452
FXUS64 KHGX 131934
AFDHGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
234 PM CDT THU AUG 13 2026
..NEW DISCUSSION, AVIATION, MARINE
KEY MESSAGES
- A BRIEF INCREASE IN GULF MOISTURE WILL BOOST RAIN CHANCES ON
FRIDAY AHEAD OF A DRIER PATTERN DEVELOPING THROUGH THE WEEKEND
INTO NEXT WEEK.
- ABOVE AVERAGE SUMMERTIME HEAT (UPPER 90S/LOWER 100S) WILL
PERSIST THROUGH MOST OF THE REST OF THE MONTH ACROSS SOUTHEAST
TEXAS.
- CUMULATIVE IMPACTS OF HEAT (AND HEAT STRESS) WILL REMAIN A
SIGNIFICANT RISK FACTOR, ESPECIALLY FOR HEAT-SENSITIVE
POPULATIONS.
DISCUSSION
ISSUED AT 151 PM CDT THU AUG 13 2026
AS OF 2 PM CDT, WATER VAPOR SATELLITE IMAGERY CLEARLY DEPICTS AN
UPPER-LEVEL AREA OF LOW PRESSURE ENTERING THE NORTHWESTERN STATES
OF MEXICO WITH AN ATTENDANT FETCH OF MOISTURE OFFSHORE. AS THE
CENTER OF THE AFOREMENTIONED CIRCULATION TRANSITS FURTHER INLAND,
NEARLY PARALLEL WITH THE RIO GRANDE, IT WILL ADVECT DEEPER GULF
MOISTURE ONSHORE (PWAT VALUES AT OR ABOVE 2 INCHES, NEAR 75TH-
PERCENTILE OF CLIMATOLOGY). THIS WILL CREATE A MORE AMPLE
ATMOSPHERIC ENVIRONMENT FOR CONVECTION TO TAP INTO, WITH MORE
EFFICIENT RAINFALL RATES CERTAINLY NOT OUT OF THE QUESTION THROUGH
FRIDAY AFTERNOON INTO THE EVENING. THAT SAID, THE NEXT 24 TO 36
HOURS ALSO REMAINS AS THE BEST WINDOW OF OPPORTUNITY FOR ANY
RAINFALL THROUGH THE NEXT SEVEN DAYS. IN SYNOPTIC-SCALE FLOW
ALOFT, SOUTHEAST TEXAS CURRENTLY REMAINS BETWEEN THE WESTERN
PERIPHERY OF RIDGING OVER THE EASTERN GULF COAST AND UPPER-LEVEL
TROUGHING OVER MEXICO. WINDS IN THE GRADIENT BETWEEN THESE
FEATURES TODAY CONTINUE TO TEMPORARILY PRECLUDE THE AREA FROM HEAT
INDICES WELL ABOVE 108F (AND SUBSEQUENT HEAT ADVISORY CRITERION
FOR NOW).
BY SATURDAY, THIS RIDGING WILL BUILD FURTHER ACROSS THE SOUTHERN
GREAT PLAINS, INTRODUCING A MORE SUBSIDENT CONVECTIVE ENVIRONMENT
AND LIGHTER WINDS THROUGH MOST OF THE REST OF THE FORECAST PERIOD.
THIS RIDGE WILL ALSO SUSTAIN IMPACTFUL HEAT WELL INTO NEXT WEEK,
WITH MULTIPLE PERIODS OF WIDESPREAD HEAT INDICES IN THE 105F-108F
RANGE. WITH LONG-RANGE GUIDANCE CONTINUING TO SUGGEST MULTIPLE
DAYS OF ABOVE AVERAGE HEAT (AVERAGE NEAR 96), CUMULATIVE HEAT
STRESS REMAINS A RISK TO HEALTH OUTDOORS AND PRECAUTIONS CAN BE
TAKEN TO REDUCE THE RISK OF HEAT ILLNESS. THESE PRECAUTIONS
INCLUDE AND ARE NOT LIMITED TO: REDUCING OR CHANGING TIME SPENT
OUTDOORS TO COOLER TIMES OF DAY, INCREASING TIME AND ACCESS TO
AIR-CONDITIONED SPACES, CHECKING ON HEAT-SENSITIVE POPULATIONS,
AND CHECKING THE CAR SEATS OF VEHICLES BEFORE DEPARTURE FOR THE
DAY.
CASSEL
AVIATION
(18Z TAF ISSUANCE)
ISSUED AT 151 PM CDT THU AUG 13 2026
OVERALL, VFR CONDITIONS PREVAIL THROUGH THE REST OF THE DAY. SSW
WINDS OF 7-12KTS AND GUSTS AROUND 20 KTS CONTINUE THIS AFTERNOON AND
EVENING. WINDS DECREASE OVERNIGHT, WHILE TURNING TO A MORE SSE
DIRECTION. AT KCXO TOMORROW MORNING, WINDS MAY CALM ENOUGH TO
INCREASE CHANCES FOR PATCHY FOG. EARLY TOMORROW MORNING, ANOTHER
MVFR DECK SETTLES INTO THE NORTHWEST PORTION OF THE AREA, MAINLY
EFFECTING KCLL FROM ABOUT 09-15 UTC. LATE TOMORROW MORNING, WINDS
AND GUSTS ARE EXPECTED TO PICK BACK UP. LOOKING AHEAD TO TOMORROW
AFTERNOON, A SURGE OF TROPICAL MOISTURE INCREASES CHANCES FOR
SHOWERS/THUNDERSTORMS ALONG THE SEABREEZE.
MLG
MARINE
ISSUED AT 151 PM CDT THU AUG 13 2026
SEAS WILL REMAIN AT 3 TO 5 FEET TODAY, KEEPING CAUTION FLAGS IN
EFFECT THROUGH THE REST OF TONIGHT. LATE FRIDAY MORNING THROUGH
THE REST OF THE DAY REMAINS AS THE BEST CHANCE OF RAIN OFFSHORE
FOR THE FORESEEABLE FUTURE AS A ROUND OF GULF MOISTURE PASSES
ONSHORE. HIGH PRESSURE WILL THEN BEGIN TO BUILD FURTHER ONSHORE,
ALLOWING WINDS TO SLACKEN AND SEAS TO CALM FURTHER TO 2 TO 3 FEET
THROUGH THE WEEKEND INTO NEXT WEEK.
CASSEL
PRELIMINARY POINT TEMPS/POPS
COLLEGE STATION (CLL) 76 97 77 98 / 0 20 0 0
HOUSTON (IAH) 79 95 80 97 / 0 30 0 0
GALVESTON (GLS) 84 90 84 90 / 10 20 0 0
HGX WATCHES/WARNINGS/ADVISORIES
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION THROUGH LATE TONIGHT FOR
GMZ330-335-350-355-370-375.
DISCUSSION...CASSEL
AVIATION...MLG
MARINE...CASSEL
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