642  
FXUS64 KHGX 212316  
AFDHGX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX  
616 PM CDT TUE JUL 21 2026  
   
..NEW AVIATION  
 
   
KEY MESSAGES  
 
- A HEAT ADVISORY REMAINS IN EFFECT THROUGH 8 PM THIS EVENING.  
 
- EVEN HOTTER CONDITIONS ARE EXPECTED ON WEDNESDAY WITH  
DANGEROUSLY HEAT INDICES ACROSS ALL OF SOUTHEAST TEXAS. AN  
EXTREME HEAT WARNING HAS BEEN ISSUED FROM 11 AM - 8 PM  
WEDNESDAY.  
 
- TROPICAL STORM BERTHA IS FORECAST TO WEAKEN AS IT APPROACHES  
SOUTHEAST TEXAS LATE IN THE WEEK. WHILE FORECAST UNCERTAINTY  
REMAINS FAIRLY HIGH, RESIDENTS SHOULD MONITOR THE LATEST  
FORECASTS AND EVOLUTION OF THIS SYSTEM.  
 
- CORRESPONDING RAIN AND TEMPERATURE FORECASTS FOR THE LOCAL AREA  
ARE SUBJECT TO CHANGES LATER IN THE WEEK AND HIGHLY DEPENDENT ON  
THE TROPICS.  
 
 
   
DISCUSSION  
 
ISSUED AT 217 PM CDT TUE JUL 21 2026  
 
NO MAJOR CHANGES TO THE FORECAST... THE MAIN WEATHER CONCERNS ARE  
DANGEROUSLY HOT CONDITIONS AS WE CONTINUE TO MONITOR THE WESTWARD  
PROGRESS OF TROPICAL STORM BERTHA OVER THE NORTHERN GULF.  
 
NOW THROUGH WEDNESDAY: A MID TO UPPER LEVEL RIDGE CENTERED OVER  
THE ROCKIES CONTINUES TO DOMINATE WEATHER CONDITIONS ACROSS THE  
REGION BY PROVIDING STRONG SUBSIDENCE AND DRY AIR ACROSS THE AREA.  
AS BERTHA MOVES INTO THE NORTHWESTERN GULF, EVEN HOTTER  
CONDITIONS WILL BE IN PLACE BY WEDNESDAY, WITH HIGHS MOSTLY IN THE  
TRIPLE DIGITS. THE FIRST 100-DEGREE DAY MAY OCCUR ON WEDNESDAY IN  
SOME LOCATIONS. WITH INCREASING GULF MOISTURE, EXPECT DANGEROUS  
HEAT INDEX VALUES IN THE 108 TO 115F RANGE. A HEAT ADVISORY  
REMAINS IN EFFECT FOR ALL OF SOUTHEAST TX THROUGH 8 PM THIS  
EVENING. AN EXTREME HEAT WARNING HAS BEEN ISSUED FOR ALL OF  
SOUTHEAST TEXAS ON WEDNESDAY FROM 11 AM THROUGH 8 PM. REMEMBER,  
HEAT-RELATED ILLNESSES INCREASE SIGNIFICANTLY DURING EXTREME HEAT  
AND HIGH HUMIDITY EVENTS. PLEASE, STAY COOL, HYDRATED AND  
INFORMED.  
 
WEDNESDAY NIGHT INTO FRIDAY... WEATHER CONDITIONS WILL BE MAINLY  
INFLUENCED BY THE EVENTUAL TRACK AND INTENSITY OF TROPICAL STORM  
BERTHA. DRY AIR ENTRAINMENT AND INCREASED WIND SHEAR WILL CONTINUE  
TO PLAY A BIG ROLE IN ITS DEVELOPMENT ONCE IT MOVES NEAR THE  
LOUISIANA COAST AND HEADS WESTWARD TOWARD THE TX COAST. CURRENT  
OBSERVATIONS AND FORECASTS SHOW THE HEAVIEST PRECIPITATION AND  
STRONGEST WINDS FOR THIS SYSTEM ARE LOCATED ON THE SOUTH SIDE OF  
THIS ASYMMETRICAL STORM. THEREFORE, NO SIGNIFICANT IMPACTS ARE  
ANTICIPATED FOR SOUTHEAST TX AT THIS TIME. ISOLATED TO SCATTERED  
SHOWERS AND THUNDERSTORMS ARE POSSIBLE, WITH THE BEST CHANCES OVER  
THE COASTAL COUNTIES AND COASTAL WATERS. PLEASE CONTINUE TO  
MONITOR FOR FORECAST UPDATES AS BERTHA EVOLVES OVER THE NORTHERN  
GULF. SEE THE TROPICAL SECTION BELOW FOR MORE DETAILS ON BERTHA.  
 
SATURDAY THROUGH EARLY NEXT WEEK... DEPENDING ON THE  
TRACK/INTENSITY OF BERTHA, A FEW SHOWERS/STORMS WILL BE POSSIBLE  
ON SATURDAY. OTHERWISE, THE MID TO UPPER LEVEL RIDGE RE-  
ESTABLISHES OVER THE CENTRAL CONUS THROUGH THE WEEKEND, LEADING  
AGAIN TO DRIER AND HOTTER CONDITIONS. HEAT HEADLINES MAY BE NEEDED  
LATE THIS WEEKEND INTO EARLY NEXT WEEK AS HEAT INDICES RISE INTO  
THE 105-108 DEGF RANGE.  
 
JM  
 
 
   
AVIATION  
 
(00Z TAF ISSUANCE)  
ISSUED AT 607 PM CDT TUE JUL 21 2026  
 
MAINLY VFR CONDITIONS EXPECTED THROUGHOUT THE TAF PERIOD. WINDS  
WILL BE LIGHT AND VRB THROUGH EARLY WED, TURNING W TO NW DURING  
THE MID MORNING HOURS. WINDS WILL BE LIGHT AND VRB AGAIN WED  
EVENING. THERE IS SOME UNCERTAINTY WITH RESPECT TO RAIN CHANCES  
ON WED, WILL NOT ADD THE MENTION OF SH/TS FOR THIS TAF ISSUANCE  
AND WILL RE-EVALUATE FOR THE 06Z ISSUANCE.  
 
COTTO  
 
 
   
MARINE  
 
ISSUED AT 217 PM CDT TUE JUL 21 2026  
 
LIGHT TO OCCASIONALLY MODERATE WEST TO SOUTHWEST WINDS AND LOW  
SEAS WILL CONTINUE ACROSS THE UPPER TX COAST THROUGH AT LEAST LATE  
WEDNESDAY. MARINERS SHOULD CONTINUE TO MONITOR WEATHER  
CONDITIONS, ESPECIALLY THURSDAY AND FRIDAY AS TROPICAL STORM  
BERTHA MOVES WESTWARD ALONG THE NORTHERN GULF. THERE STILL REMAINS  
HIGH UNCERTAINTY IN THE FORECAST TRACK AND INTENSITY OF BERTHA.  
HOWEVER, BERTHA IS EXPECTED TO WEAKEN BACK TO A DEPRESSION BEFORE  
IT REACHES OUR COASTAL WATERS. WHILE FORECAST CONFIDENCE REMAINS  
LOW GIVEN THIS UNCERTAINTY, SIGNIFICANT IMPACTS ARE NOT  
ANTICIPATED ACROSS OUR COASTAL WATERS. HOWEVER, SMALL CRAFT  
ADVISORIES COULD POTENTIALLY BE ISSUED FOR ELEVATED WINDS AND SEAS  
UP TO 6 FT.  
 
JM  
 
 
   
TROPICAL  
 
ISSUED AT 217 PM CDT TUE JUL 21 2026  
 
THE NATIONAL HURRICANE CENTER CONTINUES TO TRACK TROPICAL STORM  
BERTHA, CURRENTLY CENTERED OFF THE FLORIDA PANHANDLE COAST. IT IS  
SLOWLY MOVED NNW TO NW TODAY AT AROUND 3-5MPH, BUT A BUILDING HIGH  
PRESSURE TO THE NORTH IS EXPECTED TO FORCE BERTHA ON A MORE WESTWARD  
TRACK LATER TODAY INTO WEDNESDAY MORNING. BERTHA HAS STRENGTHENED  
THROUGH THE DAY TODAY WITH MAXIMUM SUSTAINED WINDS OF 60 MPH AS  
OF THE 1PM CDT UPDATE. HOWEVER, STRONG NORTHERLY SHEAR HAS  
DISPLACED MOST OF THE THUNDERSTORMS AND WINDS TO BE LOCATED ON THE  
SOUTH SIDE OF THE STORM. ENVIRONMENTAL CONDITIONS CONTINUE TO  
LOOK UNFAVORABLE FOR FUTURE STRENGTHENING/ORGANIZATION AS BERTHA  
DEALS WITH THE HIGH WIND SHEAR, INCREASING SUBSIDENCE FROM THE  
BUILDING HIGH PRESSURE, AND DEALS WITH LAND INTERACTION ALONG THE  
CENTRAL GULF COAST OVER THE NEXT FEW DAYS. THE CURRENT FORECAST  
HAS BERTHA APPROACHING THE UPPER TEXAS COAST AS A WEAK TROPICAL  
DEPRESSION LATE THURSDAY INTO FRIDAY MORNING - IF IT SURVIVES.  
 
WE ARE NOT ANTICIPATING SIGNIFICANT IMPACTS TO SOUTHEAST TEXAS FROM  
TROPICAL STORM BERTHA. THE LOP-SIDED NATURE OF THE SHOWERS AND  
THUNDERSTORMS IS EXPECTED TO KEEP THE BULK OF THE RAINFALL OFFSHORE.  
SOME SHOWER AND THUNDERSTORMS COULD BE POSSIBLE ALONG THE COAST  
THURSDAY INTO FRIDAY AS THE SYSTEM APPROACHES FROM THE EAST, BUT NOT  
ANTICIPATING ANY SIGNIFICANT RAINFALL TOTALS. NBM SHOWS ABOUT A 10%  
CHANCE OF RAINFALL GREATER THAN 1" NEAR THE BARRIER ISLANDS, BUT  
OTHERWISE IS <5% ACROSS INLAND PORTIONS OF THE REGION. THE 90TH  
PERCENTILE RAINFALL TOTALS (WHICH IS THE REASONABLE WORST CASE  
SCENARIO) AROUND 0.5-0.8" SOUTH OF I-10. GUSTY WINDS WILL BE  
POSSIBLE OVER THE COASTAL WATERS AND ALONG THE IMMEDIATE COAST  
THURSDAY INTO FRIDAY, BUT CHANCE FOR TROPICAL STORM FORCE WINDS  
INLAND IS <5% AT THIS TIME. AND NO SIGNIFICANT COASTAL FLOOD IMPACTS  
ARE EXPECTED AT THIS TIME WITH FORECASTED HIGH TIDES AROUND 2-2.5FT  
ABOVE MLLW - WE TYPICALLY START TO SEE MINOR COASTAL FLOODING AROUND  
3.5FT. THERE WILL LIKELY BE AN INCREASED RISK OF RIP CURRENTS ALONG  
AREA BEACHES.  
 
PLEASE CONTINUE TO MONITOR THE LATEST FORECAST ON BERTHA AT  
WWW.HURRICANES.GOV.  
 
FOWLER  
 
 
   
PRELIMINARY POINT TEMPS/POPS  
 
COLLEGE STATION (CLL) 79 101 81 97 / 0 10 10 0  
HOUSTON (IAH) 80 103 82 99 / 0 10 10 10  
GALVESTON (GLS) 81 96 83 92 / 0 10 30 30  
 
 
   
HGX WATCHES/WARNINGS/ADVISORIES  
 
TX...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR TXZ163-164-176>179-  
195>200-210>214-226-227-235>238-300-313-335>338-436>439.  
 
EXTREME HEAT WARNING FROM 11 AM TO 8 PM CDT WEDNESDAY FOR TXZ163-  
164-176>179-195>200-210>214-226-227-235>238-300-313-335>338-  
436>439.  
 
GM...NONE.  
 
 
 
 
DISCUSSION...JM  
AVIATION...COTTO  
MARINE...JM  
TROPICAL...FOWLER  
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