[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 251236
SWODY1
SPC AC 251234

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0734 AM CDT TUE APR 25 2006

VALID 251300Z - 261200Z

...THERE IS A SLGT RISK OF SVR TSTMS TODAY FROM SRN AND ERN TX
ACROSS THE LOWER MS VALLEY TO NC....

...SYNOPSIS...
A NRN STREAM TROUGH IS DIGGING SEWD OVER THE GREAT LAKES...AND THE
REMNANTS OF A SRN STREAM TROUGH ARE EJECTING EWD FROM THE HIGH
PLAINS IN A CONFLUENT FLOW REGIME.  A WEAK SURFACE WAVE WILL DEVELOP
EWD IN ADVANCE OF THESE MID LEVEL TROUGHS...ALONG A LOW-LEVEL
BAROCLINIC ZONE FROM KY TO NC. SW OF THE SURFACE WAVE...THE COLD
FRONT WILL MOVE SEWD ACROSS TX/AR/LA.  THE SURFACE FRONT...ALONG
WITH A RESIDUAL OUTFLOW BOUNDARY FROM A WEAKENING MCS IN AR...WILL
FOCUS FOR STRONG/SEVERE THUNDERSTORM DEVELOPMENT TODAY INTO EARLY
TONIGHT.

...SRN AND ERN TX/LA AREA...
THE COLD FRONT IS MOVING SEWD ACROSS NRN AND CENTRAL TX...AND THIS
FRONT SHOULD EXTEND FROM SRN AR ACROSS NW LA AND SE/S CENTRAL TX BY
MID AFTERNOON. ADDITIONALLY...AN OUTFLOW BOUNDARY FROM ONGOING
STORMS IN AR/SE OK WILL MOVE SWD AND HELP FOCUS ADDITIONAL
CONVECTIVE DEVELOPMENT ACROSS NE TX AND NRN LA TODAY.  SW OF THE
OUTFLOW BOUNDARY AND AHEAD OF THE COLD FRONT...DAYTIME
HEATING...BOUNDARY LAYER DEWPOINTS OF 68-72 F AND 7-8 C/KM MID LEVEL
LAPSE RATES WILL SUPPORT MLCAPE VALUES OF 2500-3000 J/KG.  FORECAST
SOUNDINGS ACROSS S CENTRAL TX APPEAR SUPPORTIVE OF SUPERCELLS ALONG
THE FRONT THIS AFTERNOON ONCE CONVECTIVE INHIBITION WEAKENS...WITH
MULTICELLULAR CONVECTION EXPECTED FARTHER NE ACROSS E TX/LA.  LARGE
HAIL AND A FEW DAMAGING GUSTS WILL BE THE MAIN SEVERE THREATS WITH
THESE STORMS THIS AFTERNOON...AND THE SEVERE THREAT SHOULD DIMINISH
LATER THIS EVENING. 

...ERN AR/NRN MS AND AL/TN AREA...
THE CONVECTION AND ASSOCIATED COLD POOL OVER AR...AND A SEPARATE MCV
OVER SE MO...MAY PERSIST AND SPREAD EWD/SEWD DURING THE DAY ACROSS
NW MS AND WRN TN.  INSTABILITY WILL BE SOMEWHAT WEAKER THIS AREA
COMPARED TO TX...BUT ISOLATED DAMAGING DOWNBURST WINDS AND
MARGINALLY SEVERE HAIL WILL BE POSSIBLE DURING THE DAY AS THE LOW
LEVELS DESTABILIZE.  THE SEVERE THREAT WITH THIS CONVECTION WILL
LIKELY DIMINISH THIS EVENING.

...NC AREA THIS AFTERNOON/EVENING...
A REMNANT MCV OVER ERN TN WILL MOVE EWD INVOF OF A QUASI-STATIONARY
FRONT ACROSS NC.  DAYTIME HEATING WILL PROMOTE THE DEVELOPMENT OF A
RELATIVELY DEEP BOUNDARY LAYER AND STEEP LOW-LEVEL LAPSE RATES E OF
THE MOUNTAINS AND S OF THE FRONT...ALONG WITH AT LEAST WEAK
SURFACE-BASED INSTABILITY.  DEEP LAYER WLY PROFILES WITH SUBSTANTIAL
SPEED INCREASE WITH HEIGHT ALOFT MAY SUPPORT A FEW MARGINAL
SUPERCELL OR BOW TYPE STORMS THIS AFTERNOON INTO THIS EVENING NEAR
THE FRONTAL ZONE.  ISOLATED DAMAGING GUSTS AND MARGINALLY SEVERE
HAIL WILL BE THE MAIN SEVERE THREATS.

..THOMPSON/TAYLOR.. 04/25/2006