textproduct: Houston/Galveston

KEY MESSAGES

- Heat Advisory continues through Wednesday.

- Rain and storm chances increase slightly late Wednesday night and Thursday across the region.

- Low sea breeze storm chances continue through the weekend.

SHORT TERM

(This evening through Wednesday Night) Issued at 122 PM CDT Tue Aug 25 2026

Visible satellite imagery shows an expanding scattered cumulus field across southeast TX indicative of the low level moisture in place with some higher level cloud cover spreading in from the north. This is associated with some decaying convection around the eastern periphery of a stout mid level ridge over the Southern Plains. The rest of the afternoon will generally be precipitation free outside of an isolated (~10%) shower along the sea breeze. Temperatures will top out in the upper 90s to 102 inland with mid 90s along the coast and heat indices between 105-110 degrees.

The center of the mid level ridge will begin a slow transition westward over the next 48 hours with a weak disturbance evident in water vapor imagery over southwest Kansas expected to spread through the Southern Plains. This will likely result in another round of convection well to our northwest overnight tonight. This activity may be in the decaying phase again across our northern counties early Wednesday morning with additional cloud cover spreading into the Brazos Valley. Otherwise, Wednesday will be similar to today with highs near 100 inland and heat index values around 107-109 degrees. With northerly flow becoming a little more pronounced around the eastern periphery of the ridge, a weak front will begin to slide south across East Texas on Wednesday. This will allow moisture to pool across the Brazos Valley late Wednesday night where some low rain/storm chances will spread in from the north after midnight.

Dunn

LONG TERM

(Thursday through next Monday) Issued at 122 PM CDT Tue Aug 25 2026

The aforementioned frontal boundary will sag southward into southeast Texas on Thursday although it won't be cooler by any means. This will primarily be more of a wind shift although moisture pooling along the boundary will be the main focus for convective development in a weakly capped unstable afternoon environment. Scattered showers and a few storms are expected Thursday afternoon with coverage around 20-30%. Convective coverage may be a little more robust across southwest Louisiana during this time and we'll have to see if this manages to spread southwest late Thursday night into Friday particularly across the coastal waters. With the expected increase in cloud cover and potential for showers/storms, it's likely that we'll be able to forego an extension of the Heat Advisory for Thursday, but that temporarily relief will give way to more heat and humidity Friday through the weekend as mid level ridging again builds back to the east across the region. Highs will top out in the upper 90s each day through Sunday with heat indices between 105-108 degrees.

Diurnally driven storm chances will likely tick upward again early next week as a weak disturbance spreads across the northwest Gulf into Texas with a slight reduction in afternoon highs.

Dunn

AVIATION

(18Z TAF Issuance) Issued at 1215 PM CDT Tue Aug 25 2026

VFR conditions will prevail across southeast Texas today with partly cloudy skies and winds generally around 5 kts or less and variable. Some MVFR-level cloudiness is expected to develop overnight that could briefly constitute a ceiling, but most, if not all, sites are expected to remain VFR overnight into Wednesday morning. Light southerly winds are expected to shift to the southwest by around 15Z and increase to the 5-10 kt range.

McNeel

MARINE

Issued at 122 PM CDT Tue Aug 25 2026

Light southwest winds prevail across the coastal waters at this time with southerly winds 10-15 kt expected tonight. Wind direction will vary from southwest early in the day Wednesday and Thursday to southerly 10-15 kt in the afternoons. Isolated showers are expected this afternoon with storm chances increasing Thursday afternoon into Friday. Otherwise seas 1 to 3 feet can be expected with typical summertime diurnal wind direction changes through the weekend.

Dunn

PRELIMINARY POINT TEMPS/POPS

College Station (CLL) 77 101 78 101 / 0 0 20 30 Houston (IAH) 79 100 80 98 / 0 10 10 20 Galveston (GLS) 83 90 82 90 / 0 10 10 20

HGX WATCHES/WARNINGS/ADVISORIES

TX...Heat Advisory until 7 PM CDT Wednesday for TXZ163-164-176>179- 195>200-210>214-226-227-235>238-300-313-335>338-436>439.

GM...None.