786  
FXUS64 KBRO 111718  
AFDBRO  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BROWNSVILLE TX  
1218 PM CDT MON AUG 11 2025  
   
..NEW DISCUSSION, AVIATION, MARINE
 
 
   
DISCUSSION
 
 
ISSUED AT 1212 PM CDT MON AUG 11 2025  
 
CONVERGENCE ALONG SEABREEZE BOUNDARIES, DIURNAL INSTABILITY AND WEAK  
FORCING OVER DEEP SOUTH TEXAS ARE LIKELY TO CONTINUE TO GENERATE A  
NEAR DAILY LOW (20-30%) CHANCE OF BRIEF ISOLATED SHOWERS AND  
THUNDERSTORMS ALONG AND EAST OF I-69 C AS THE REGION CONTINUES TO BE  
WEDGED BETWEEN A MID-LEVEL HIGH PRESSURE OVER THE DESERT SOUTHWEST  
AND ANOTHER OVER THE SOUTHERN AND SOUTHEASTERN US. HEAVY DOWNPOURS,  
LIGHTNING AND STRONGER GUSTS ARE POSSIBLE WITHIN THE STRONGEST OF  
CONVECTION. ALTHOUGH SUBJECT TO CHANGE, WE CURRENTLY ANTICIPATE THE  
BEST COVERAGE OF CONVECTION TO FALL ON WEDNESDAY AND FRIDAY AS A  
SERIES OF WEAK INVERTED TROUGHS PASS OVER THE REGION AS WELL LESS  
THAN A 15% CHANCE ON THURSDAY. AS THE WEEK PROGRESSES, THE MID-LEVEL  
HIGH TO THE EAST IS EXPECTED TO SLOWLY EXPAND AND SHIFT WESTWARD  
ACROSS THE GULF COAST, INCREASING SUBSIDENCE ALOFT AND REDUCING  
PROBABILITIES OF SHOWERS AND THUNDERSTORMS TO LESS THAN 15%,  
POSSIBLY BY SATURDAY AND INTO THE BEGINNING OF NEXT WEEK.  
 
TEMPERATURES ARE LIKELY TO REMAIN NEAR TO A FEW DEGREES ABOVE  
AVERAGE, WITH AFTERNOON HIGHS IN THE MID TO UPPER 90'S EAST OF I-69  
E AND NEAR OR ABOVE 100 DEGF TO THE WEST AS WELL AS MID 80'S TO THE  
MID 90'S ALONG AND NEAR THE COAST (COOLEST ALONG THE IMMEDIATE GULF  
COAST) WHILE OVERNIGHT LOWS IN THE 70'S INLAND AND LOWER 80'S AT THE  
COAST CONTINUE. MEANWHILE, SURFACE HIGH PRESSURE DOMINATING THE GULF  
MAINTAINS SOUTHEASTERLY WINDS, PUMPING MOISTURE INTO THE REGION,  
RESULTING IN PERSISTENT HUMID CONDITIONS AND AFTERNOON HEAT INDICES  
GENERALLY RANGING BETWEEN 100-110 DEGF THROUGHOUT THE PERIOD.  
SPECIAL WEATHER STATEMENTS, AND/OR A BRIEF HEAT ADVISORY, MAY BE  
POSSIBLE OVER THE WEEKEND AS REDUCED CLOUD COVERAGE AND INCREASED  
HUMIDITY COULD CAUSE INDICES TO REACH OR TOP 111 DEGF FOR A BRIEF  
PERIOD OF TIME IN THE AFTERNOON ACROSS PORTIONS OF THE CWA.  
OTHERWISE, A MAINLY MODERATE (LEVEL 2/4) HEAT RISK CONTINUES THROUGH  
NEXT MONDAY. POCKETS OF MAJOR (LEVEL 3/4) HEAT RISKS ARE LIKELY  
ACROSS THE RIO GRANDE VALLEY AND COASTAL COUNTIES, POSSIBLY  
EXPANDING IN AREA ON THURSDAY AND SATURDAY.  
 

 
   
AVIATION
 
 
(18Z TAFS)  
ISSUED AT 1212 PM CDT MON AUG 11 2025  
 
A MODERATE EAST-SOUTHEASTERLY TO SOUTHEASTERLY BREEZE, GUSTING UP  
TO 15-20 KNOTS, IS LIKELY TO PERSIST THROUGH THE REST OF THIS  
AFTERNOON AND INTO THIS EVENING, SETTLING DOWN TO A LIGHT BREEZE  
(5-10 KNOTS) OVERNIGHT. THERE IS A LOW (20-30%) CHANCE OF ISOLATED  
SHOWERS AND THUNDERSTORMS THIS AFTERNOON, WHICH COULD BRIEFLY  
REDUCE CEILINGS AND VISIBILITY DOWN TO MVFR. OTHERWISE, VFR  
CONDITIONS PREVAIL WITH WINDS PICKING BACK UP TO MODERATE EARLY  
TUESDAY AFTERNOON.  
 

 
   
MARINE
 
 
ISSUED AT 1212 PM CDT MON AUG 11 2025  
 
SURFACE HIGH PRESSURE OVER THE GULF CONTINUES TO RESULT IN MOSTLY  
FAVORABLE MARINE CONDITIONS WITH A GENTLE TO MODERATE SOUTHEASTERLY  
TO SOUTHERLY BREEZE AND SLIGHT TO MODERATE (1-3 FEET) SEAS. THERE IS  
A LOW TO MEDIUM (20-40%) CHANCE OF BRIEF SHOWERS AND THUNDERSTORMS  
DURING THE DAYTIME WEDNESDAY THROUGH FRIDAY, WITH THE HIGHEST  
PROBABILITIES OVER THE EASTERN OFFSHORE (20-60 NM) GULF WATERS.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
BROWNSVILLE 79 96 79 96 / 0 20 10 20  
HARLINGEN 75 98 75 98 / 0 20 0 20  
MCALLEN 79 102 79 102 / 10 20 10 20  
RIO GRANDE CITY 78 103 78 102 / 10 20 10 10  
SOUTH PADRE ISLAND 81 88 81 89 / 0 10 10 10  
BAYVIEW/PORT ISABEL 78 94 78 94 / 0 10 0 20  
 

 
   
BRO WATCHES/WARNINGS/ADVISORIES
 
 
TX...NONE.  
GM...NONE.  

 
 

 
 
SHORT TERM...65-IRISH  
LONG TERM....65-IRISH  
AVIATION...65-IRISH  
 
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