Severe Thunderstorm Warning 34, NWS Brownsville, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
350 AM CDT SAT MAY 1 2004

.SHORT TERM...SATELLITE IMAGES INDICATE ELEVATED CONVECTION
CONTINUES TO DEVELOP ACROSS PORTIONS OF NORTHEAST AND SOUTHWEST
TEXAS THIS MORNING. RELATIVELY STRONG COLD FRONT CONTINUES TO MOVE
INTO CENTRAL TX WITH MOIST AND UNSTABLE AIRMASS ACROSS SOUTH TX.
LAPS SURFACE ANALYSIS INDICATES CAPES OF 2500 J/KG ACROSS THE CWA
WITH LIFTING INDEX OF NEAR -7. IN ADDITION...VAD WIND PROFILE
INDICATES 50 KNOT LOW LEVEL JET ADVECTING MOISTURE NORTHWARD INTO
CONVECTIVE COMPLEXES TO THE NORTH. WITH THE 500MB TROUGH MOVING INTO
WEST TX LAPSE RATES WILL STEEPEN AS THE COLD FRONT MOVES INTO SOUTH
TX THIS MORNING AND DEEP SOUTH TX LATER THIS AFTERNOON PROVIDING A
FOCUS FOR LOW LEVEL CONVERGENCE. UPPER LEVEL DIFFLUENCE IN
COMBINATION WITH RIGHT REAR QUADRANT OF 200MB JET STREAM WILL
PROVIDE FAVORABLE ENVIRONMENT FOR SEVERE WEATHER TO DEVELOP THIS
AFTERNOON. 00Z ETA SOUNDINGS PROGS DEEP DIRECTIONAL SHEAR DEVELOPING
AS WELL AND ONLY LIMITING FACTOR SO FAR IS STRONG CAP AT 900MB.
LATEST SPC OUTLOOK HAS SOUTH TX IN SLIGHT RISK WITH GREATEST THREAT
BEING HAIL AND DAMAGING WINDS BUT WOULD NOT RULE OUT AN ISOLATED
TORNADO WITH ISOLATED CONVECTION DEVELOPING AHEAD OF THE MAIN LINE
OF SHOWERS AND THUNDERSTORMS. LOCALLY HEAVY RAINFALL WILL ALSO BE A
CONSIDERATION AND A FLASH FLOOD WATCH MAY BE NEEDED THIS AFTERNOON.
WILL INCREASE POPS TODAY WITH SEVERE THUNDERSTORMS AND HEAVY
RAINFALL POSSIBLE IN ZONES/GRIDS THIS AFTERNOON INTO EVENING. WILL
ISSUE SPS TO ADDRESS LOCALLY HEAVY RAINFALL FOR NOW. RAIN CHANCES
SHOULD DIMINISH TONIGHT AS THE FRONT MOVES THROUGH THE LOWER RIO
GRANDE VALLEY AND THE 500MB TROUGH MOVES EASTWARD. CLEARING TREND TO
CONTINUE INTO SUNDAY WITH HIGH PRESSURE BRINGING DRIER AND COOLER
AIR INTO TEXAS AND NORTHWEST FLOW ALOFT PROVIDING SUBSIDENCE. LOW
TEMPERATURES SUNDAY NIGHT MAY BE COOLER THAN EXPECTED WITH
RADIATIONAL COOLING BUT WILL GO WARMER THAN MAV TEMPERATURE GUIDANCE.
&&

.LONG TERM...TEMPERATURES TO GRADUALLY WARM THROUGH THURSDAY WITH
HIGH PRESSURE OVER SOUTH TX MONDAY SHIFTING EASTWARD TUESDAY AND
RETURN FLOW DEVELOP WEDNESDAY. MOISTURE WILL INCREASE THURSDAY INTO
FRIDAY AS THE 00Z GFS PROGS A 500MB LOW DEVELOPING ACROSS TX FRIDAY.
WILL KEEP MENTION OF SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS
FRIDAY.
&&

.MARINE...AT 1AM BUOY020 REPORTED SOUTHEAST WINDS AT 10KTS AND 3
FOOT SEAS. THE COLD FRONT IS CURRENTLY MOVING THROUGH THE TEXAS HILL
COUNTRY. IT WILL ARRIVE IN THE COASTAL WATERS ZONES SATURDAY
EVENING. STRONG THUNDERSTORMS ARE EXPECTED ALONG AND AHEAD OF THE
FRONT WITH STRONG GUSTY WINDS...FREQUENT LIGHTNING AND HEAVY
DOWNPOURS. AROUND THIS TIME TOMORROW...NORTHERLY WINDS WILL RACE IN
AT 20 TO 25 KNOTS BRINGING UP SEAS TO 8 TO 10 FEET FOR SATURDAY
NIGHT AND SUNDAY. SMALL CRAFT ADVISORIES ARE LIKELY IN THE WAKE OF
THE FRONT. HIGH PRESSURE BUILDING INTO THE REGION TUESDAY WILL RELAX
WINDS AND SEAS BEFORE TURNING BACK TO THE SOUTHEAST MIDWEEK. &&

.AVIATION...SFC WINDS AT LOCAL STATIONS ARE BELOW 10KTS BUT BRO VWP
SHOWS WINDS FROM THE SOUTH AT 35KTS AT 1KFT AND 50KTS AT 5KFT. LLVL
CLOUD DECK BTWN 800 AND 1200FT BEING MIXED WELL BY LOW LEVEL JET.
MIXING EFFECT MAY BE COUNTERED BY MOISTURE FOCUSING AHEAD OF THE
COLD FRONT TO THE NORTH. VIS SHOULD STAY ABOVE 3SM. WINDS WILL AGAIN
INCREASE TOMORROW MORNING AS THE LOW LEVEL JET BEGINS TO MIX TOWARD
THE SURFACE. THUNDERSTORMS DEVELOP TOMORROW AFTERNOON AS THE FRONT
MOVES INTO DEEP SOUTH TEXAS. THE MAIN CONCERN WITH THE STORMS WILL
BE STRONG GUSTY WINDS. WINDS BEHIND THE FRONT WILL TURN TO THE
NORTHEAST AND BE BRIEFLY GUSTY.
&&

.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL  81 62 76 61 79/ 70 60 00 00 00
BROWNSVILLE          83 61 78 60 81/ 70 60 00 00 00
HARLINGEN            83 60 78 59 81/ 70 60 00 00 00
MCALLEN              82 59 78 58 82/ 70 40 00 00 00
RIO GRANDE CITY      81 57 77 56 82/ 60 30 00 00 00
SOUTH PADRE ISLAND   80 63 75 62 77/ 70 60 00 00 00
&&

.BRO WATCHES/WARNINGS/ADVISORIES...NONE.
&&

SYNOPTIC/GRIDS...61
MARINE/AVIATION/MESO...64

THIS PRODUCT IS ALSO AVAILABLE ON OUR INTERNET WEB PAGE AT:
HTTP://WWW.SRH.NOAA.GOV/BRO

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BROWNSVILLE TX
600 AM CDT SAT MAY 1 2004

TXZ248>257-021100-
BROOKS-COASTAL CAMERON-COASTAL WILLACY-HIDALGO-INLAND CAMERON-
INLAND WILLACY-JIM HOGG-KENEDY-STARR-ZAPATA-
600 AM CDT SAT MAY 1 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR DEEP SOUTH TEXAS.

.DAY ONE...TODAY AND TONIGHT.

A LATE SEASON COLD FRONT WILL MOVE THROUGH DEEP SOUTH TEXAS TODAY.
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
DEVELOP DURING THE LATTER HALF OF THE DAY. THERE IS THE POTENTIAL
FOR SEVERE THUNDERSTORMS...WITH GUSTY WINDS...FREQUENT LIGHTNING AND
LOCALLY HEAVY RAINFALL AS THE FRONT APPROACHES. PLEASE STAY TUNED TO
NOAA WEATHER RADIO FOR UPDATES THROUGHOUT THE DAY.

AFTER THE FRONT PASSES...GUSTY NORTH WINDS WILL RACE ACROSS THE
COASTAL WATERS INCREASING SEAS TO NEAR 10 FEET. SMALL CRAFT
ADVISORIES WILL BE IN EFFECT FOR SATURDAY NIGHT AND SUNDAY.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

SMALL CRAFT ADVISORIES WILL CONTINUE THROUGH SUNDAY BEFORE WEAKENING
ON MONDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED ON SATURDAY.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BROWNSVILLE TX
508 AM CDT SAT MAY 1 2004

TXZ248>257-011400-
BROOKS-COASTAL CAMERON-COASTAL WILLACY-HIDALGO-INLAND CAMERON-
INLAND WILLACY-JIM HOGG-KENEDY-STARR-ZAPATA-
508 AM CDT SAT MAY 1 2004

...STRONG COLD FRONT WITH SHOWERS AND THUNDERSTORMS WILL MOVE INTO
DEEP SOUTH TEXAS THIS AFTERNOON...

A RELATIVELY STRONG COLD FRONT OVER CENTRAL TEXAS THIS MORNING WILL
MOVE INTO DEEP SOUTH TEXAS THIS AFTERNOON. SHOWERS AND THUNDERSTORMS
ARE EXPECTED TO DEVELOP OVER THE RIO GRANDE PLAINS THIS MORNING AND
MOVE INTO NORTHERN PORTIONS OF DEEP SOUTH TEXAS THIS AFTERNOON. AS
THE COLD FRONT MOVES INTO THE LOWER RIO GRANDE VALLEY THIS
AFTERNOON...SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP AS THE
FRONT COLLIDES WITH A VERY MOIST AND UNSTABLE ATMOSPHERE.

RAINFALL AMOUNTS OF HALF AN INCH TO ONE INCH ARE LIKELY WITH ISOLATED
AMOUNTS OF 1 TO 2 INCHES POSSIBLE. GIVEN THE RECENT RAINS AND THE
SATURATED GROUNDS ACROSS DEEP SOUTH TEXAS...AREAS RECEIVING
ADDITIONAL HEAVY RAINFALL MAY EXPERIENCE LOCAL FLOODING. A FLASH
FLOOD WATCH MAY BE ISSUED LATER THIS MORNING FOR DEEP SOUTH TEXAS AS
THE FRONT MOVES CLOSER TO THE AREA.

CASTILLO

TXZ248-249-011415-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BROWNSVILLE TX
828 AM CDT SAT MAY 1 2004

...COLD FRONT WITH THUNDERSTORMS HEADED FOR ZAPATA AND JIM HOGG
COUNTIES...

A COLD FRONT OVER SOUTH CENTRAL TEXAS WAS SOUTHEAST AT 35 TO 40
MPH. THUNDERSTORMS ALONG THE FRONT WILL BE INVADING ZAPATA COUNTY
WITHIN THE NEXT HALF HOUR. THIS LINE OF THUNDERSTORMS MAY REACH JIM
HOGG COUNTY BY 9 AM.

RESIDENTS OF ZAPATA AND JIM HOGG COUNTIES SHOULD EXPECT VERY HEAVY
RAIN...FREQUENT DANGEROUS LIGHTNING AND GUSTY WINDS DURING THE NEXT
HOUR. ADDITIONALLY...DEEP SOUTH TEXAS IS WITHIN AN AREA DESIGNATED
AS HAVING A SLIGHT RISK OF SEVERE THUNDERSTORMS THROUGH 7 AM SUNDAY.
THEREFORE...PEOPLE WITHIN THESE TWO COUNTIES SHOULD BE ALERT FOR
RAPIDLY CHANGING WEATHER CONDITIONS.

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