Severe Thunderstorm Warning 1, NWS Brownsville, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
156 PM CDT FRI APR 17 2009

.DISCUSSION...SATELLITE AND RADAR IMAGES INDICATE THUNDERSTORMS
FROM MCS OVER EAST-CENTRAL TEXAS THIS AFTERNOON EXTENDING BACK
INTO THE RIO GRANDE PLAINS. WITH SKIES CLEARING ACROSS DEEP SOUTH
TX...SO FAR THE CAP CONTINUES TO HOLD AND THE STRONGER WINDS
APPEAR TO BE KEEPING A LID ON CONVECTION. LAPS SURFACE ANALYSIS
INDICATED THE STRONGEST LIFTING INDICIES ACROSS WESTERN PORTIONS
OF THE CWA AS WELL AS WHERE THE HIGHEST CAPES RESIDE. WOULD NOT BE
SURPRISED TO SEE THUNDERSTORMS DEVELOP EAST OF THE SURFACE THETA-E
RIDGE ACROSS NORTHWEST PORTIONS OF THE CWA LATE AFTERNOON INTO
EARLY EVENING MAINLY ALONG OUTFLOW FROM CONVECTION NEAR COTULLA.
WITH THAT SAID...WILL KEEP A SLIGHT CHANCE OF THUNDERSTORMS NORTH
FOR THIS EVENING AND WILL INCREASE POPS NORTHWEST TONIGHT AS THE
NAM12 PROGS CONVECTION DEVELOPING ACROSS SOUTHWEST TX PROPAGATING
INTO DEEP SOUTH TX SATURDAY MORNING. IN ADDITION...SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE CONVECTIVE
BOUNDARY OVER EAST TX EXTENDING SOUTHWARD TOWARDS THE COASTAL BEND
AND THE RIO GRANDE PLAINS. WILL GO AHEAD AND INCREASE POPS FROM
SOUTH TO NORTH WITH THE BEST RAIN CHANCES ACROSS THE NORTHERN
PORTIONS OF THE CWA. EVEN THOUGH THE AREA REMAINS OUTSIDE OF THE
SLIGHT RISK AREA FOR SEVERE WEATHER...POTENTIAL EXISTS FOR STRONG
TO SEVERE STORMS WITH POSSIBLY DAMAGING WINDS AND HAIL AND WITH
ABUNDANT LOW LEVEL MOISTURE ACROSS THE LOWER RIO GRANDE
VALLEY...STORMS COULD PRODUCE HEAVY RAINFALL ESPECIALLY WITH SLOW
MOVING ONES. RAIN CHANCES WILL LINGER SAT NIGHT INTO EARLY SUNDAY
BEFORE A WEAK COLD FRONT BRINGS DRIER AIR INTO THE AREA. HIGH
PRESSURE WILL BUILD INTO SOUTH TX MONDAY INTO TUESDAY BEFORE
SHIFTING EASTWARD WEDNESDAY ALLOWING RETURN FLOW TO DEVELOP
TOWARDS THE MIDDLE OF THE WEEK. MODERATE SOUTHEAST FLOW SHOULD
PREVAIL THROUGH THE REST OF THE PERIOD.
&&

.AVIATION...MVFR TO VFR CIG WILL PREVAIL OVER THE REGIONAL AIRPORTS
THROUGH TONIGHT BECOMING VFR BY MID MORNING ON SATURDAY. WINDS WILL
BE MODERATE FROM THE SOUTHEAST FOR THE NEXT 24 HOURS.
&&

.MARINE...BOY020 REPORTED WINDS FROM THE SOUTHEAST AT 15 KNOTS
GUSTING TO 22 KNOTS WITH SEAS NEAR 10 FEET. SMALL CRAFT ADVISORIES
WILL CONTINUE TODAY AS THE PRESSURE GRADIENT CONTINUES TIGHT. A LOW
PRESSURE SYSTEM OVER NORTHERN TEXAS AND HIGH PRESSURE OVER THE GULF
OF MEXICO WILL HELP MAINTAIN A MODERATE TO STRONG SOUTHEAST FLOW OF
AIR. A COLD FRONT WILL MOVE THROUGH DEEP SOUTH TEXAS COASTAL WATERS
ON SUNDAY CAUSING A STRONG NORTH WIND IN ITS WAKE.  SOME ISOLATED TO
SCATTERED SHOWERS OR THUNDERSTORMS ARE POSSIBLE TODAY THROUGH SUNDAY
WITH CONSIDERABLE AMOUNT OF MOISTURE AVAILABLE.  A DRIER AIRMASS
WILL BE IN STORE FOR THE COASTAL WATERS THE BEGINNING OF NEXT WEEK.
&&

.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL  75  85  70  88 /  20  30  20  30
BROWNSVILLE          76  86  71  89 /  20  40  20  30
HARLINGEN            72  85  68  90 /  20  40  20  30
MCALLEN              73  87  70  92 /  20  40  20  10
RIO GRANDE CITY      74  81  71  93 /  20  40  10  10
SOUTH PADRE ISLAND   76  83  71  84 /  20  30  20  30
&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR GMZ130-
     132-135.

     SMALL CRAFT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR GMZ150-155-
     170-175.
&&

THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WWW.WEATHER.GOV/BROWNSVILLE

PUBLIC/GRIDS...61
AVIATION/MARINE...65
MESO/FXC...MARTINEZ

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
315 PM CDT FRI APR 17 2009

GMZ130-132-135-150-155-170-175-TXZ248>257-181100-
LAGUNA MADRE FROM THE PORT OF BROWNSVILLE TO THE ARROYO COLORADO-
LAGUNA MADRE FROM THE ARROYO COLORADO TO 5 NM NORTH OF PORT
MANSFIELD TX-
LAGUNA MADRE FROM 5 NM NORTH OF PORT MANSFIELD TO BAFFIN BAY TX-
COASTAL WATERS FROM PORT MANSFIELD TO THE RIO GRANDE OUT 20 NM-
COASTAL WATERS FROM BAFFIN BAY TO PORT MANSFIELD OUT 20 NM-
WATERS FROM PORT MANSFIELD TO THE RIO GRANDE EXTENDING FROM 20 TO
60 NM-
WATERS FROM BAFFIN BAY TO PORT MANSFIELD EXTENDING FROM 20 TO
60 NM-ZAPATA-JIM HOGG-BROOKS-KENEDY-STARR-HIDALGO-INLAND WILLACY-
INLAND CAMERON-COASTAL WILLACY-COASTAL CAMERON-
315 PM CDT FRI APR 17 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR DEEP SOUTH TEXAS...THE GULF
OF MEXICO AND THE LAGUNA MADRE.

.DAY ONE...TONIGHT.

A SMALL CRAFT ADVISORY IS IN EFFECT FOR THE GULF OF MEXICO WATERS
EAST OF PADRE ISLAND DUE TO LARGE EASTERLY SWELLS. THERE IS A HIGH
RISK OF RIP CURRENTS AT THE BEACHES OF SOUTH PADRE ISLAND AND BOCA
CHICA DUE TO THESE SWELLS.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

THE SMALL CRAFT ADVISORY ALONG THE LOWER TEXAS COAST MAY NEED TO BE
EXTENDED THROUGH SUNDAY NIGHT OR MONDAY DUE TO PERSISTENT EASTERLY
SWELLS AND THE PASSAGE OF A COLD FRONT. A MODERATE TO HIGH RISK OF
RIP CURRENTS AT THE LOCAL BEACHES WILL LIKELY ACCOMPANY THE ADVERSE
MARINE CONDITIONS. SCATTERED THUNDERSTORMS ARE ANTICIPATED SATURDAY.
ANY OF THE STRONGER THUNDERSTORMS WILL HAVE THE POTENTIAL TO PRODUCE
HAIL AND DAMAGING WINDS.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTER ACTIVATION WILL NOT BE NEEDED.

TOMASELLI