textproduct: Houston/Galveston

KEY MESSAGES

- Scattered, diurnally driven showers and thunderstorms will remain in the forecast for the next several days.

- Diurnal = Afternoon showers/storms inland & overnight/morning showers/storms over the Gulf and potentially at the coast.

- High temperatures will generally be in the mid / upper 90s inland and the upper 80s to lower 90s along the coast. Near Heat Advisory criteria in our western (especially southwestern zones).

DISCUSSION

Issued at 1205 PM CDT Fri Sep 11 2026

There are some subtle differences between today's atmosphere and yesterday's atmosphere. At first glance, it looks the same. We still have our broad, discombobulated disturbance stretching from the Texas Coast to the Florida Panhandle, w/ 2"+ PWATs reigning supreme over most of the CWA. However, the disturbance has basically split into two separate ML vort maxes. One is situated near the FL Panhandle while the other one lurks off the Texas Coast. Though PWATs are high across our region, the ML (700-500MB) offshore disturbance appears to be translating somewhat down to the lower levels and redirecting moisture transport at least down to 850 MB. Yesterday, our 850MB moisture transport showed a clear vector pointing from the Gulf, indicating moisture pushing into southeast Texas. But today, those vectors are pointing west. So perhaps the CAMs aren't THAT crazy in thinking that there won't be much afternoon activity on the radar. But considering the PWATs, diurnal/mesoscale forcing, and the recent lackluster CAM performance, we are gonna hedge with 40-60 PoPs in our southeastern-most areas and 15-30 PoPs most elsewhere. Highs are expected to be 90s for most areas today.

A mid/upper SW CONUS ridge will push eastward, moving over the Lone Star State this weekend. This will make the atmosphere more suppressive but shouldn't eliminate shower/thunderstorm chances, especially in our southern and coastal counties. Temperatures are looking a little hotter, w/ heat index values getting suspiciously close to advisory criteria in our western counties and possible in our urban areas as well. For now, we are holding off on a heat advisory since dew points are expected to sufficiently mix downward. But it's something to keep an eye on.

The ridge pushes farther east next week, resulting in a deep, onshore LL flow regime. This pattern will tend to keep PWATs elevated (or at least a little above normal). Diurnally driven forces could easily suffice for at least isolated daily convection. But there may also be subtle disturbance embedded in the LL/ML flow (sfc-500MB) that could occasionally add lift and enhance diurnal convection this week. One may hear "LL disturbances coming from the Gulf" and wonder if there are tropical shenanigans afoot. At this time, there are not strong signals for development. The National Hurricane Center is not expecting any tropical development over the next 7 days. But given the time of year, it's always worth keeping daily tabs on the tropics just in case. Tis the season!

Self

AVIATION

(00Z TAF Issuance) Issued at 602 PM CDT Fri Sep 11 2026

Showers/storms should diminish over the next hour or two as daytime heating ceases. Winds relax and become light this evening. Cloud decks form around 1500-2000ft overnight, and could briefly fill in to produce MVFR CIGS early Saturday morning (potentially to IFR FLs in spots). Isolated patchy fog will also be possible in spots during the early morning, mainly in fog prone locations like KCXO. CIGs/Fog should clear around or by the late morning hours. Showers are also expected to develop over the coast Saturday morning. Convection could slowly shift inland during the afternoon, though overall rain chances/coverage are expected to be lower due to the building ridge aloft. Any convection that does develop should tapper off into Saturday evening.

03

MARINE

Issued at 1205 PM CDT Fri Sep 11 2026

Generally light to moderate onshore flow, 2-4 ft Gulf seas, and a daily risk of showers and thunderstorms will continue through the next several days. Winds offshore could be gusty at times overnight and into the morning hours, possibly gusting over 20 knots at times. The best chance of showers and thunderstorms will occur during the overnight and morning hours offshore, and during the late morning and early afternoon hours in the bays. Locally strong winds and a waterspout or two cannot be ruled out.

Some of the guidance is suggesting a long easterly fetch developing during the second half of next week. This could result in an increase in seas. For now, we are showing mostly 3-5 ft Gulf seas by week's end.

Self

PRELIMINARY POINT TEMPS/POPS

College Station (CLL) 77 99 76 98 / 10 0 0 10 Houston (IAH) 78 96 78 94 / 0 20 0 30 Galveston (GLS) 84 91 84 91 / 20 20 10 20

HGX WATCHES/WARNINGS/ADVISORIES

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