DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 061952
SWODY1
SPC AC 061950

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0150 PM CST WED FEB 06 2013

VALID 062000Z - 071200Z

...NO SVR TSTM AREAS FORECAST...

...S AND SE TX AND SRN LA...
SHORTWAVE UPPER TROUGH NOW MOVING THROUGH S TX WILL CONTINUE TO MOVE
PARALLEL TO THE GULF COAST THROUGH LATE TONIGHT. DRY MIDLEVEL AIR
/EVIDENT ON WATER VAPOR IMAGERY/ IN THE WAKE OF THE SHORTWAVE HAS
OVERSPREAD S TX...COINCIDING WITH A DECREASE IN CONVECTIVE COVERAGE
NEAR AND IMMEDIATELY E OF THE LOWER RIO GRANDE VALLEY. ADDITIONAL
TSTMS MAY FORM OVER THE SERRANIA DEL BURRO MTNS OF NRN MX WITHIN A
LOW-LEVEL UPSLOPE REGIME AND MOVE EWD TOWARDS DEEP S TX LATER THIS
EVENING...BUT ANY ACCOMPANYING THREAT FOR HAIL WOULD APPEAR TO BE
VERY ISOLATED/MARGINAL. MEANWHILE...A CLUSTER OF TSTMS ALONG COASTAL
S TX IS SLOWLY SHIFTING OFFSHORE...WITH REDEVELOPMENT OF ISOLATED
TSTMS OCCURRING NEAR A W-E ORIENTED OUTFLOW BOUNDARY. THESE STORMS
COULD POSE A LOCALIZED RISK FOR HAIL/WIND AND PERHAPS A BRIEF/WEAK
TORNADO. SEE MCD 116 FOR MORE DETAILS ON THE S TX PORTION OF THE
HIGHLIGHTED AREA.

LATER TONIGHT...STRENGTHENING WAA AHEAD OF THE SHORTWAVE UPPER
TROUGH MAY SUPPORT THE DEVELOPMENT OF A WEAK SFC CYCLONE NEAR
COASTAL SE TX INTO SRN LA. ALTHOUGH BUOYANCY WILL BE QUITE
LIMITED...AND THERE IS UNCERTAINTY WHETHER SFC-BASED PARCELS CAN BE
SUSTAINED...A NON-ZERO/CONDITIONAL RISK OF A DMGG WIND
GUSTS/ISOLATED TORNADO MAY EXIST OVERNIGHT...WITH LOW-END
PROBABILITIES MAINTAINED.

..ROGERS/DIAL.. 02/06/2013

.PREV DISCUSSION... /ISSUED 1028 AM CST WED FEB 06 2013/

...S TX AND SRN LA REST OF TODAY THROUGH LATE TONIGHT...
LOW-AMPLITUDE SHORTWAVE TROUGHS CROSSING NRN MEXICO AND S TX PER
WATER VAPOR IMAGERY WILL CONTINUE TO SUPPORT EPISODIC CONVECTION
THROUGH THE REMAINDER OF THE PERIOD. ONE AREA OF SCATTERED
THUNDERSTORMS IS CURRENTLY MOVING OFF THE LOWER TX COAST. A MARGINAL
SVR THREAT MAY LINGER IN THE SHORT-TERM FROM AROUND CRP TOWARD PSX
GIVEN AROUND 50 KT OF DEEP SHEAR AND MODEST LOW-LEVEL DIRECTIONAL
SHEAR PER CRP VWP DATA...ALONG WITH AROUND 1000 J/KG OF MLCAPE PER
THE 12Z CRP RAOB.

AS THE SHORTWAVE TROUGH ASSOCIATED WITH THIS ACTIVITY CONTINUES TO
ADVANCE EWD OVER THE NWRN/N-CNTRL GULF...A STRENGTHENING SLY
LOW-LEVEL JET WILL SHIFT EWD FROM THE UPPER TX COAST TO COASTAL LA.
IN RESPONSE...CONVECTIVE COVERAGE WILL PROBABLY INCREASE OVER THE
GULF WATERS...WITH WAA ATOP A CONVECTIVELY REINFORCED COASTAL
BAROCLINIC ZONE SUPPORTING WIDESPREAD PRECIPITATION INLAND -- MAINLY
STRATIFORM IN NATURE. ACCOMPANYING THETA-E DEFICITS SHOULD PRECLUDE
ANY APPRECIABLE INLAND PENETRATION OF WARMER/MORE MOIST/UNSTABLE
MARINE TRAJECTORIES WITHIN THE SFC LAYER...LIMITING BOUNDARY-LAYER
DESTABILIZATION AND LIMITING AN INLAND SVR THREAT.

HOWEVER...LATE TONIGHT...A WEAK SFC WAVE MAY DEVELOP ALONG THE
BAROCLINIC ZONE AS WAA STRENGTHENS. DEPENDING ON THE LOCATION AND
STRENGTH OF THE WAVE -- FOR WHICH UNCERTAINTY EXTENDS FROM
ANTECEDENT CONVECTIVE TRENDS -- VERY MODEST BOUNDARY-LAYER
DESTABILIZATION COULD OCCUR OVER COASTAL SECTIONS OF S-CNTRL AND
SERN LA. A CONDITIONAL THREAT FOR A SVR WIND GUST AND POSSIBLY A
BRIEF TORNADO CANNOT BE RULED OUT...GIVEN STRONG LOW-LEVEL AND DEEP
SHEAR. REGARDLESS...THE LACK OF CONFIDENCE IN THE DEVELOPMENT OF
SFC-BASED EFFECTIVE INFLOW LAYERS OVER INLAND LOCATIONS PRECLUDES
THE INTRODUCTION OF HIGHER SVR PROBABILITIES.

ADDITIONALLY...A FEW STORMS COULD IMPACT PARTS OF S TX THIS
AFTERNOON AND EVENING IN THE WAKE OF MORNING CONVECTION...AS AN
UPSLOPE REGIME AFFECTS THE ERN SLOPES OF THE NRN MEXICO MOUNTAINS
AMIDST WEAK MID-LEVEL DCVA. AN ISOLATED SVR STORM CANNOT BE RULED
OUT WITH THIS ACTIVITY GIVEN STRONG DEEP SHEAR AND STEEP MID-LEVEL
LAPSE RATES PER FORECAST SOUNDINGS. HOWEVER...THE INFLUX OF DRIER
AIR IN THE MID-LEVELS ACROSS NRN MEXICO FROM THE E PACIFIC PER
RECENT WATER VAPOR IMAGES AND THE LACK OF STRONGER FORCING FOR
ASCENT MAY PROVE HOSTILE FOR UPDRAFT DEVELOPMENT/MAINTENANCE.

...NWRN/N-CNTRL TX AND WRN OK THIS AFTERNOON AND EVENING...
AN ISOLATED STORM OR TWO COULD DEVELOP ALONG A N/S-ORIENTED DRYLINE
THIS AFTERNOON AND PERSIST INTO THE EVENING. ISOLATED OCCURRENCES OF
GUSTY WINDS OR SMALL HAIL CANNOT BE RULED OUT. HOWEVER...FAIRLY HIGH
LFC HEIGHTS...LIMITED DEEP MOISTURE...AND THE LACK OF STRONGER
MID-LEVEL FORCING FOR ASCENT SHOULD GREATLY MITIGATE STORM
STRENGTH/PERSISTENCE/COVERAGE.

...CNTRL/ERN KS AND NRN OK LATE TONIGHT...
SCATTERED THUNDERSTORMS WILL LIKELY DEVELOP ALONG/JUST BEHIND A COLD
FRONT ADVANCING SEWD INTO MARGINAL ELEVATED INSTABILITY. SMALL HAIL
OR PERHAPS GUSTY WINDS CANNOT BE RULED OUT. HOWEVER...DOWNDRAFT
PENETRATION TO THE SFC WILL LIKELY BE MITIGATED BY STRENGTHENING
BOUNDARY-LAYER CINH OWING TO NOCTURNAL STABILIZATION AND THE
UNDERCUTTING NATURE OF THE FRONT. THE LIMITED AMOUNT OF ELEVATED
INSTABILITY SHOULD PRECLUDE ANY SVR-HAIL THREAT.

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