[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 200111
SWODY1
SPC AC 200109

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0809 PM CDT WED APR 19 2006

VALID 200100Z - 201200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM TX...ARKLATEX...ACROSS THE
LOWER MS VALLEY TO NRN FL...

...SYNOPSIS...
OCCLUDED DEEP LAYER CYCLONE RESIDES ACROSS THE NRN PLAINS THIS
EVENING WITH EXTENSIVE FRONTAL ZONE ARCING FROM WRN LAKE SUPERIOR
SWD TO THE LOWER MS VALLEY...AND THEN SWWD ACROSS THE ARKLATEX TO
THE BIG BEND. OCCLUDED NRN SEGMENT OF THE FRONT EXTENDS FROM THE
GREAT LAKES TO WRN TN. A WARM FRONT EXTENDS SEWD ACROSS THE TN
VALLEY AND HAS BEEN STRONGLY REINFORCED BY CONVECTIVE OUTFLOW FROM
AN ACTIVE MCS OVER NRN AL. MORE WIDELY SCATTERED TSTMS EXIST ALONG
THE SERN EXTENT OF THIS BOUNDARY...NOW MOVING ACROSS SRN GA AND NERN
FL.

TRAILING PORTION OF THE FRONT....FROM THE ARKLATEX TO THE RIO GRANDE
VALLEY...IS EXPECTED TO REMAIN QUASI-STATIONARY THROUGH THE REST OF
THIS FORECAST PERIOD BENEATH MODEST SWLY FLOW ALOFT. WEAK
PERTURBATIONS EMBEDDED WITHIN THE MID LEVEL FLOW...COUPLED WITH SOME
STRENGTHENING OF THE NOCTURNAL LLJ...SHOULD PROMOTE ADDITIONAL STORM
DEVELOPMENT ALONG AND NORTH OF THE FRONT...FROM TX TO SRN AR/NRN LA
INTO EARLY THURSDAY MORNING.

...NRN MS/AL...SRN GA/FL...
INTENSE MCS ACROSS NRN/NERN AL CONTINUES TO DRIFT GENERALLY SWD
FUELED BY VERY UNSTABLE AIR MASS TO THE WEST. WHILE SOME WWD
PROPAGATION AND ATTEMPTS AT NEW DEVELOPMENT HAVE BEEN NOTED WITHIN
THE STRONG INSTABILITY AXIS WWD INTO NERN MS...GENERALLY LIMITED
LARGE SCALE FORCING BENEATH MID LEVEL RIDGE MAY BE INHIBITING MORE
WIDESPREAD SURFACE-BASED DEVELOPMENT ACROSS THE WARM SECTOR. BULK OF
ONGOING ACTIVITY WAS LIKELY BECOMING INCREASINGLY ELEVATED AS STRONG
OUTFLOW SPREADS WWD AWAY FROM THE COMPLEX AND DEEP COLD POOL.
NONETHELESS...PLUME OF STEEP LAPSE RATES AND FOCUSED FORCING NEAR
THE OUTFLOW-REINFORCED WARM FRONT...COMBINED WITH MORE THAN ADEQUATE
SHEAR TO MAINTAIN STORM UPDRAFTS...SHOULD RESULT IN AT LEAST A
COUPLE MORE HOURS OF SEVERE WEATHER. PRIMARY THREAT FROM ONGOING
STORMS WILL BE LARGE HAIL AS ACTIVITY CONTINUES TO TRACK SWD ACROSS
ERN AL AND SRN GA.

...TX ENEWD ACROSS SERN OK/NRN LA/SRN AR...
WEAK MID LEVEL SHORT WAVE TROUGH AND STRENGTHENING ISENTROPIC LIFT
ACROSS THE STATIONARY FRONT OVER TX SHOULD SUPPORT TSTMS INCREASING
ALONG AND NORTH OF THE BOUNDARY THROUGH TONIGHT. THIS PROCESS
APPEARS TO BE UNDERWAY FROM MAF TO MWL ATTM. ADDITIONAL
STORMS...ROOTED CLOSER TO THE SURFACE BOUNDARY...EXIST FROM DIMMIT
AND ZAVALA COUNTIES...WHERE A SMALL MCS MAY BE DEVELOPING...NWD
ACROSS THE HILL COUNTRY. STRONG INHIBITION ACROSS THE WARM SECTOR
AND EAST OF THE ONGOING FRONTAL ACTIVITY MAY INHIBIT ADDITIONAL
SURFACE-BASED DEVELOPMENT LATER THIS EVENING. HOWEVER...ONGOING NEAR
SURFACE-BASED STORMS WERE CERTAINLY OCCURRING IN AN ENVIRONMENT
FAVORABLE FOR INTENSE/SUSTAINED UPDRAFTS AND SOME WIND/ISOLATED
TORNADO POTENTIAL WILL EXIST WITH THIS CONVECTION NEAR THE BOUNDARY
FOR AT LEAST ANOTHER HOUR OR SO.

ELEVATED STORMS NORTH OF THE FRONT WILL POSE A LARGE HAIL THREAT AND
EXPECT THIS ACTIVITY TO EXPAND NWD/EWD ACROSS NRN TX AND INTO SRN
AR/SRN LA THROUGH DAYBREAK.

..CARBIN.. 04/20/2006