889
FXUS64 KHGX 152326
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
626 PM CDT Tue Sep 15 2026

...New AVIATION...

.KEY MESSAGES...

 - A Heat Advisory is in effect through this evening for much of
   the area.

 - Isolated showers and thunderstorms will continue through the
   week. Higher rain chances expected on Thursday as a surge of
   moisture moves through.

 - High temperatures in the upper to mid 90s expected through
   Wednesday.


&&

.DISCUSSION...
Issued at 1256 PM CDT Tue Sep 15 2026

The southwestern edge of a broad mid-level ridge anchored over
the Tennessee Valley will continue to provide subsidence over
Southeast Texas today and Wednesday, limiting the development of
showers and thunderstorms across the region. There will still be
sufficient low-level moisture (PWs of 1.7-2.0 inches) and
afternoon instability over areas south of the Brazos Valley and
Piney Woods region for a few showers and storms to develop during
the daytime hours, but coverage is expected to be mostly isolated.

The highs today and Wednesday will continue to range in the mid
to upper 90s for most inland areas and in the lower 90s for the
coastal locations. The Heat Advisory continues in effect through
this evening for heat indices peaking between 106-110 deg F. The
heat indices will range between 104-107 deg F on Wednesday.
Although it will be below Heat Advisory criteria, make sure to
continue to practice heat safety if you plan to work or spend
extended periods outdoors. Drink plenty of fluids, stay in an air-
conditioned room, stay out of the sun, and try to limit strenuous
activities to early morning or evening.

Chances for showers and thunderstorms will increase late
Wednesday night through Thursday as a surge of moisture from the
northern Gulf moves across the Upper Texas Coast, increasing PWs
to 2.0-2.3 inches. The latest NBM run is a bit wetter today
compared to yesterday`s run, but models continue to shift the mid-
level ridge westward into the Arkansas region on Thursday,
increasing our mid-level heights from 594 dam to 596-598 dam.
Thus, coverage of showers and thunderstorms will likely depend on
whether the moisture and instability can overcome the increased
subsidence. For this issuance, I have included 45-70% PoPs for
areas near and south of I-10 and 20-35% PoPs for the Brazos Valley
and Piney Woods. If subsidence cannot be surpassed, then we will
likely see lower chances inland with most storms staying generally
over the coastal locations and Gulf waters where the highest
moisture amounts and least influence of the ridge is. As far as
temperatures, the increased cloud coverage and rainfall will help
bring the highs back down to the lower to mid 90s on Thursday.

Drier air will move in from the northern Gulf on Friday,
decreasing our rain chances to mostly isolated activity near and
south of I-10. This trend is expected to continue through the
upcoming weekend.

&&

.AVIATION...
(00Z TAF Issuance)
Issued at 625 PM CDT Tue Sep 15 2026

Winds will become light this evening with cloud decks lowering to
around 1500-2000ft overnight. Could see some brief instances of
MVFR FLs from patchy fog and CIGs, mainly north of I-10 during the
early morning hours of Wednesday. CIGs/Fog should clear by the
late morning. Isolated showers and perhaps a few storms could
develop during the daytime on Wednesday, though coverage is still
anticipated to be fairly sparse. Best chances for rain will be
along the sea breeze during the mid/late afternoon. Any inland
convection that does develop should tapper off into Wednesday
evening.

03

&&

.MARINE...
Issued at 1256 PM CDT Tue Sep 15 2026

Light onshore winds and seas of 2 to 3 feet are expected today
and tonight. Winds will become easterly and increase to around 15
kts on Wednesday and 15-20 kts on Thursday. As winds strengthen,
seas will rise to 4 to 6 feet by Thursday. Winds relax and seas
gradually subside on Friday. Light onshore winds are expected to
return during the weekend.

Isolated showers and storms will persist daily, except on
Thursday, when scattered to numerous showers and storms are
expected as a surge of moisture moves in from the northern Gulf.
Stronger winds and higher waves are possible in and near strong
storms, along with frequent lightning.

Cotto

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)  76  98  77  96 /   0  10   0  20
Houston (IAH)  79  95  79  93 /   0  20  20  50
Galveston (GLS)  84  91  83  91 /   0  20  60  70

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...Heat Advisory until 7 PM CDT this evening for TXZ163-164-176>179-
     195>200-210>213-226-227-235>238-313-335-338.

GM...None.
&&

$$

DISCUSSION...Cotto
AVIATION...03
MARINE...Cotto