184
FXUS64 KBRO 182337 AAA
AFDBRO
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
637 PM CDT TUE AUG 18 2026
..NEW AVIATION
KEY MESSAGES
UPDATED AT 636 PM CDT TUE AUG 18 2026
- HOT, DRY, AND AT TIMES BREEZY CONDITIONS WILL CONTINUE THROUGH
THE WEEK AND INTO THE WEEKEND.
- MODERATE (LEVEL 2 OF 4) TO MAJOR RISK (3 OF 4) OF HEAT-RELATED
IMPACTS THROUGH THE WEEKEND WITH PEAK AFTERNOON HEAT INDICES
GENERALLY BETWEEN 105 TO 112 DEGREES.
- THERE IS INCREASED POTENTIAL FOR WILDFIRE SPREAD WEDNESDAY INTO
THURSDAY DUE TO GUSTY CONDITIONS AND DRYING FUELS.
DISCUSSION
ISSUED AT 114 PM CDT TUE AUG 18 2026
THE DOG DAYS OF SUMMER ARE HERE AS A LA CANICULA RIDGE TAKES HOLD
ACROSS THE DESERT SOUTHWEST, NORTHERN MEXICO INTO THE WESTERN GULF
STATES. THERE IS STRONG CONSENSUS AMONG THE GFS, ECMWF, AND CMC
ENSEMBLE GUIDANCE WITH AN ANOMALOUSLY STRONG 594 DM RIDGE DRAPED
OVER OUR REGION FOR THE NEXT TWO WEEKS. WHILE THE SUPER EL NINO HAS
HELPED KEEP THE TROPICAL SYSTEMS AWAY FROM THE GULF COAST AND
ATLANTIC BASIN, WE DO NEED THE RAIN AND UNFORTUNATELY, OUR DROUGHT
SITUATION WILL LIKELY GET WORSE BEFORE ANY MEANINGFUL CHANCES FOR
RELIEF. INDEED, THE 6-10 DAY CPC OUTLOOKS SHOW A 60-70 PERCENT
PROBABILITY OF ABOVE NORMAL TEMPERATURES AND 40-50 PERCENT
PROBABILITY OF BELOW NORMAL RAINFALL FOR DEEP SOUTH TEXAS. EVERY DAY
IS PRETTY MUCH RINSE AND REPEAT UNTIL FURTHER NOTICE. THERE MIGHT BE
AN ISOLATED SHOWER OR EVEN A THUNDERSTORM ALONG THE SEA BREEZE
BOUNDARY EACH AFTERNOON, BUT THE OVERALL PATTERN TENDS TO SUPPRESS
RAINFALL AND CONVECTION CHANCES.
DAILY HIGH TEMPERATURES ARE EXPECTED TO RANGE FROM THE THE UPPER 90S
TO AROUND 105 DEGREES, EXCEPT NEAR THE COAST. THE COMBINATION OF HOT
TEMPERATURES AND ELEVATED DEWPOINTS IN THE 70S WILL SUPPORT HEAT
INDICES GENERALLY BETWEEN 105 TO 110 DEGREES EACH AFTERNOON. HEAT
INDICES MAY BRIEFLY REACH 111+ AT A FEW LOCATIONS IN THE AFTERNOON,
ESPECIALLY THURSDAY AND FRIDAY. WIDESPREAD MODERATE (LEVEL 2 OF 4)
TO MAJOR (LEVEL 3 OF 4) HEAT RISK EXPECTED THROUGH LATE WEEK INTO
THE WEEKEND. WHETHER A SPECIAL WEATHER STATEMENT OR HEAT ADVISORY IS
ISSUED FOR YOUR AREA, BE SURE TO EXERCISE CAUTION IF SPENDING TIME
OUTDOORS AND ALWAYS LOOK BEFORE YOU LOCK.
THE HOT, DRY, AND AT TIMES BREEZY CONDITIONS WILL SUPPORT THE
POTENTIAL INCREASE OF FIRE WEATHER CONCERNS WEDNESDAY INTO THURSDAY.
THE CURRENT D1 (MODERATE) TO D2 (SEVERE) DROUGHT COVERAGE LOOKS TO
EXPAND FURTHER WITH THE UPCOMING U.S. DROUGHT MONITOR. WITH SUCH DRY
ANTECEDENT CONDITIONS, EVAPOTRANSPIRATION RATES ARE EXTREMELY HIGH.
THE DAILY EVAPOTRANSPIRATION RATES HAVE RANGED BETWEEN 0.4 AND 0.5
INCHES PER DAY HERE AT WFO BROWNSVILLE. COMBINED WITH A 24-HOUR WIND
RUN OF 100 TO 200 MILES EACH DAY, THIS REPRESENTS EXTREME, PEAK
ATMOSPHERIC WATER DEMAND. IN OTHER WORDS, WE HAVE A RATHER DIRE
SITUATION FROM A WATER RESOURCE MANAGEMENT AND AGRICULTURAL
STANDPOINT WITH WORSENING DROUGHT AND ONGOING HOT CONDITIONS. WITH
HOW RAPIDLY FUELS ARE DRYING OUT, IT IS NO SURPRISE THAT THE TEXAS
A&M FOREST SERVICE IS NOW FORECASTING HIGH TO VERY HIGH FIRE DANGER
FOR WEDNESDAY DUE TO A COMBINATION OF 15-20 MPH WINDS GUSTING 25+
MPH AT TIMES AND DRY FUELS BASED ON 100HR AND ERC PERCENTILES.
AVIATION
(00Z TAFS)
ISSUED AT 636 PM CDT TUE AUG 18 2026
MODERATE SOUTHEAST WINDS PREVAIL ACROSS DEEP SOUTH TEXAS EARLY
THIS EVENING. WINDS ARE EXPECTED TO GRADUALLY DECREASE LATER THIS
EVENING AND OVERNIGHT. SOUTHEAST WINDS WILL INCREASE AND BECOME
MODERATE AND GUSTY MID TO LATE MORNING. SOME GUSTS AROUND 25 KNOTS
WILL BE POSSIBLE IN THE AFTERNOON. VFR CONDITIONS ARE EXPECTED FOR
THE NEXT 24 HOURS.
MARINE
ISSUED AT 114 PM CDT TUE AUG 18 2026
GENERALLY FAVORABLE MARINE CONDITIONS WILL PREVAIL ALONG THE LOWER
TEXAS COAST THROUGH THE PERIOD WITH LIGHT TO MODERATE WINDS AND LOW
TO MODERATE SEAS. GENERALLY LOW TO MARGINALLY MODERATE RIP CURRENT
RISK IS EXPECTED AS WAVE PERIOD INCREASE TO THE 5-6 SECONDS RANGE
WITH A PERSISTENT SOUTHERLY TO SOUTH-SOUTHEASTERLY SWELL AND 2-3 FT
WAVES. 15-20 KT WINDS OVER THE LAGUNA MADRE MID TO LATE WEEK COULD
ALSO LEAD TO SMALL CRAFT EXERCISE CAUTION CONDITIONS. WITH SSTS IN
THE LOW 80S AND WATERS LOOKING INVITING WITH THE ONGOING HOT
WEATHER, PLEASE EXERCISE CAUTION AND BE AWARE OF RIP CURRENT RISK.
PRELIMINARY POINT TEMPS/POPS
BROWNSVILLE 80 97 82 98 / 0 0 0 0
HARLINGEN 76 101 78 102 / 0 0 0 0
MCALLEN 80 103 81 104 / 0 0 0 0
RIO GRANDE CITY 77 103 79 104 / 0 0 0 0
SOUTH PADRE ISLAND 81 90 82 90 / 0 0 0 0
BAYVIEW/PORT ISABEL 79 97 80 97 / 0 0 0 0
BRO WATCHES/WARNINGS/ADVISORIES
TX...NONE.
GM...NONE.
SHORT TERM...88-CHAI
LONG TERM....88-CHAI
AVIATION...63-KC
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