943
FXUS64 KBRO 181754
AFDBRO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BROWNSVILLE TX
1254 PM CDT MON MAY 18 2026
..NEW DISCUSSION, AVIATION, MARINE
KEY MESSAGES
UPDATED AT 1242 PM CDT MON MAY 18 2026
KEY MESSAGES:
* HEAT RISK FOR TODAY AND TOMORROW IS A MIXTURE OF MODERATE AND
MAJOR.
* STRONG TO SEVERE THUNDERSTORMS ALONG WITH HEAVY RAINFALL AND
LOCALIZED FLOODING IS POSSIBLE STARTING WEDNESDAY THROUGH
FRIDAY.
* A SMALL CRAFT ADVISORY HAS BEEN EXTENDED TILL 9 AM CDT TUESDAY;
A HIGH RISK FOR RIP CURRENTS CONTINUES THROUGH TUESDAY EVENING
AS WELL.
DISCUSSION
ISSUED AT 1242 PM CDT MON MAY 18 2026
WHILE THE HEAT WILL CONTINUE TO LINGER AS A POTENTIAL HAZARD WITH
HIGH TEMPERATURES IN THE UPPER 90S TO LOWER TRIPLE DIGITS FOR TODAY
AND TOMORROW. THE HIGH TEMPERATURES FOR WEDNESDAY DO SLIGHTLY LOWER
TO MOSTLY IN THE MID 90S AS CLOUD COVERAGE STARTS TO INCREASE, WHICH
WILL BE FURTHER DISCUSSED LATER ON. THE HEAT INDICES FOR TODAY AND
TOMORROW DO GENERALLY FLOAT AROUND 108 F. WHILE STILL BELOW THE HEAT
ADVISORY CRITERIA, THE HEAT RISK FOR TODAY AND TOMORROW IS MODERATE
(LEVEL 2 OF 4) AND MAJOR (LEVEL 3 OF 4). THUS IT WILL STILL BE
IMPORTANT TO PRACTICE HEAT SAFETY WHEN POSSIBLE ESPECIALLY TO THOSE
THAT ARE VULNERABLE TO HEAT RELATED ILLNESSES.
BY WEDNESDAY, CLOUD COVERAGE IS EXPECTED TO INCREASE OVER THE REGION
AS A FRONTAL BOUNDARY STALLS TO THE NORTH OF THE REGION. WITH THE
COMBINATION OF SOUTHWESTERLY FLOW ALOFT, SOUTHEASTERLY FLOW AT THE
SURFACE, AND THE FRONTAL BOUNDARY TO THE NORTH. THE ENVIRONMENT WILL
BECOME MORE FAVORABLE FOR THE DEVELOPMENT OF SHOWERS AND
THUNDERSTORMS. AS OF THIS CURRENT FORECAST THE BEST CHANCES FOR RAIN
ARE ON THURSDAY AND FRIDAY WITH RAIN CHANCES BETWEEN 60 TO 80%
DURING THOSE DAYS. WHILE CHANCES ARE GENERALLY MEDIUM (AROUND 50%)
FOR WEDNESDAY AND THE REST OF THE FORECAST PERIOD. CURRENTLY THE
WEATHER PREDICTION CENTER DOES HAVE ALL OF DEEP SOUTH TEXAS AND THE
RIO GRANDE VALLEY IN A MARGINAL RISK (LEVEL 1 OF 4) FOR EXCESSIVE
RAINFALL DAYS 3 THROUGH 5, WHICH COVERS WEDNESDAY MORNING THROUGH
SATURDAY MORNING. THUS IT WILL BE POSSIBLE TO SEE SOME FLOODING
DUE TO THE RAINFALL. THE STORM PREDICTION CENTER ALSO HAS A
MARGINAL RISK (LEVEL 1 OF 5) FOR SEVERE WEATHER FOR MOSTLY THE
UPPER VALLEY FOR TUESDAY THROUGH WEDNESDAY. HOWEVER THE REST OF
THE REGION IS IN A GENERAL THUNDERSTORM OUTLOOK THUS IT IS
POSSIBLE FOR SHOWERS AND THUNDERSTORMS TO OCCUR ALL OVER THE AREA
THAT DAY.
LASTLY FOR THE COASTAL HAZARDS, WHILE THE COASTAL FLOOD STATEMENT
WAS ALLOWED TO EXPIRE EARLY THIS AFTERNOON, BUT IT IS POSSIBLE THAT
ANOTHER COASTAL FLOOD STATEMENT MIGHT BE NEEDED TONIGHT. A HIGH RISK
OF RIP CURRENTS IS IN EFFECT THROUGH TUESDAY EVENING.
AVIATION
(18Z TAFS)
ISSUED AT 1242 PM CDT MON MAY 18 2026
GUSTY SOUTHEASTERLY WINDS ARE EXPECTED TO CONTINUE THROUGH THE
AFTERNOON HOURS AND INTO THE EARLY EVENING HOURS. WHILE THE WINDS
ARE GENERALLY EXPECTED TO DIMINISH DURING THAT TIME FRAME. VFR
CONDITIONS SHOULD PERSIST THROUGH THE EVENING, BUT A RETURN OF
MVFR COULD OCCUR DURING THE OVERNIGHT HOURS. HOWEVER THE CEILING
SHOULD RETURN TO VFR DURING THE MORNING HOURS TOMORROW WITH AS THE
SOUTHEASTERLY WINDS BECOME GUSTY AGAIN TOMORROW MORNING AS WELL.
MARINE
ISSUED AT 1242 PM CDT MON MAY 18 2026
HAZARDOUS MARINE CONDITIONS ARE EXPECTED TO PERSIST
THROUGH MOST OF TONIGHT AND INTO EARLY TOMORROW MORNING, THUS A
SMALL CRAFT ADVISORY REMAINS IN EFFECT UNTIL 9 AM TOMORROW. EVEN
AFTER THE SMALL CRAFT ADVISORY DOES EXPIRE TOMORROW MORNING, ADVERSE
CONDITIONS ARE STILL EXPECTED FOR MOST OF THE DAY TOMORROW AS SEAS
WILL TAKE MORE TIME TO COME DOWN. SHOWERS AND THUNDERSTORMS ARE
EXPECTED TO RETURN TO THE REGION BY WEDNESDAY AND WILL CONTINUE TO
PERSIST THROUGH THE FORECAST PERIOD.
PRELIMINARY POINT TEMPS/POPS
BROWNSVILLE 81 94 81 92 / 10 10 20 10
HARLINGEN 79 95 79 93 / 10 0 40 10
MCALLEN 81 97 79 94 / 20 10 30 20
RIO GRANDE CITY 79 98 78 95 / 20 10 40 30
SOUTH PADRE ISLAND 81 86 81 85 / 10 10 20 10
BAYVIEW/PORT ISABEL 80 92 80 90 / 10 0 30 10
BRO WATCHES/WARNINGS/ADVISORIES
TX...WIND ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR TXZ254-255-351-
354-355-451-454-455.
HIGH RIP CURRENT RISK THROUGH TUESDAY EVENING FOR TXZ451-454-455.
GM...SMALL CRAFT ADVISORY UNTIL 9 AM CDT TUESDAY FOR GMZ130-132-135-
150-155-170-175.
SHORT TERM...64-KATZ
LONG TERM....64-KATZ
AVIATION...64-KATZ
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