[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 210109
SWODY1
SPC AC 210107

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0807 PM CDT THU APR 20 2006

VALID 210100Z - 211200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM WEST TX ACROSS THE
ARKLATEX TO THE TN VALLEY AND NRN GA...

...SYNOPSIS...
QUASI-STATIONARY FRONT WAS SITUATED FROM WEST TX TO THE TN VALLEY
THIS EVENING WITH SEVERAL AREAS OF ONGOING VIGOROUS CONVECTION BEING
FUELED BY MOIST AND UNSTABLE AIR MASS FLOWING NWD INTO THE FRONTAL
ZONE. THE FRONT WAS ALIGNED WITH MODEST /40-50KT/ SWLY MID LEVEL
FLOW WITH ONGOING STORMS...AND CONTINUING POTENTIAL FOR DEEP
CONVECTION...TIED TO THE PASSAGE OF MID/UPPER LEVEL IMPULSES
EMBEDDED WITHIN THE SWLY FLOW ALOFT. ONE OF THESE IMPULSES WAS
CURRENTLY MOVING EAST FROM SERN NM AND WILL ENHANCE DEEP LAYER
ASCENT ACROSS THE FRONT...FROM WEST TX TO THE LOWER MS VALLEY...
THROUGH FRIDAY MORNING. A MORE ELONGATED AND LOWER AMPLITUDE
IMPULSE...AND ITS ASSOCIATED MID LEVEL WIND MAX...WERE LIFTING NEWD
FROM WRN TN TO THE LOWER OH RIVER VALLEY.

...TX TO NWRN MS...
COMPLEX MESOSCALE SITUATION EXISTS ACROSS MUCH OF WRN AND CNTRL TX
THIS EVENING WITH A NUMBER OF INTENSE SUPERCELLS AND SLOW MOVING
LINE SEGMENTS MOVING EAST FROM THE HILL COUNTRY/AUSTIN AREA TO NW OF
HOU. BULK OF THIS ACTIVITY ACROSS THE HILL COUNTRY WAS NEAR/ALONG
RESIDUAL SYNOPTIC FRONT BUT NORTH OF AN OLD OUTFLOW BOUNDARY THAT
WAS AIDING NEW STORM DEVELOPMENT WEST OF SAN ANTONIO. STRONG
DEEP-LAYER ASCENT WITH APPROACHING SHORT WAVE TROUGH...AND
INCREASING MASS INFLOW...SHOULD PROMOTE CONTINUING UPSCALE
DEVELOPMENT. EVOLVING LARGE MCS WILL DEVELOP EAST INTO LA/SRN
AR...AND NRN MS...OVER THE NEXT SEVERAL HOURS. INSTABILITY RESIDING
ALONG THE FRONT SHOULD CONTINUE TO PROMOTE STOUT UPDRAFTS WHILE
MODEST FORCING...STRONG SHEAR...AND STEEP LAPSE RATES CONTRIBUTE TO
SEVERE HAIL AND WIND POTENTIAL. BRIEF TORNADO CANNOT BE RULED OUT
FOR CELLS NEAR OR CROSSING THE FRONT...ESPECIALLY OVER THE NEXT HOUR
OR SO FOR THE CLUSTER OF STORMS MOVING EAST FROM AUSTIN AREA.

ELEVATED STORMS NEAR THE VORT CENTER MOVING TOWARD NWRN TX MAY POSE
SOME THREAT OF HAIL OR ISOLATED STRONG WIND GUSTS ACROSS NRN TX OVER
THE NEXT FEW HOURS.

...AL/GA...
LARGE MCS ACROSS NRN GA WAS BECOMING GRADUALLY LESS ORGANIZED GIVEN
WIDESPREAD ATMOSPHERIC OVERTURNING AND GRADUALLY DIMINISHING
INSTABILITY AND FORCING. HOWEVER...A FEW SEVERE STORMS/SUPERCELLS
WITH HAIL AND/OR WIND WILL REMAIN POSSIBLE ON THE FRINGES OF THE
LARGE COLD POOL WHERE UNTAPPED INSTABILITY AND WEAK ISENTROPIC LIFT
WILL PERSIST FOR A FEW MORE HOURS...GENERALLY FROM WCNTRL GA ACROSS
CNTRL AL...AND PERHAPS INTO NERN MS.

..CARBIN.. 04/21/2006