187
FXUS64 KBRO 131752
AFDBRO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
1252 PM CDT WED AUG 13 2025
..NEW DISCUSSION, AVIATION, MARINE
KEY MESSAGES
UPDATED AT 1252 PM CDT WED AUG 13 2025
- THERE IS A LOW CHANCE (10%) OF TROPICAL DEVELOPMENT OVER THE
BAY OF CAMPECHE THROUGH THE NEXT 48 HOURS.
- REGARDLESS OF TROPICAL DEVELOPMENT, AN INFLUX OF TROPICAL
MOISTURE WILL BRING LOW TO MEDIUM (20-50%) PRECIPITATION
CHANCES FRIDAY AND SATURDAY, WITH THE HIGHEST CHANCES
ALONG/EAST OF US-281/I-69C. ADDITIONALLY, THERE WILL BE
INCREASED SWELL AND RIP CURRENTS ALONG THE LOWER TEXAS BEACHES.
- REMEMBER TO HAVE TRUSTED SOURCES FOR WEATHER INFORMATION, SUCH
AS THE NATIONAL HURRICANE CENTER, LOCAL OFFICIALS, MEDIA
OUTLETS, AND OUR LOCAL OFFICE!
DISCUSSION
ISSUED AT 1252 PM CDT WED AUG 13 2025
BOTTOM LINE: SUMMERTIME HEAT WILL CONTINUE TO BE THE MAIN WEATHER
CONCERN THROUGH THURSDAY, BUT OUR ATTENTION WILL QUICKLY SHIFT TO
UNSETTLED WEATHER AS A TROPICAL WAVE APPROACHES BY THE END OF THE
WEEK.
HIGH TEMPERATURES RANGING FROM THE UPPER 90S TO ALONG/EAST OF
I-69E AND TRIPLE DIGITS FURTHER INLAND THIS AFTERNOON AND THURSDAY.
PERSISTENT LOW LEVEL SOUTHERLY TO SOUTHEASTERLY FLOW WILL KEEP
THE HUMIDITY ELEVATED, AND IN COMBINATION WITH THE HEAT, WILL
RESULT IN TRIPLE-DIGIT HEAT INDEX VALUES. ISOLATED SHOWERS AND
THUNDERSTORMS MAY DEVELOP ALONG THE SEA BREEZE ONCE AGAIN, WITH A
PRIMARY THREAT FOR GUSTY WINDS, BRIEF HEAVY RAINFALL, AND
LIGHTNING. ANY DEVELOPMENT WILL DISSIPATE WITH THE LOSS OF DAYTIME
HEATING.
MEANWHILE, A TROPICAL WAVE, CURRENTLY LOCATED OVER OF THE YUCATAN
PENINSULA, IS EXPECTED TO TRACK TOWARD THE BAY OF CAMPECHE LATER
TODAY. THIS SYSTEM WILL CONTINUE TO TRACK WEST-NORTHWEST OR
NORTHWEST TOWARDS THE WESTERN GULF COASTLINE THROUGH FRIDAY. THE
NATIONAL HURRICANE CENTER MAINTAINS A LOW CHANCE (10%) OF
DEVELOPMENT THROUGH THE NEXT 48 HOURS. REGARDLESS OF ANY TROPICAL
DEVELOPMENT, THIS FEATURE WILL BRING AN INFLUX OF TROPICAL
MOISTURE ACROSS MOST OF DEEP SOUTH TEXAS, WITH MODEL GUIDANCE
INDICATING PRECIPITABLE WATER VALUES RANGING FROM 2.3-2.4 INCHES
ALONG AND EAST OF US-281/I-69C BY FRIDAY AFTERNOON AND REMAINING
THROUGH SATURDAY AFTERNOON. THIS SHOULD RESULT IN SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS BEGINNING LATE FRIDAY MORNING
OR EARLY FRIDAY AFTERNOON, INITIALLY ALONG THE IMMEDIATE COAST AND
GULF WATERS BEFORE SPREADING FURTHER INLAND. TAKING A LOOK AT
PROBABILISTIC GUIDANCE, THE NBM 90TH PERCENTILE HIGHLIGHTS 48-HOUR
RAINFALL AMOUNTS (ENDING 7 AM SUNDAY MORNING) ALONG AND EAST OF
US-281/I-69E RANGING FROM 1-1.5 INCHES FOR THE DURATION OF THIS
EVENT. STILL, PROBABILISTIC GUIDANCE INDICATES THE MOST LIKELY
FORECAST RAINFALL AMOUNTS FOR THIS TIME PERIOD RANGE FROM AROUND
0.1-0.5 INCHES. GIVEN THE EFFICIENT RAIN-PRODUCING ENVIRONMENT,
LOCALLY HEAVY RAINFALL UPWARDS OF 1 INCH CANNOT BE RULED OUT. THIS
MAY RESULT IN MINOR/NUISANCE FLOODING ISSUES ALONG LOW-LYING OR
FLOOD- PRONE AREAS.
IN ADDITION TO AN UPTICK IN PRECIPITATION CHANCES REGION WIDE, IT
IS LIKELY THAT WE’LL BEGIN TO SEE AN INCREASED RISK OF RIP
CURRENTS AND INCREASING SWELL ALONG THE LOWER TEXAS BEACHES AS THE
TROPICAL WAVE APPROACHES THE WESTERN GULF COASTLINE. CONDITIONS
SHOULD BEGIN TO IMPROVE BY LATE SUNDAY OR MONDAY. OTHERWISE,
INCREASING CLOUD COVER ASSOCIATED WITH THIS SYSTEM SHOULD DROP
AFTERNOON TEMPERATURES A FEW DEGREES ON FRIDAY AND SATURDAY. BY
SUNDAY AND EARLY NEXT WEEK, GENERALLY RAIN-FREE CONDITIONS WILL
RETURN OUTSIDE OF ANY ACTIVITY THAT DEVELOPS ALONG THE SEA BREEZE
EACH AFTERNOON.
AVIATION
(18Z TAFS)
ISSUED AT 1252 PM CDT WED AUG 13 2025
VFR AND SOUTHEAST WINDS WILL PREVAIL THROUGH THE FORECAST PERIOD
AT ALL TAF SITES. OCCASIONAL GUSTS TO 15-20 KNOTS CANNOT BE RULED
OUT DURING THE AFTERNOON HOURS. OTHERWISE, ISOLATED CONVECTION MAY
DEVELOP ALONG THE SEA BREEZE THIS AFTERNOON BUT CONFIDENCE IN
LOCATION IS TOO LOW TO WARRANT A MENTION AT THIS TIME. THE MAIN
IMPACTS WITH ANY CONVECTION ARE BRIEF HEAVY RAINFALL, GUSTY WINDS,
LIGHTNING, AND BRIEF MVFR/IFR CEILINGS/VISIBILITY.
MARINE
ISSUED AT 1252 PM CDT WED AUG 13 2025
GENERALLY FAVORABLE MARINE CONDITIONS WILL PREVAIL THROUGH
THURSDAY WITH LIGHT TO MODERATE SOUTHEAST WINDS AND LOW TO
MODERATE SEAS. ISOLATED TO SCATTERED SHOWERS MAY DEVELOP EACH
MORNING OVER THE GULF WATERS. CONDITIONS BECOME LESS FAVORABLE
FRIDAY AND SATURDAY AS A TROPICAL WAVE APPROACHES. EXPECT
INCREASING WAVE HEIGHTS AND LOW TO MEDIUM PRECIPITATION CHANCES
(30-50%) RETURN FRIDAY AND SATURDAY OVER THE GULF WATERS.
PRELIMINARY POINT TEMPS/POPS
BROWNSVILLE 80 97 80 94 / 0 10 10 40
HARLINGEN 76 100 77 95 / 0 10 0 40
MCALLEN 80 102 80 99 / 0 0 0 40
RIO GRANDE CITY 78 104 77 100 / 10 0 0 30
SOUTH PADRE ISLAND 82 90 82 88 / 0 10 10 50
BAYVIEW/PORT ISABEL 79 95 79 92 / 0 10 10 40
BRO WATCHES/WARNINGS/ADVISORIES
TX...NONE.
GM...NONE.
SHORT TERM...22-GARCIA
LONG TERM....22-GARCIA
AVIATION...22-GARCIA
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