784
FXUS64 KBRO 160543 AAA
AFDBRO
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BROWNSVILLE TX
1243 AM CDT WED SEP 16 2026
..NEW AVIATION
KEY MESSAGES
UPDATED AT 1239 AM CDT WED SEP 16 2026
- A SPECIAL WEATHER STATEMENT (SPS) IS IN EFFECT FOR SOUTHERN
HIDALGO COUNTY AS WELL AS THE COASTAL AND INLAND PORTIONS OF
KENEDY, WILLACY AND CAMERON COUNTIES (MINUS THE BARRIER
ISLANDS) ON WEDNESDAY FOR HEAT INDICES OF 108-111 F, GENERALLY
OCCURRING WITHIN THE HOURS OF 11 AM TO 6 PM.
- NEAR RECORD-BREAKING HEAT AND MAJOR TO EXTREME RISKS OF HEAT
RELATED ILLNESSES (LEVELS 3/4 AND 4/4) ON WEDNESDAY IMPROVE TO
A MODERATE (LEVEL 2/4) TO MAJOR RISK BY THURSDAY.
- CHANCES OF RAIN INCREASE TO A LOW TO MEDIUM (30-60%) CHANCE AND
30-50% CHANCE ON THURSDAY AND FRIDAY, RESPECTIVELY, MINIMIZE
OVER THE WEEKEND AND INCREASE AGAIN NEXT WEEK.
- A LOW RISK OF LIFE-THREATENING RIP CURRENTS CONTINUES THROUGH
WEDNESDAY AFTERNOON.
DISCUSSION
ISSUED AT 1041 PM CDT TUE SEP 15 2026
THE FIRST FOCUS OF THE FORECAST REMAINS THE BRUTAL, NEAR RECORD
TRIPLE DIGIT HEAT EXPECTED AGAIN ON WEDNESDAY AS RIDGING ALOFT AND
PLENTIFUL SUNSHINE SOARS TEMPERATURES TO AROUND 6-8 DEGREES ABOVE
AVERAGE AND ENHANCING MOISTURE CAUSES HEAT INDICES TO MAX OUT
AROUND 105-111 F ACROSS THE REGION, WITH EXTREME RISKS OF HEAT-
RELATED ILLNESSES EXPECTED ACROSS MOST OF THE RGV/RIO GRANDE
PLAINS AND A MAJOR HEAT RISK ELSEWHERE. ONCE AGAIN, A SPS IS IN
EFFECT ON WEDNESDAY ACROSS THE LOWER AND MID RGV, NOT INCLUDING
THE BARRIER ISLANDS, FOR HEAT INDICES OF 108-111 F, POSSIBLY
BRIEFLY HOTTER.
THE SECOND FOCUS IS THE ANTICIPATED UNSETTLED WEATHER BROUGHT IN
BY A SLIGHT WEATHER PATTERN CHANGE; A 1020-1030 MB SURFACE HIGH
OVER THE EAST COAST SPILLS SOUTHWESTWARD TO THE GULF AND
TRANSITIONS WINDS TO EASTERLY BY WEDNESDAY MORNING, GUSTING TO
NEAR 20-25+ MPH IN THE AFTERNOON. THIS WILL AID IN ADVECTING
INLAND DEEP GULF MOISTURE ASSOCIATED WITH A DEVELOPING SHORTWAVE
TROUGH ALONG THE SOUTHERN PERIPHERY OF A RETREATING HIGH PRESSURE
ALOFT, MOISTENING PWAT VALUES THROUGHOUT WEDNESDAY, PEAKING AS
HIGH AS 2.0-2.4+ IN. WEDNESDAY NIGHT INTO FRIDAY BEFORE GRADUALLY
DRYING THROUGHOUT THE LATER HALF OF FRIDAY; CHANCES OF RAIN ALONG
THE DAYTIME SEABREEZE BOUNDARY INCREASE FROM A LOW (10-15%) CHANCE
ACROSS THE LOWER AND MID RGV ON WEDNESDAY TO A REGION-WIDE LOW TO
MEDIUM (30-60%) AND 20-50% CHANCE ON THURSDAY AND FRIDAY,
RESPECTIVELY. TOTAL FORECAST RAINFALL AMOUNTS THURSDAY INTO
FRIDAY HAVE TRENDED DOWN, ONLY EXPECTING UP TO 0.20 OF AN INCH.
HOWEVER, GIVEN SUCH HIGH MOISTURE CONTENT, HEAVY DOWNPOURS AND
SOME LOCALIZED MINOR FLOODING ARE POSSIBLE, PARTICULARLY WITHIN
ANY SLOWER-MOVING OR TRAINING OF THUNDERSTORMS ON THURSDAY AND
POSSIBLY FRIDAY, WHICH COULD QUICKLY DROP HALF AN INCH OR MORE OF
RAIN.
INCREASED CLOUD COVERAGE THURSDAY AND FRIDAY, FOLLOWED BY DRIER
AIR FUNNELING INTO THE REGION AS RIDGING RESUMES OVER THE WEEKEND,
SHOULD HELP COOL OFF TEMPERATURES TO MOSTLY THE UPPER 90S BY
THURSDAY, WHICH IS STILL AROUND 5 DEGREES ABOVE AVERAGE, AS WELL
AS IMPROVE HEAT RISKS FROM MODERATE TO MAJOR ON THURSDAY TO MOSTLY
MODERATE FRIDAY INTO SATURDAY. YET, MOISTURE AND TEMPERATURES
COULD REBOUND TOWARDS THE END OF THE WEEKEND, LEADING TO MODERATE
TO MAJOR HEAT RISKS WITH ADDITIONAL SPSS FOR HEAT ARE POSSIBLE BY
SUNDAY. LOW TO MEDIUM CHANCES OF RAIN RETURN NEXT WEEK, POTENTIALLY
KNOCKING DOWN TEMPERATURES AND IMPROVING HEAT RISKS AGAIN.
AVIATION
(06Z TAFS)
ISSUED AT 1239 AM CDT WED SEP 16 2026
VFR WILL PREVAIL AT THE AERODROMES THROUGH THE NEXT 24 HOURS.
LIGHT WINDS FOR THE REMAINDER OF THE OVERNIGHT HOURS WILL BECOME
MODERATE ON WEDNESDAY BEFORE DIMINISHING AROUND SUNSET. THE NEXT
ISSUANCE OF TAFS MAY NEED THE MENTION OF CONVECTION FOR AT LEAST
ONE OF THE AERODROMES IF HRRR MODEL GUIDANCE IS TO BE BELIEVED.
MARINE
ISSUED AT 1041 PM CDT TUE SEP 15 2026
GENTLE TO MODERATE SOUTHEASTERLY WINDS BECOME NORTHEASTERLY TO
EASTERLY ON WEDNESDAY AND EASTERLY TO SOUTHEASTERLY AGAIN OVER THE
WEEKEND. SLIGHT TO MODERATE (2-4 FT) SEAS BUILD TO MODERATE (3-5 FT)
THURSDAY BEFORE IMPROVING BACK TO SLIGHT TO MODERATE BY SUNDAY.
LOW TO MEDIUM (20-40%) CHANCES OF RAIN ON WEDNESDAY INCREASE TO A
MEDIUM TO LIKELY (40-70%) CHANCE ON THURSDAY FOLLOWED BY A LOW TO
MEDIUM (20-50%) CHANCE ON FRIDAY AND SATURDAY. CHANCES OF RAIN
CONTINUE INTO NEXT WEEK AS WELL.
PRELIMINARY POINT TEMPS/POPS
BROWNSVILLE 97 80 95 79 / 10 20 40 30
HARLINGEN 99 76 97 76 / 10 20 40 20
MCALLEN 103 80 99 79 / 10 10 60 20
RIO GRANDE CITY 103 78 99 78 / 10 0 50 20
SOUTH PADRE ISLAND 89 81 88 81 / 10 30 40 40
BAYVIEW/PORT ISABEL 95 78 94 78 / 10 20 40 30
BRO WATCHES/WARNINGS/ADVISORIES
NONE.
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