564  
FXUS64 KBRO 190540 AAA  
AFDBRO  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE BROWNSVILLE TX  
1240 AM CDT SAT SEP 19 2026  
   
..NEW AVIATION  
 
   
KEY MESSAGES  
 
UPDATED AT 1237 AM CDT SAT SEP 19 2026  
 
- DAILY LOW MEDIUM (20-40% OR HIGHER) CHANCES OF RAIN RETURN NEXT  
MONDAY AND BECOME REGION-WIDE BY NEXT TUESDAY.  
 
- TEMPERATURES EASE OFF A FEW DEGREES FROM WIDESPREAD AREAS OF  
LOW 100S ALONG/WEST I-69 E TO MOSTLY UPPER 90S BY TUESDAY.  
 
- EXTREME RISKS OF HEAT-RELATED ILLNESSES (LEVEL 4/4) ARE LIKELY  
TO CONTINUE FOR PORTIONS OF THE RGV/RIO GRANDE PLAINS WHILE THE  
REST OF THE REGION EXPERIENCES MODERATE TO MAJOR RISKS (LEVEL  
2/4 AND 3/4).  
 
- A MODERATE RISK OF LIFE-THREATENING RIP CURRENTS CONTINUES  
THROUGH SATURDAY AFTERNOON.  
 
 
   
DISCUSSION  
 
ISSUED AT 1040 PM CDT FRI SEP 18 2026  
 
A BIT OF A DYNAMIC AND SOMEWHAT UNSETTLED WEATHER PATTERN SETS UP  
ACROSS DEEP SOUTH TEXAS THROUGHOUT THE NEXT 7 DAYS OR INTO LATE NEXT  
WEEK. SUBSIDENCE AND DRIER AIR ASSOCIATED WITH A 591-594+ DAM HIGH  
PRESSURE ALOFT OVER NORTHEAST TEXAS LOWERS MOISTURE CONTENT TONIGHT  
THROUGH SUNDAY, CUTTING DOWN ON RAIN CHANCES TO, AT MOST, A LOW  
(15%) CHANCE OF AN ISOLATED SHOWER OR TWO OVER THE SOUTHERN  
PORTIONS OF THE LOWER AND MID RGV. MEANWHILE, HEIGHTS GRADUALLY  
LOWER AS THE HIGH BECOMES WEDGED BETWEEN AN UPPER LEVEL LOW  
REGRESSING TO THE EASTERN GULF AND AS ANOTHER PUSHES EAST FROM  
THE INTERMOUNTAIN WEST TO THE PLAINS BY MONDAY. FOLLOWING, THE  
COMBINATION OF ENHANCED LIFT OVER THE GULF RESULTING FROM A SERIES  
OF HIGH PRESSURE SURGES AND A BIT OF NEARBY MID/UPPER LEVEL  
TROUGH VORTICITY ADVECTION ALONG THE SOUTHEASTERN PERIPHERY OF A  
HIGH PRESSURE ALOFT EMERGING OVER THE SOUTHERN PLAINS RE-ENHANCES  
MOISTURE CONTENT AND CHANCES OF RAIN. AS A RESULT, DAILY LOW TO  
MEDIUM (20-40% OR HIGHER) CHANCES OF RAIN ALONG THE DAYTIME  
SEABREEZE BOUNDARY EXPAND FROM ALONG/EAST US-281 NEXT MONDAY TO  
MOST OF THE REGION BY NEXT TUESDAY. HEAVY RAIN AND NUISANCE  
FLOODING ARE POSSIBLE AS PWAT VALUES INCREASE, ESPECIALLY TOWARD  
THE MIDDLE AND LATER PARTS OF THE WEEK. STILL SHOULD NOTE THAT  
THIS IS SUBJECT TO CHANGE AND WILL DEPEND ON THE POSITIONING AND  
STRENGTH OF THE HIGH PRESSURE ALOFT.  
 
WIDESPREAD LOWER 100S ACROSS THE NORTHERN RANCHLANDS ALONG/WEST OF I-  
69 E AND ACROSS THE RGV/RIO GRANDE PLAINS ALONG/WEST US-281 ARE  
EXPECTED SATURDAY THROUGH MONDAY, SLIGHTLY COOLING OFF TO MOSTLY THE  
UPPER 90S BY TUESDAY AS CLOUDS BUILD. ADDITIONALLY, AREAS OF EXTREME  
HEAT-RELATED ILLNESSES ACROSS PORTIONS OF THE RGV/RIO GRANDE PLAINS  
CONTINUE THROUGH MONDAY AND THEN BECOME MORE LIMITED TO THE LOWER  
RGV BY TUESDAY WHILE THE REST OF THE REGION EXPERIENCES MODERATE TO  
MAJOR RISKS. SPSS FOR HEAT INDICES OF 108-111 F ARE POSSIBLE AS  
WELL.  
 
 
   
AVIATION  
 
(06Z TAFS)  
ISSUED AT 1237 AM CDT SAT SEP 19 2026  
 
MOSTLY CLEAR SKIES WITH LIGHT AND VARIABLE WINDS PREVAIL ACROSS  
DEEP SOUTH TEXAS EARLY THIS MORNING. LIGHT WINDS OVERNIGHT ARE  
FORECAST TO INCREASE AND BECOME EASTERLY LATER THIS MORNING INTO  
THE AFTERNOON. VFR CONDITONS WILL CONTINUE FOR THE NEXT 24 HOURS.  
 
 
   
MARINE  
 
ISSUED AT 1040 PM CDT FRI SEP 18 2026  
 
LIGHT TO GENTLE, OCCASIONALLY MODERATE, EASTERLY TO SOUTHEASTERLY  
WINDS BECOME GENTLE TO MODERATE NORTHEASTERLY TO EASTERLY ON TUESDAY  
AND MOSTLY MODERATE BY LATE WEEK. SLIGHT TO MODERATE (2-4 FT) SEAS  
EASE TO SLIGHT (1-2 FT) SEAS ON SUNDAY BEFORE INCREASING BACK TO  
MODERATE LATER IN THE WEEK. LOW (15-30%) CHANCES OF RAIN TONIGHT  
DECREASE TO 10% OR LESS BY SATURDAY AFTERNOON. LOW CHANCES RETURN ON  
SUNDAY, INCREASING TO LOW TO MEDIUM BY TUESDAY.  
 
 
   
PRELIMINARY POINT TEMPS/POPS  
 
BROWNSVILLE 96 79 96 80 / 10 0 10 0  
HARLINGEN 98 74 99 76 / 10 0 10 0  
MCALLEN 101 78 101 79 / 10 0 10 0  
RIO GRANDE CITY 102 77 102 78 / 0 0 0 0  
SOUTH PADRE ISLAND 89 81 89 81 / 10 10 10 10  
BAYVIEW/PORT ISABEL 94 78 95 78 / 10 0 10 0  
 
 
   
BRO WATCHES/WARNINGS/ADVISORIES  
 
TX...NONE.  
GM...NONE.  
 
 
 
 
SHORT TERM...65-IRISH  
LONG TERM....65-IRISH  
AVIATION...63-KC  
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab TX Page
Main Text Page