796  
FXUS64 KBRO 172312 AAA  
AFDBRO  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE BROWNSVILLE TX  
612 PM CDT THU SEP 17 2026  
   
..NEW AVIATION  
 
   
KEY MESSAGES  
 
UPDATED AT 606 PM CDT THU SEP 17 2026  
 
- A SPECIAL WEATHER STATEMENT IS IN EFFECT FOR THE INLAND COASTAL  
COUNTIES FOR ELEVATED HEAT INDICES THIS AFTERNOON.  
 
- THERE IS A LOW TO MODERATE (20 TO 40%) CHANCE OF SHOWERS AND  
THUNDERSTORMS ACROSS DEEP SOUTH TEXAS TODAY AND TOMORROW.  
 
- MODERATE (LEVEL 2 OF 4) TO MAJOR (LEVEL 3 OF 4) HEAT RISK WILL  
CONTINUE TO REMAIN A CONCERN OVER THE NEXT WEEK.  
 
- CONDITIONS SHOULD BE DRIER FOR THE WEEKEND, BUT LOW TO MODERATE  
RAIN CHANCES RETURN EARLY NEXT WEEK.  
 
 
   
DISCUSSION  
 
ISSUED AT 1222 PM CDT THU SEP 17 2026  
 
AN UNSETTLED WEATHER PATTERN CONTINUES OVER THE NEXT FEW DAYS AS AN  
AREA OF STRONG HIGH PRESSURE OVER THE SOUTHEASTERN CONUS BACKBUILDS  
WESTWARD, WITH NORTHEASTERLY UPPER LEVEL FLOW BENEATH THE UNDERSIDE  
OF OF THIS HIGH REACHING DEEP SOUTH TEXAS. BECAUSE THIS  
NORTHEASTERLY AIRMASS HAS SPENT CONSIDERABLE TIME OVER THE GULF,  
THE ATMOSPHERIC PROFILE IS EXPECTED TO REMAIN DEEPLY MOIST FOR  
THE NEXT FEW DAYS, WITH PWATS INCREASING TO OVER 2 INCHES. THIS  
WILL SUPPORT LOW TO MODERATE (20 TO 40%) RAIN CHANCES TODAY AND  
TOMORROW. THE RAIN IS EXPECTED TO BE OVERALL BENEFICIAL, WITH MOST  
AREAS RECEIVING NO MORE THAN HALF AN INCH. HOWEVER, SOME HEAVIER  
SHOWERS AND THUNDERSTORMS COULD CAUSE LOCALLY HIGHER AMOUNTS WITH  
THE POTENTIAL FOR NUISANCE PONDING.  
 
AS HIGH PRESSURE CONTINUES TO BUILD WESTWARD OVER NORTHEASTERN TEXAS  
THOUGH THE WEEKEND, UPPER-LEVEL SUBSIDENCE SHOULD HELP DRY OUT  
CONDITIONS FOR THE WEEKEND. A SHOWER OR TWO CANNOT BE RULED OUT  
ALONG THE SEA BREEZE, BUT RAIN CHANCES REMAIN BELOW 20% FOR BOTH  
SATURDAY AND SUNDAY. RAIN CHANCES ARE EXPECTED TO PICK UP AGAIN NEXT  
WEEK AS HIGH PRESSURE AND SUBSIDENCE WEAKEN BUT WITH CONTINUED  
EAST-NORTHEASTERLY MOIST UPPER-LEVEL FLOW. SEA BREEZE ACTIVITY IS  
POSSIBLE EACH DAY NEXT WEEK (MOSTLY EAST OF I-69C), AND SOME  
LONGER-RANGE GUIDANCE HINTS AT A PATTERN SHIFT/POTENTIAL  
SHORTWAVE DISTURBANCE LATER NEXT WEEK THAT COULD BRING WIDESPREAD  
LOW TO MODERATE RAIN CHANCES TO ALL OF DEEP SOUTH TEXAS.  
 
HEAT RISK WILL REMAIN A CONCERN OVER THE NEXT WEEK. THOUGH  
INCREASED CLOUD COVER AND RAIN CHANCES MAY BRING SOME SMALL  
TEMPERATURE RELIEF BY A FEW DEGREES, THE HUMID AIRMASS WILL CONTINUE  
TO KEEP HEAT INDICES HIGH. A SPECIAL WEATHER STATEMENT IS IN EFFECT  
TODAY FOR THE INLAND COASTAL COUNTIES, WHERE HEAT INDICES COULD  
REACH BETWEEN 108-111 DEGREES THIS AFTERNOON. MODERATE (LEVEL 2 OF  
4) TO MAJOR (LEVEL 3 OF 4) HEAT RISK IS EXPECTED TO CONTINUE  
THROUGHOUT THE NEXT WEEK.  
 
 
   
AVIATION  
 
(00Z TAFS)  
ISSUED AT 606 PM CDT THU SEP 17 2026  
 
GENTLE TO MODERATE EAST-NORTHEASTERLY WINDS THIS EVENING BECOME  
LIGHT AND/OR VARIABLE OVERNIGHT TONIGHT BEFORE RETURNING TOMORROW  
AFTERNOON. A BRIEF PERIOD OF LIGHT RAIN OR TWO IS POSSIBLE  
OVERNIGHT AT KHRL AND KBRO, WITH THE BEST CHANCES TOMORROW  
MORNING BEFORE SPREADING EAST TO KMFE TOMORROW AFTERNOON. BRIEF  
LIGHT TO MODERATE, PERHAPS ISOLATED HEAVY, PASSING SHOWERS MAY  
INTERMITTENTLY REDUCE VISIBILITY, LEADING TO POSSIBLE SHORT  
PERIODS OF MVFR AS NOTED IN THE PROB30S.  
 
 
   
MARINE  
 
ISSUED AT 1222 PM CDT THU SEP 17 2026  
 
FAVORABLE CONDITIONS ARE EXPECTED OVER THE NEXT SEVERAL DAYS WITH  
LIGHT TO MODERATE NORTHEASTERLY WINDS AND LOW TO MODERATE (2 TO 4  
FEET) WAVE HEIGHTS. OFFSHORE SHOWERS AND THUNDERSTORMS ARE  
POSSIBLE THROUGHOUT THE NEXT WEEK, WHICH COULD TEMPORARILY  
DETERIORATE CONDITIONS IN THEIR IMMEDIATE VICINITY.  
 
 
   
PRELIMINARY POINT TEMPS/POPS  
 
BROWNSVILLE 79 95 78 95 / 20 20 10 20  
HARLINGEN 76 97 74 98 / 30 20 10 10  
MCALLEN 79 98 77 99 / 10 30 10 10  
RIO GRANDE CITY 78 98 75 100 / 30 20 10 0  
SOUTH PADRE ISLAND 81 88 81 88 / 30 30 20 10  
BAYVIEW/PORT ISABEL 78 94 77 94 / 30 30 10 10  
 
 
   
BRO WATCHES/WARNINGS/ADVISORIES  
 
TX...NONE.  
GM...NONE.  
 
 
 
 
SHORT TERM...55-MM  
LONG TERM....55-MM  
AVIATION...65-IRISH  
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