textproduct: Houston/Galveston

KEY MESSAGES

- Hot and dry conditions to prevail.

- Heat will be hazardous and near advisory critieria through early next week. Regardless of whether an advisory is in effect on any given day, heat precautions/messaging remain the same for those with plans or working outdoors.

- Guidance hinting at possible disturbance that could bring a chance of a few showers or thunderstorms Friday evening. Chance of rain is considered low at this time.

DISCUSSION

Issued at 1139 PM CDT Tue Aug 18 2026

A mid/upper, zonally elongated ridge centered over Texas has begun its westward drift and is amplifying as it does so. The primary impact this will have on the Wednesday atmosphere is a gradual shallowing of LL onshore flow. Tuesday featured deeper onshore flow (sfc to at least 500 MB), allowing for more cumulus and even a few isolated showers/storms on the sea breeze boundary. But we expect the mid-levels (~500MB) to shift to a more northerly trajectory later on Wednesday, which would have a tendency to lessen cumulus and decrease (though perhaps not totally eliminate) the chance of isolated sea breeze showers and storms. The high should amplify further, deepending the northerly flow aloft down to 850MB and limiting onshore flow to near the sfc. This will support an increasingly dry profile, allowing for lower dew points to mix down to the surface. But on the flip side, drier air along with less cumulus and stronger ridging will likely give temperatures a boost, with most inland areas expected to rise above 100 degrees Thursday through the weekend. Despite the potential for less humidity, actual temperatures could approach Heat Advisory criteria (actual temp 103+, heat index 108+) in some areas. One little wild card in the forecast entails vort maxes embedded in the northerly flow aloft that could provide enough lift for some shower and thunderstorm activity by the end of the week / weekend. Some of the guidance is picking up on a potential disturbance Friday evening. So we can't totally rule out this pattern producing isolated showers/storms despite the overall dry and hot signal.

The dry and hot pattern is expected to continue into next week. So brace yourselves for continued hazardous heat. August is gonna August.

Self

AVIATION

(06Z TAF) Issued at 1120 PM CDT Tue Aug 18 2026

VFR conditions prevail, with SSW winds decreasing into the overnight period. Winds take on a more WSW direction early tomorrow morning. For the past several days, there has been patchy fog/lower CIGs in the early morning hours around sunrise. Guidance has been backing off with any signal for CIG/VIS concerns. Another round of patchy fog and lower cigs is possible, however, there is a low chance that CIG/VIS reaches MVFR criteria-- cloud decks will be more "FEW" and "SCT" in nature, and any fog that develops will be patchy. Tomorrow, winds pick up in the afternoon and veer to the S. Gusts of 15-20 kts are possible late tomorrow afternoon. As for rain, the chances for any precip remains low, though we can't rule out a stray shower near the coast.

MLG

MARINE

Issued at 1120 PM CDT Tue Aug 18 2026

Light to moderate south to southwest winds are expected through early next week. Winds could gust up to 20 knots during the late afternoon and evening in the bays, and overnight into the early morning hours in the Gulf. Seas in the open Gulf are expected to average 2-4 feet

PRELIMINARY POINT TEMPS/POPS

College Station (CLL) 100 79 100 77 / 0 0 0 0 Houston (IAH) 99 80 99 78 / 20 20 0 0 Galveston (GLS) 93 84 92 84 / 10 0 0 0

HGX WATCHES/WARNINGS/ADVISORIES

TX...None. GM...None.