790
FXUS64 KHGX 271117
AFDHGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
617 AM CDT SUN SEP 27 2026
..NEW AVIATION
KEY MESSAGES
- ANOTHER HOT DAY TODAY WITH A GRADUAL INCREASE IN HUMIDITY
THROUGHOUT THE DAY.
- INCREASING RAIN AND STORM CHANCES WITH THE POTENTIAL OF HEAVY
RAINFALL, PEAKING FROM WEDNESDAY INTO THE WEEKEND.
DISCUSSION
ISSUED AT 1116 PM CDT SAT SEP 26 2026
THE MID TO UPPER LEVEL RIDGE CONTINUES TO WEAKEN AND MOVE OUT OF THE
REGION TODAY, SO ANOTHER RELATIVELY DRY AND HOT DAY IS ANTICIPATED
TODAY (SUNDAY). WITH SURFACE WINDS TRANSITIONING TO THE SOUTHEAST,
EXPECT A GRADUAL INCREASE IN LOW LVL MOISTURE THROUGH THE DAY. IN
OTHER WORDS, TODAY IT WILL FEEL MORE HUMID THAN THE PAST COUPLE OF
DAYS. WITH INCREASING WAA FROM THE GULF, AND PASSING WEAK IMPULSES
OF ENERGY ALOFT, HAVE SLIGHT RAIN AND STORM CHANCES, MOSTLY ALONG
THE COAST AND COASTAL WATERS TODAY. HOT WEATHER WITH TEMPERATURES 5
TO 10 DEGREES ABOVE NORMAL ARE EXPECTED MONDAY AND TUESDAY. AS A FEW
SUBTLE VORTICITY MAXIMA REMAIN OVER THE REGION ALOFT, COMBINED WITH
DAYTIME HEATING AND SEABREEZE BOUNDARIES, A FEW RAIN/STORM CHANCES
WILL BE POSSIBLE. BETTER CHANCES ALONG THE COAST.
A WETTER PATTERN IS ANTICIPATED FOR THE SECOND HALF OF THE WEEK AS
MOISTURE INCREASES AHEAD OF AN UPPER LVL TROUGH AND ITS ASSOCIATED
FRONTAL BOUNDARY. THE UPPER LEVEL TROUGH IS CURRENTLY OFF THE
PACIFIC COAST AND IS FORECAST TO MOVE EAST/INLAND ALONG THE WEST
COAST LATER TODAY. AS THE SYSTEM MOVES ACROSS THE SOUTHERN
ROCKIES/SOUTHWESTERN CONUS, IT WILL ALSO INTERACT WITH THE REMNANTS
OF POLO, LIKELY PULLING DEEP PACIFIC TROPICAL MOISTURE INTO THE
REGION. LATEST GUIDANCE STILL FAVORS A SLOWER SYSTEM; HOWEVER,
DISCREPANCIES STILL REMAIN REGARDING ITS EVOLUTION AND STRENGTH AS
IT MOVES OVER TEXAS. CONFIDENCE ON RAINFALL TOTALS AND/OR THE
LOCATION OF HEAVIEST RAINFALL ACROSS SOUTHEAST TEXAS IS STILL LOW.
THE GFS CONTINUES TO BE THE FASTEST SOLUTION AND BRINGS SHOWERS
AND STORMS IN AS EARLY AS WEDNESDAY, PEAKING ON THURSDAY. THE
ECMWF AND ITS ENSEMBLES KEEP MOST OF THE ACTIVITY TO OUR WEST, BUT
COINCIDE WITH THE GFS REGARDING HIGH QPF ON THURSDAY. WHAT WE
KNOW IS THAT DEEP TROPICAL PACIFIC MOISTURE FROM THE TROUGH AND
POLO, COMBINED WITH SOUTHEASTERLY SURFACE WINDS BRINGING MORE GULF
MOISTURE INLAND WILL RESULT IN PWAT VALUES IN THE 2.0 - 2.3 INCH
RANGE. THESE PWAT VALUES ARE IN THE 90TH-97.5TH PERCENTILE OF
CLIMATOLOGY FOR NAEFS, GEFS, AND ENS, WITH THE HIGHEST PERCENTILES
NEAR/AROUND OUR WESTERN COUNTIES. THIS IS A PERIOD TO KEEP AN EYE
ON; WHEREVER THE BEST DYNAMICS MEET SUFFICIENT MOISTURE, HEAVY
RAINFALL IS LIKELY. WPC HAS HIGHLIGHTED THIS RISK OF EXCESSIVE
RAINFALL IN THEIR DAY 4 (WEDNESDAY) OUTLOOK. GIVEN THAT MODELS
SHOW A SLOW- MOVING TROUGH, RAIN AND STORM CHANCES PEAK ON
THURSDAY AND PERSIST THROUGH AT LEAST SATURDAY WITH AS THE FRONT
(FROPA) FINALLY ENTERS THE REGION. AS OF NOW, THE BRAZOS VALLEY
HAS THE HIGHEST PROBABILITY OF GETTING OVER AN INCH OF RAIN ON
WEDNESDAY (35 TO 45%), WHILE MOST OF SOUTHEAST TEXAS WILL HAVE
AROUND 60% OF PROBABILITY OF GETTING OVER AN INCH ON THURSDAY. AS
OF NOW, 1 TO 3 INCHES WILL BE POSSIBLE, BUT AGAIN, WILL CONTINUE
TO MONITOR TRENDS AS HIGHER OR LOWER TOTALS WILL BE POSSIBLE.
FINER DETAILS WILL BE PROVIDED AS THIS TROUGH PROGRESSES TODAY AND
MONDAY AND HI-RES GUIDANCE STARTS TO COME IN.
JM
AVIATION
(12Z TAF ISSUANCE)
ISSUED AT 615 AM CDT SUN SEP 27 2026
THERE ARE SOME ISO-SCT SHRA FROM THE GALVESTON BAY AREA SOUTHWARD
INTO THE COASTAL WATERS THAT'LL LIKELY LINGER INTO THE MID MORNING
HOURS. OTHERWISE, CONTINUED VFR WITH LIGHT WINDS THROUGH THE TAF
PERIOD. 47
MARINE
ISSUED AT 1116 PM CDT SAT SEP 26 2026
A FEW LIGHT SHOWERS OR STORMS WILL BE POSSIBLE THROUGH MID-LATE
MORNING, NEAR GALVESTON ISLAND AND BOLIVAR PENINSULA. OTHERWISE,
LIGHT EAST TO SOUTHEAST WINDS AND LOW SEAS WILL PREVAIL TODAY.
UNSETTLED WEATHER IS EXPECTED AS EARLY AS TUESDAY, PERSISTING INTO
THE UPCOMING WEEKEND AS A DISTURBANCE MOVES OVER THE PLAINS AND
PUSHES A FRONTAL BOUNDARY. LOOK FOR PERIODS OF RAIN AND
THUNDERSTORMS, PEAKING THURSDAY AND FRIDAY, ALONG WITH ELEVATED
WINDS AND BUILDING SEAS (UP TO 7-8FT). SMALL CRAFT ADVISORY WILL
LIKELY BE NEEDED AFTER MIDWEEK.
JM
PRELIMINARY POINT TEMPS/POPS
COLLEGE STATION (CLL) 97 73 96 72 / 0 0 0 0
HOUSTON (IAH) 94 76 94 76 / 10 0 10 0
GALVESTON (GLS) 88 82 88 82 / 20 0 20 0
HGX WATCHES/WARNINGS/ADVISORIES
TX...NONE.
GM...NONE.
DISCUSSION...JM
AVIATION...47
MARINE...JM
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