SWODY1
SPC AC 161243
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0643 AM CST SAT FEB 16 2008
VALID 161300Z - 171200Z
..THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF ERN/SRN TX AND
WRN/SRN LA...
..THERE IS A SLGT RISK OF SVR TSTMS FROM CNTRL TX INTO THE LWR MS
VLY...
..SYNOPSIS...
UPPER LOW NOW NEAR ELP WILL CONTINUE E/ENE ACROSS THE REMAINDER OF
WEST TX TODAY...BEFORE ACCELERATING NE TOWARD THE MO OZARKS
TONIGHT/EARLY SUNDAY. AT THE SFC...LOOSELY-CONSOLIDATED LOW NOW
FORMING ALONG STALLED FRONT IN S CNTRL TX EXPECTED TO STRENGTHEN AND
DEVELOP NNE ALONG THE BOUNDARY THROUGH THE DAY. THE LOW SHOULD
REACH THE PRX AREA BY EVENING AS DIFFUSE MARITIME WARM FRONT...NOW
EXTENDING NW/SE ACROSS SE TX...LIFTS N INTO CNTRL LA. THE LOW
SHOULD CONTINUE NNE INTO CNTRL MO BY 12Z SUNDAY AS INCREASING WLY
FLOW S OF LOW ACCELERATES ITS TRAILING COLD FRONT E/SE INTO WRN
TN/CNTRL MS AND SE LA.
..ERN/SRN TX INTO WRN/SRN LA...
SEASONABLY WARM AND VERY HUMID AIR WILL BE PRESENT TODAY E OF SFC
FRONT NOW STALLING ALONG A NNE/SSW AXIS E OF THE I-35 CORRIDOR OVER
SRN AND ERN TX. THIS RICH BOUNDARY LAYER AIR WILL EXTEND NE TO
VICINITY OF DIFFUSE WARM FRONT NOW NEAR CLL/BPT.
SHORTWAVE RIDGING AND EXISTING EML DOWNSTREAM FROM APPROACHING UPR
LOW LIKELY WILL KEEP MOST OF REGION CAPPED TO DEEP CONVECTIVE
DEVELOPMENT THROUGH MUCH OF THE DAY. WITH TIME...HOWEVER...
COMBINATION OF SFC HEATING AND INCREASING LARGE SCALE ASCENT
EXPECTED TO SUPPORT TSTM DEVELOPMENT ALONG AND POSSIBLY IMMEDIATELY
AHEAD OF NNE/SSW FRONT AS THAT BOUNDARY BEGINS TO ACCELERATE E AS A
COLD FRONT...AND SBCAPE INCREASES TO AROUND 1500 J/KG.
WITH 500 MB SSW FLOW INCREASING TO AOA 60 KTS AND 50 KT SLY FLOW
PERSISTING JUST ABOVE THE SFC...SETUP WILL BE FAVORABLE FOR
DEVELOPMENT OF BACK-BUILDING BANDS OF SUPERCELLS THAT SHOULD FAIRLY
QUICKLY MERGE INTO AN EXTENSIVE SQLN. EMBEDDED STORMS WITHIN THESE
BANDS COULD YIELD A FEW STRONG TORNADOES...IN ADDITION TO
DESTRUCTIVE OUTFLOW WINDS...GIVEN LONG/HOOKED HODOGRAPHS WITH 0-1 KM
SRH AROUND 350 M2/S2. LARGE HAIL MAY ALSO OCCUR...ESPECIALLY ON SRN
END OF SQLN IN S CNTRL TX...WHERE SBCAPE SHOULD EXCEED 2000 J/KG. A
SIGNIFICANT TORNADO THREAT WOULD ALSO EXIST WITH ANY DISCRETE STORMS
THAT FORM IN AREA OF WEAKENING CIN IMMEDIATELY AHEAD OF SQLN.
WITH THE LOW LEVEL MOISTURE RETURN LIKELY TO CONTINUE AHEAD OF THE
SQLN DURING THE OVERNIGHT ACROSS LA...THE THREAT FOR HIGH WIND AND
ISOLATED STRONG TORNADOES COULD CONTINUE THROUGH EARLY
SUNDAY...ESPECIALLY OVER WRN AND SRN LA.
..W CNTRL/NW TX...
SCTD ELEVATED TSTMS EXPECTED TO PERSIST FROM NW TO S CNTRL TX
THROUGH ABOUT MID AFTN IN AREA OF WAA/ASCENT ON WRN EDGE OF
STRENGTHENING SLY LLJ. SUFFICIENT MUCAPE /AOA 500 J PER KG/ SHOULD
REMAIN PRESENT TO SUPPORT A CONTINUED THREAT FOR ISOLATED
HAIL...UNTIL MORE NEARLY SFC-BASED STORMS INCREASE IN
COVERAGE/STRENGTH FARTHER TO THE E A BIT LATER IN THE DAY.
STRONG...UNIDIRECTIONAL SLY CLOUD-LAYER FLOW SHOULD ORGANIZE THE
STORMS INTO N-S BACK-BUILDING BANDS. THESE STRUCTURES COULD YIELD A
FEW CORRIDORS OF HEAVY RAIN IN AREAS AT OR CLOSE TO FREEZING.
..NE TX INTO SE OK/AR...
STORMS IN NRN SEGMENT OF FRONTAL SQLN...N OF DIFFUSE MARITIME
FRONT...COULD YIELD LARGE HAIL AND STG GUSTS AS THEY MOVE NNE WITHIN
SLIGHTLY ELEVATED PLUME OF FAVORABLE BUOYANCY/MOISTURE OVER SE
OK...SRN/CNTRL AR...NRN LA AND EXTREME NE TX. ALTHOUGH LAPSE RATES
ALOFT MAY BE WEAKER THAN FARTHER SW...RICH MOISTURE SHOULD
SUPPORT MUCAPE UP TO 1000 J/KG...WITH 45-55 KT CLOUD-LAYER SHEAR AS
EJECTING UPR SYSTEM ASSUMES AN INCREASINGLY NEGATIVE TILT.
..LA/WRN MS THIS MORNING...
A FEW SLIGHTLY ELEVATED SUSTAINED STORMS/SUPERCELLS MAY PERSIST
THROUGH THIS MORNING OVER CNTRL/NRN LA AND SW MS...IN WAA ZONE NE OF
MARITIME FRONT. THIS ACTIVITY MAY POSE A THREAT FOR LOCALLY
DAMAGING WIND BUT SHOULD GRADUALLY WEAKEN AND SHIFT NWD AS HEIGHTS
CONTINUE TO RISE DOWNSTREAM FROM APPROACHING UPR LOW. SEE UPCOMING
MCD FOR MORE DETAILS.
.CORFIDI.. 02/16/2008
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