SPC DAY-1 CONVECTIVE OUTLOOK

08 Mar 1999 - 16:27:01 UTC 
disclaimer  "for information regarding the availability and timeliness of 
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ZCZC MKCSWODY1 000
ACUS1 KMKC 081627
MKC AC 081627

CONVECTIVE OUTLOOK...REF AFOS NMCGPH94O.

VALID 081630Z - 091200Z

REF WW NUMBER 0075...VALID TIL 0180Z

THERE IS A HIGH RISK OF SVR TSTMS THIS AFTERNOON THROUGH TONIGHT
OVER PORTIONS OF LA..E TX...SRN AR..AND WRN MS. THIS AREA LIES TO
THE RIGHT OF A LINE FROM 35 S PBF 30 WNW JAN MCB 25 SW BTR LCH 50
SSW LFK 35 E TPL 35 NW TYR 35 NW TXK 45 ENE TXK 35 S PBF.

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM
35 SW GLS 55 SE AUS 55 WNW AUS 15 ESE FTW 25 S MLC 25 ENE MKO
25 WSW UNO 25 SE P02 15 NNE MKL HSV ANB TOI 20 ENE PNS.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM BLI SEA PDX MFR
60 NW UKI.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 40 ESE PSX
10 ENE VCT 15 ENE SAT 30 ESE JCT 10 W FTW 35 NW ADM 60 W CSM
35 SSE GCK 25 N JLN 35 SSE IRK LUK 10 SE HTS AHN AQQ.

SRN STREAM SHORTWAVE TROUGH NOW OVER W TX EXPECTED TO CONTINUE ENE
ACROSS THE SRN PLAINS/LOWER MS VALLEY DURING THE NEXT 24 HRS. 
ASSOCIATED BAND OF 75 KT WLY FLOW WILL SPREAD ACROSS E TX AND LA
TODAY BEFORE WEAKENING SOMEWHAT AND CONTINUING E INTO THE SRN
APPALACHIANS. AT THE SURFACE...SHALLOW NW/SE-ORIENTED WARM FRONT
NOW OVER E TX EXPECTED TO LIFT NE ACROSS LA LATER TODAY...AND INTO
SRN MS/COASTAL AL LATE TONIGHT/EARLY TUESDAY. GREATER NEWD MOTION
OF THIS BOUNDARY WILL LIKELY BE LIMITED BY CONTINUING PRESENCE OF
ISALLOBARIC BOUNDARY LAYER ELY FLOW OUT OF E COAST RIDGE.

SQUALL LINE NOW OVER CNTRL/N TX SHOULD CONTINUE E THROUGH THE
PERIOD. THE LINE SHOULD INTENSIFY LATER TODAY AND THIS EVENING
OVER PARTS OF E TX/LA AND SRN AR AS SURFACE HEATING FURTHER
DESTABLIZES INFLOW REGION AND APPROACH OF SHORTWAVE TROUGH AXIS  
ENHANCES LARGE SCALE ASCENT/VERTICAL SHEAR.  

IN THE W...UPSTREAM TROUGH OFF THE ORE/NRN CA SHOULD CONTINUE
SEWD...REACHING NRN/CNTRL CA BY 12Z TUESDAY.         

...E TX INTO LA/SRN AR/SRN MS...
RAOB GAP OVER CENTRAL AND MID COASTAL TX IS BOTHERSOME...BUT
AVAILABLE CONVENTIONAL...RADAR AND SATELLITE DATA SHOW CONTINUING
PRESENCE OF SUBSTANIAL CAP OVER SRN AND ERN TX. DESPITE THE
CAP...COMBINATION OF MODERATE SURFACE HEATING...INCREASING LARGE
SCALE UVV AND FORCED ASCENT ALONG SQUALL LINE COLD POOL LIKELY TO
RESULT IN CONTINUED STORM INITIATION ALONG AND PERHAPS JUST AHEAD OF 
CONVECTIVE LINE. CAPE NOT LIKELY TO BE EXCESSIVE...RANGING FROM
AROUND 1000 J/KG IN NE TX/LA TO AROUND 2000 J/KG OVER SE TX...BUT
WILL BE MORE THAN AMPLE TO SUPPORT DEEP CONVECTION. GIVEN THE
STRENGTH OF SHEAR /50-60 KT SLY LOW-LEVEL JET VEERING TO WSW FLOW
IN EXCESS OF 70 KTS AT 500 MB/...STRONG POTENTIAL WILL EXIST FOR
STORM ROTATION.  THUS...SQUALL LINE WILL LIKELY BECOME MORE
CELLULAR WITH TIME. ASSOCIATED LEWPS AND BOWS WILL MAINTAIN
POTENTIAL FOR A FEW LONG-LIVED TORNADOES...IN ADDITION TO DAMAGING
WINDS AND HAIL.

FARTHER E...OTHER STORMS MIGHT INITIATE INVOF SHALLOW WARM FRONT
OVER PARTS OF LA/SRN MS AND SRN AR LATER TODAY THROUGH TONIGHT. 
TORNADIC POTENTIAL WILL BE QUITE HIGH IN THIS ENVIRONMENT GIVEN
BACKED LOW-LEVEL FLOW ALONG BOUNDARY.     

TO THE NORTH AND E OF SURFACE-BASED CONVECTION...ELEVATED STORMS
WITH HAIL AND PERHAPS DAMAGING WINDS WILL LIKELY AFFECT PARTS OF
CNTRL/NRN AR...CNTRL AND NRN MS AND THE LOWER TN VALLEY AS BAND OF
STRONGEST LARGE SCALE FORCING OVERSPREADS REGION LATER
TODAY/TONIGHT.

..CORFIDI.. 03/08/99

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