Flash Flood Warning 17, NWS Brownsville, TX

000 
WGUS74 KBRO 121224
FFSBRO
TXC427-121330-

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE BROWNSVILLE TX
723 AM CDT FRI SEP 12 2003

...FLASH FLOOD WARNING CONTINUES UNTIL 830 AM CDT FOR STARR COUNTY...

AT 718 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS STARR COUNTY. DOPPLER 
RADAR ESTIMATED RAINFALL RATES OF TWO AND A HALF INCHES PER HOUR IN 
CENTRAL STARR COUNTY.

SLOW MOVING THUNDERSTORMS ARE PRODUCING VERY HEAVY RAINFALL IN STARR 
COUNTY. RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLOODING TO 
OCCUR...ESPECIALLY ALONG SMALL STREAMS AND NEAR LOW WATER CROSSINGS. 
SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...FALCON 
DAM...EL SAUZ...ROMA...RIO GRANDE CITY...LA GLORIA AND GARCIASVILLE.

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLOODING OF SMALL CREEKS 
AND STREAMS...COUNTRY ROADS...NORMALLY DRY WASHES AND ARROYOS...AS 
WELL AS FARMLAND ALONG THE BANKS OF CREEKS AND STREAMS.

LAT...LON 2679 9836 2625 9861 2636 9891 2642 9907
          2657 9918 2666 9901 2679 9897

$$

54

DEEP SOUTH TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
345 AM CDT FRI SEP 12 2003

SHORT TERM...SATELLITE AND RADAR IMAGES INDICATE A BAND OF SHOWERS
AND THUNDERSTORMS MOVING ACROSS THE RIO GRANDE PLAINS TOWARDS THE
CWA THIS MORNING. HEAVY RAINFALL APPEARS THE GREATEST THREAT FROM
THIS CONVECTION WITH MOIST AND UNSTABLE AIRMASS ACROSS THE LOWER RIO
GRANDE VALLEY. WITH 500MB TROUGH OVER NORTHWEST TEXAS
TODAY...CONVECTION SHOULD CONTINUE TO DEVELOP WHERE OUTFLOW BOUNDARY
COLLIDES WITH ABUNDANT MOISTURE OVER SOUTH TX. CONVECTIVE BOUNDARY
PROGGED TO MOVE THROUGH DEEP SOUTH TX TONIGHT. WILL HOLD OFF ON
FLASH FLOOD WATCH ATTM BUT WILL WORD ZONES WITH LOCALLY HEAVY
RAINFALL POSSIBLE TODAY AND TONIGHT FOR NOW. WILL HAVE TO SEE HOW
MUCH RAINFALL FALLS ACROSS THE AREA AND ASSESS THE POTENTIAL OF
SHOWERS AND THUNDERSTORMS REDEVELOPING THIS AFTERNOON AND TONIGHT.

.MARINE...WILL MAINTAIN THE SCA FOR THE OFFSHORE WATERS AS A SQUALL
LINE IS PROGGED TO MOVE THROUGH BY MIDMORNING. THE MAIN THREAT WILL
BE THE STRONG GUSTY WINDS...LIGHTNING AND BRIEF HEAVY DOWNPOURS.
SEAS ARE BELOW 7 FEET AND WILL NOT HAVE AN OPPORTUNITY TO
SIGNIFICANTLY RESPOND TO THE WINDS. SCATTERED SHOWERS WILL CONTINUE
OVER THE COASTAL WATERS INTO THE WEEKEND WITH IMPROVING CONDITIONS
AFTER THAT.

.AVIATION...THE MAIN CONCERN TODAY WILL BE A SQUALL LINE EXPECTED TO
MOVE THROUGH NEAR DAYBREAK OR EARLY MORNING. IFR CONDITIONS WILL BE
POSSIBLE IN AND NEAR STRONG THUNDERSTORMS ASSOCIATED WITH THE SQUALL
LINE. AREAS OF CONTINUED CONVECTION AND RAINFALL MAY IMPACT THE BRO
AIRPORT WITH MVFR CONDITIONS THROUGH EARLY SATURDAY.

EXTENDED...MODELS CONTINUE TO DIVERGE SATURDAY AS THE SHORTWAVE
TROUGH OVER NORTH TX LIFTS NORTHEAST. THE WEAK FRONTAL BOUNDARY OVER
CENTRAL TX WASHES OUT ACCORDING TO THE ETA WITH SOUTHEAST WINDS
PREVAILING THROUGH SUNDAY. THE GFS BRINGS A SECONDARY BOUNDARY INTO
SOUTH TX SAT NIGHT WITH WINDS BACKING TO THE EAST AND NORTHEAST
SUNDAY. ALSO THE GFS PROGS ADDITIONAL CONVECTION DEVELOPING ACROSS
THE LOWER RIO GRANDE VALLEY. WILL LEAN TOWARDS THE ETA SOLN FOR NOW
BUT WILL HAVE TO BLEND THE GFS SOLN WITH THE ETA SUNDAY AND SCALE
BACK ON RAIN CHANCES ACCORDINGLY SUNDAY AND MONDAY. HIGH PRESSURE
SETTLING OVER THE EASTERN U.S. TUESDAY SHOULD PROVIDE AN EAST TO
SOUTHEAST FLOW THROUGH THE REST OF THE PERIOD.

.BRO WATCHES/WARNINGS/ADVISORIES...SCA FOR GMZ130-150-155-170-175.

.PRELIMINARY POINT/TEMPS/POPS...
BROWNSVILLE          EE 090/078 090/080 088 40/40/20/20/40
HARLINGEN            EE 091/077 091/079 089 40/40/20/20/40
MCALLEN              EE 092/078 092/080 090 40/40/20/20/40
RIO GRANDE CITY      EE 093/076 093/078 092 40/40/20/20/40
SOUTH PADRE ISLAND   EE 088/079 088/081 086 40/40/20/20/40

SYNOPTIC-GRIDS...CASTILLO/MARINE-AVIATION-MESO...MILLER

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

TXZ248>257-121100-

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
109 AM CDT FRI SEP 12 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR DEEP SOUTH TEXAS.

.DAY ONE...REST OF TONIGHT.

SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL ACCOMPANY A
SQUALL LINE MOVING SOUTH INTO DEEP SOUTH TEXAS EARLY FRIDAY MORNING.
HAZARDS WILL BE FREQUENT LIGHTNING...STRONG GUSTY STRAIGHT LINE
WINDS OF 35 MPH...AND LOCALLY HEAVY RAINFALL OF ONE QUARTER TO ONE
HALF AN INCH.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH THURSDAY.

LINGERING CONVECTION WILL PERSIST BUT DIMINISH THROUGH SATURDAY AND
SUNDAY. NO HAZARDOUS WEATHER IS EXPECTED AFTER SATURDAY THROUGH THE
END OF THE FORECAST PERIOD.

.SPOTTER INFORMATION STATEMENT...

EMERGENCY MANAGERS AND SPOTTERS SHOULD MONITOR THE DEVELOPING
WEATHER SITUATION TODAY. SKYWARN SPOTTER ACTIVATION MAY BE NEEDED
LATER TODAY.