Severe Thunderstorm Warning 10, NWS Brownsville, TX

DEEP SOUTH TEXAS FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
225 PM CDT FRI MAY 17 2002

CORRECTED SKY CONDITIONS IN PRELIM NUMBERS SECTION

DAYS1-3...SHORT WAVE EXITING NE MEXICO OVERNIGHT MOVED ACROSS SOUTH
TEXAS GENERATING AN MCS WHICH BRUSHED NRN EDGE OF CWFA AND IS NOW
MOVING INTO SW LA. ANOTHER MCS CROSSED FROM THE OK PANHANDLE INTO NE
TX. THIS MCS IS AHEAD OF THE COOL FRONT WHICH NOW EXTENDS FROM CNTRL
OK SW TO THE BIG BEND AREA. AT NOON TIME...OUTFLOW LEFT BY
MCS...WHICH IS NOW INTO SW LA...CAN BE SEEN ON VISIBLE SAT IMAGERY
AS ABSENCE OF CLOUDS OVER SOUTH TEXAS NORTH OF DPSOTEX. LEADING EDGE
OF OUTFLOW BOUNDARY EXTENDS FROM SINTON TO ENCINAL TO JUST EAST OF
EAGLE PASS...BUT NO SIGN OF CONVECTION PROBABLY DUE TO SUBSIDENCE IN
NW FLOW UPSTREAM OF SHORT WAVE. OVER SOUTH EAST TX...LOOKS LIKE THE
SHORT WAVE HAS BEGUN TO TAP THETA-E RIDGE OVER COASTAL PLAINS AND NW
GULF...TRIGGERING NEW CONVECTION BETWEEN VICTORIA AND HOUSTON. RUC40
AT 15Z GENERATES SOME PRE-FRONTAL CONVECTION OVER COASTAL COUNTIES
OF FA BEFORE SHORT WAVE MOVES OFFSHORE DURING THE REMAINDER OF THE
AFTERNOON. BY THIS EVENING...SURFACE LOW OVER NE MEX AND THE COOL
FRONT OVER THE HILL COUNTRY PROVIDE ENOUGH LOW LEVEL FORCING TO KICK
OFF MORE CONVECTION BETWEEN LAREDO AND DEL RIO. THE 17/12Z AVN RUN
HAS A 1.52 PWAT BULLSEYE OVER NRN HALF OF SOUTH CENTRAL
TX...INCLUDING THE HILL COUNTRY...AND MOVES THIS AREA OF RAFL RIGHT
DOWN THE PIPE OVER THE LRGV BY 7 PM SAT. EITHER WAY...LOOKS LIKE
GOOD CHANCE FOR RAIN...SO WILL LEAVE POPS AS THEY ARE. NOTE THAT NW
FRINGE OF CWFA IS BACK IN AREA OF SLGT RISK FOR SVR TSTMS THROUGH
12Z SAT...AND IN AREA OF GENERAL TSTM ACTIVITY THROUGH SAT NIGHT.
AFTER FRONTAL PASSAGE TOMORROW...HIGH PRESSURE SETS IN AT THE
SURFACE WITH UPPER LEVEL RIDGING ON SUNDAY. THE SYSTEM MOVES EAST
GRADUALLY THROUGH TUE...AHEAD OF THE NEXT SHORT WAVE CROSSING THE CA
COAST AND RIDING UP THE RIDGE INTO THE NRN PLAINS BY EARLY WED.

DAYS 4-7...AREA WINDS SHOULD VEER TO SE MON NIGHT...IN RESPONSE TO
LEE SIDE TROUGHING TRIGGERED BY NEGATIVELY-TILTED TROUGH CROSSING
THE CNTRL ROCKIES. WED LOOKS BREEZY...AS PGF TIGHTENS DUE TO SURFACE
TROUGH EXTENDING FROM NE MEX INTO THE NRN PLAINS. BY THU...SURFACE
LOW LIFTS OUT OF MONTANA ACROSS THE BORDER INTO ONTARIO AS NEXT
SHORT WAVE COMES ASHORE OVER SOCAL AND BAJA. LEE SIDE TROUGHING
AHEAD OF THIS SHORT WAVE WILL BRING RAIN FROM THE SOUTH PLAINS OF
TEXAS NORTHEAST INTO THE UPPER MS VALLEY. NEXT WEEK LOOKS LIKE LATE
NIGHT/EARLY MORNING CLOUDINESS WITH SUNNY AFTERNOONS. MIN TEMPS NEAR
NORMAL WITH MAX TEMPS SLIGHTLY ABOVE NORMAL EARLY TO ABOVE NORMAL
LATE IN THE WEEK.

MARINE...SEAS 5 FEET OFFSHORE WITH SOUTH WINDS 15 TO 20 KNOTS.
PRESSURE GRADIENT WILL RELAX AS THE FRONTAL BOUNDARY OVER NORTH TX
MOVES SOUTHWARD TONIGHT. WILL CONTINUE SCEC OFFSHORE FOR NOW AND
LIKELY DROP SCA FOR THE BAY WATERS. SCA LIKELY NEEDED BY MORNING AS
THE FRONT MOVES OFFSHORE THE LOWER TEXAS COAST BEFORE SUNRISE. WIND
AND SEAS SHOULD SUBSIDE BY SUNDAY NIGHT AS A HIGH PRESSURE RIDGE
OVER THE CENTRAL PLAINS SETTLES INTO THE SOUTHEAST U.S. SCATTERED
CONVECTION EXPECTED TO DEVELOP ALONG AND AHEAD OF THE FRONT AS IT
MOVES ACROSS THE COASTAL WATERS LATE TONIGHT INTO SAT MORNING. WINDS
WILL VEER TO THE EAST MONDAY AND TO THE SOUTHEAST TUESDAY AS THE SFC
HIGH MOVES EASTWARD. PRESSURE GRADIENT TO INCREASE WEDNESDAY WITH
LOW PRESSURE OVER THE NORTHERN PLAINS AND THE RIDGE OVER THE EASTERN
U.S.

PRELIMINARY NUMBERS...
BRO EB 073 082/067 084/065 30/30/00/00/00
HRL EB 072 083/066 085/064 30/30/00/00/00
MFE EB 072 084/064 087/062 30/30/00/00/00
RGC EB 070 086/062 089/060 40/40/00/00/00
SPI EB 075 080/071 081/068 30/30/00/00/00

SYNOPTIC...59
MARINE-AVIATION...61

INTERNET ADDRESS...WWW.SRH.NOAA.GOV/BRO

.BRO...NONE.

TXZ248>257-181200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BROWNSVILLE TX
430 PM CDT FRI MAY 17 2002

...STRONG THUNDERSTORMS...SOME POSSIBLY SEVERE...EXPECTED TONIGHT...

SCATTERED SHOWERS AND THUNDERSTORMS...SOME POSSIBLY SEVERE...ARE
EXPECTED ACROSS DEEP SOUTH TEXAS THROUGH LATE SATURDAY MORNING.
THE AIRMASS OVER THE RIO GRANDE VALLEY IS VERY MOIST AND UNSTABLE.
AN APPROACHING FRONTAL BOUNDARY...AS WELL AS OUTFLOW BOUNDARIES FROM
EARLIER CONVECTION...WILL SERVE AS THE FOCUS FOR THE DEVELOPMENT OF
THESE STORMS. AS WE GO THROUGH THE EARLY EVENING AND LATE NIGHT
HOURS THE MAIN THREAT FROM THESE STRONG STORMS WILL BE GUSTY
WINDS...HEAVY RAINFALL...AND HAIL. ALL RESIDENTS OF DEEP SOUTH TEXAS
SHOULD BE AWARE OF THE LIKELIHOOD OF THUNDERSTORMS THIS EVENING
THROUGH SATURDAY MORNING. CONTINUE TO MONITOR LOCAL
TELEVISION...RADIO AND CABLE OUTLETS...ALONG WITH NOAA WEATHER
RADIO...FOR ANY WARNINGS OR WEATHER STATEMENTS. PHILO

PHILO