Severe Thunderstorm Warning 55, NWS Brownsville, TX

DEEP SOUTH TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
810 PM CDT TUE AUG 12 2003

HAVE CUTBACK POPS FOR TONIGHT BASED ON 7 PM RADAR PRESENTATION.
LOOKING AT CURRENT WV/IR SAT IMAGERY...MOISTURE ASSOCIATED WITH WARM
CONVEYOR BELT SEEN STREAMING FROM BAY OF CAMPECHE TOWARD LWR MS
VALLEY WITH DRY SLOT OVER THE LONE STAR STATE AND EXTENDING OVER THE
COASTAL WATERS. H5 TROUGH AXIS LIKELY EXTENDING FROM ARKLATEX REGION
SWD ACRS DEEP SOUTH TEXAS COASTAL WATERS INTO TAMAULIPAS. HAVE
TRENDED POPS DOWN FOR THU NIGHT AS WELL...DUE TO WESTWARD
TRANSLATION OF H5 TROUGH TO THE WEST OF THE BIG BEND AREA OF TEXAS.
NO OTHER CHANGES ANTICIPATED AT UPDATE.

MARINE...AT 6 PM BUOY020 REPORTED NORTHEAST WINDS AT 12 KNOTS WITH
SEAS 3 FOOT. HAVE REDUCED POPS OVER BAY AND COASTAL WATERS FOR THIS
EVENING...SINCE NO ECHOES ON LOCAL RADAR. UPPER LEVEL LOW
PRESSURE WILL CONTINUE TO ENHANCE SCATTERED SHOWERS AND
THUNDERSTORMS ACROSS THE COASTAL WATERS THROUGH THE NEXT SEVERAL
DAYS. LIGHT TO MODERATE ONSHORE FLOW WILL PREVAIL DURING THIS TIME.
ONSHORE WINDS WILL BEGIN TO INCREASE THURSDAY IN RESPONSE TO A
TROPICAL WAVE MOVING WESTWARD ACROSS FLORIDA INTO THE EASTERN GULF.
THIS WAVE WILL BRING ANOTHER SIGNIFICANT AMOUNT OF PRECIPITATION TO
THE WATERS FRIDAY THROUGH THE WEEKEND.

AVIATION...AT 7 PM AUTOMATED OBSERVATIONS INDICATED VFR CONDITIONS
AT AREA AERODROMES WITH MODERATE SEABREEZE IN PLACE. EVENING TSRA
ACTIVITY APPEARS TO BE FOCUSED OVER ZAPATA AND STARR COUNTIES WHERE
OUTFLOW FROM STORMS OVER NUEVO LEON IS CONVERGING WITH SEABREEZE.
WINDS WILL BECOME LIGHT AND VARIABLE AFTER MIDNIGHT...WITH A CHANCE
OF NOCTURNAL SHOWERS AND THUNDERSTORMS DUE TO INSTABILITY GENERATED
BY UPPER LEVEL LOW SLIDING TO THE SOUTHWEST OVER THE
CHIHUAHUA/EDWARDS PLATEAU REGION BY WED EVENING. THIS LOW WILL ONCE
AGAIN ENHANCE SEABREEZE/CONVECTIVE SHOWERS AND THUNDERSTORMS ON
TOMORROW...SOME POSSIBLY SEVERE.

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE         BC 075/088 075/088 075 30/60/60/60/30
HARLINGEN           BC 074/089 074/089 074 30/60/60/60/30
MCALLEN             BC 075/090 075/090 075 40/60/60/60/30
RIO GRANDE CITY     BC 074 090 074/090 074 40/60/60/60/30
SOUTH PADRE ISLAND  BC 079/087 078/087 078 20/60/60/60/30

.BRO...NONE.

59/60

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

TXZ248>257-131100-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BROWNSVILLE TX
235 PM CDT TUE AUG 12 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR DEEP SOUTH TEXAS.

.DAY ONE...TODAY AND TONIGHT.

A MOIST AND UNSTABLE ATMOSPHERE...IN COMBINATION WITH A LINGERING
SEA BREEZE FRONT AND DAYTIME HEATING...WILL GENERATE SCATTERED
SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND THIS EVENING. SOME OF
THESE STORMS MAY BE SEVERE...PRODUCING WIND GUSTS IN EXCESS OF 60
MPH...HEAVY RAIN...FLOODING OF ROADWAYS...FREQUENT LIGHTNING AND
HAIL.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH SUNDAY.

AN UPPER LEVEL TROUGH WILL APPROACH FROM THE NORTHEAST ON TUESDAY
THEN MOVE WESTWARD INTO MEXICO BY THURSDAY. THIS SYSTEM WILL
DESTABILIZE THE ATMOSPHERE AND INCREASE THE CHANCES FOR SHOWERS AND
THUNDERSTORMS. SOME OF THE SHOWERS AND THUNDERSTORMS COULD PRODUCE
STRONG GUSTY WINDS AND HEAVY RAINS. SCATTERED SHOWERS AND
THUNDERSTORMS WILL TAPER TO ISOLATED COVERAGE FRIDAY AS THE UPPER
LEVEL TROUGH MOVES FARTHER WEST INTO NORTHWESTERN MEXICO AND UPPER
LEVEL HIGH PRESSURE BUILDS IN FROM THE WESTERN GULF.

.SPOTTER INFORMATION STATEMENT.

SPOTTERS AND EMERGENCY MANAGERS ARE ASKED TO MONITOR WEATHER
CONDITIONS CLOSELY THIS AFTERNOON AND TONIGHT.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BROWNSVILLE, TX
352 PM CDT TUE AUG 12 2003

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0255 PM    2 E LA FERIA              TX   .75 INCH HAIL
08/12/03   CAMERON                        HAIL TO THE SIZE OE
                                          PENNIES WAS REPORTED BY A
                                          WEATHER SPOTTER.

0255 PM    2 E LA FERIA              TX   60 MPH WIND GUST
08/12/03   CAMERON                        STRONG WINDS TO 60 MPH
                                          WERE REPORTED BY A WEATHER
                                          SPOTTER IN A THUNDERSTORM.