[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 252007
SWODY1
SPC AC 252005

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0305 PM CDT TUE APR 25 2006

VALID 252000Z - 261200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE LOWER MS
VALLEY INTO SRN TX...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF SRN MO...ERN
AR...WRN TN AND WRN KY...

...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF ERN TN...ERN
KY...WV...VA AND NC...

...LOWER MS VALLEY...

CLUSTERS OF STORMS WILL CONTINUE TO DEVELOP THE REMAINDER OF THIS
AFTERNOON ALONG AND S OF A CONVECTIVE OUTFLOW BOUNDARY FROM CNTRL
AND SRN LA THROUGH PARTS OF SRN MS AND SRN AL. THE ATMOSPHERE IS
MODERATELY UNSTABLE IN THIS REGION...BUT MODEST VERTICAL SHEAR
PROFILES ARE GENERALLY SUPPORTIVE OF MULTICELL STORMS. ISOLATED
DAMAGING WIND GUSTS AND HAIL MAY ACCOMPANY THE STRONGER ACTIVITY
THROUGH EARLY EVENING.

...SRN MO...NERN AR...THROUGH WRN TN AND WRN KY...

A COLD FRONT EXTENDS FROM THE OH VALLEY SWWD THROUGH SERN MO...AND
WRN AR. THE ATMOSPHERE IS RECOVERING IN PRE-FRONTAL WARM SECTOR IN
WAKE OF EARLIER CONVECTION WHERE TEMPERATURES ARE RISING THROUGH THE
70S AND DEWPOINTS ARE IN THE LOWER 60S. LATEST OBJECTIVE ANALYSIS
SHOWS AROUND 1000 J/KG OF MUCAPE. CONVERGENCE AND BOUNDARY LAYER
FLOW ALONG THE LEADING EDGE OF THE FRONT IS RATHER WEAK...AND RECENT
STORMS HAVE BEEN INCREASING IN POST FRONTAL REGION WHERE DEEPER
LAYER ASCENT IS OCCURRING. STORMS ARE ELEVATED OVER SWRN MO.
HOWEVER...A MID LEVEL JET SPREADING EWD THROUGH SRN PERIPHERY OF
SHORTWAVE TROUGH OVER KS IS CONTRIBUTING TO EFFECTIVE SHEAR
SUFFICIENT FOR STORMS TO TAKE ON SUPERCELL STRUCTURES WITH ISOLATED
HAIL THE MAIN THREATS. STORMS MAY INCREASE IN COVERAGE DURING THE
AFTERNOON ACROSS SERN MO AND NERN AR AND SPREAD EWD INTO WRN TN AND
WRN KY THIS EVENING AS DEEP LAYER ASCENT INCREASES DOWNSTREAM FROM
EWD ADVANCING SHORTWAVE TROUGH. A FEW STORMS MAY DEVELOP CLOSER TO
THE SURFACE FRONT WHERE THE ATMOSPHERE CONTINUES TO DESTABILIZE.
ISOLATED HAIL AND STRONG WIND GUSTS WILL BE THE PRIMARY THREATS.


...S TX...

THE CAP CONTINUES TO WEAKEN WITHIN PRE-FRONTAL WARM SECTOR ACROSS S
TX WHERE THE ATMOSPHERE HAS BECOME MODERATELY UNSTABLE WITH MLCAPE
AROUND 2500 J/KG. STORMS ARE EXPECTED TO DEVELOP IN VICINITY OF THE
FRONT WITHIN THE NEXT COUPLE HOURS OR SO AND SUBSEQUENTLY SPREAD
SEWD. DEEP LAYER VERTICAL SHEAR FROM 35 TO 40 KT IS SUFFICIENT FOR
SOME STORMS TO TAKE ON SUPERCELL STRUCTURES. THE STRONG
INSTABILITY...STEEP MID LEVEL LAPSE RATES AND POTENTIAL FOR UPDRAFT
ROTATION WILL SUPPORT THE THREAT OF VERY LARGE HAIL. SOME STORMS MAY
EVENTUALLY MERGE INTO CLUSTERS WITH AN INCREASING THREAT FOR
DAMAGING WIND GUSTS.


...ERN KY THROUGH WV...VA AND THE CAROLINAS...

CONVECTION IS EXPECTED TO CONTINUE DEVELOPING DOWNSTREAM FROM A
COUPLE OF MID LEVEL VORTICITY MAXIMA MOVING EWD THROUGH THE TN AND
OH VALLEYS. THE DOWNSTREAM ATMOSPHERE IS ONLY MARGINALLY UNSTABLE
OWING TO LIMITED LOW LEVEL MOISTURE AND MODEST MID LEVEL LAPSE
RATES. THE MARGINAL INSTABILITY WILL CONTINUE TO BE THE PRIMARY
LIMITING FACTOR. HOWEVER...SURFACE HEATING HAS CONTRIBUTED TO 20-30C
TEMPERATURE-DEWPOINTS SPREADS AND STEEP LOW LEVEL LAPSE RATES.
PRIMARY THREAT APPEARS TO BE ISOLATED STRONG TO DAMAGING WIND GUSTS
WITH CONVECTIVE LINES OR CLUSTERS AS ACTIVITY SPREADS EWD THE
REMAINDER OF THIS AFTERNOON AND EVENING.

..DIAL.. 04/25/2006