTAINTY EXISTS REGARDING FOCUS FOR INITIATION. 
HOWEVER...PARAMETERS SUGGEST A THREAT OF ISOLATED SEVERE STORMS WITH
HAIL AND DAMAGING WINDS IN THIS REGION IF CONVECTION CAN DEVELOP.

...CENTRAL/EASTERN KY/TN INTO CENTRAL APPALACHIANS...
MCV FROM OVERNIGHT THUNDERSTORMS IS NOW OVER WESTERN KY.  THIS
FEATURE WILL TRACK EASTWARD ALONG SURFACE BAROCLINIC ZONE...POSSIBLY
AIDING THE DEVELOPMENT OF SCATTERED THUNDERSTORMS THIS AFTERNOON. 
STRONG HEATING IN THIS REGION ALONG WITH SUFFICIENT FLOW ALOFT WILL
SUPPORT A RISK OF STRONG TO ISOLATED SEVERE STORMS CAPABLE OF
DAMAGING WINDS AND HAIL.  REFER TO MCD NUMBER 650 FOR FURTHER
DETAILS.

...VA/NC...
STRONG DAYTIME HEATING WILL OCCUR THROUGHOUT THIS REGION TODAY...AS
DEWPOINTS REMAIN IN THE 50S.  MODEL FORECAST SOUNDINGS SHOW MLCAPE
VALUES OF 500-1500 J/KG WITH RELATIVELY STRONG WESTERLY FLOW ALOFT. 
VERTICAL SHEAR PROFILES SUPPORT A RISK OF ORGANIZED/ISOLATED SEVERE
STORMS FROM SOUTHERN VA INTO NC...BUT WEAK CAPE VALUES ARE A
MITIGATING FACTOR.  DAMAGING WINDS APPEAR TO BE THE MAIN THREAT WITH
MORE SUSTAINED CELLS.

..HART/GRAMS.. 04/25/2006