textproduct: Houston/Galveston

KEY MESSAGES

- Scattered showers and thunderstorms today, with highest chances along the coast.

- Less humidity Friday and Saturday with no precipitation chances.

- Humidity returns Sunday along with daily diurnal storm chances into next week.

DISCUSSION

Issued at 1207 PM CDT Thu Sep 17 2026

The well-advertised tropical moisture plume has arrived and associated showers and thunderstorms are currently moving onshore. These should peak in coverage late this morning into afternoon, with highest chances along the coast and south of I-10. Heavy downpours are the main threat, so use caution if traveling. That all said, given the increased capping/subsidence with the strong upper ridge moving westward this afternoon, the more "scary" looking CAMs may not necessarily verify. In any case, storms will gradually taper off through the evening. The ridge will usher in drier air overnight into Friday. We will see a brief reprieve from the humidity with heat indicies staying below 100. With the dry air and capping from the ridge, precipitation is not expected anywhere, even along the coast. Similar conditions will prevail Saturday as the ridge remains in place between two troughs on either side of it.

The ridge will begin to slightly weaken Sunday and the higher humidities will return albeit slightly lower than values that lead to recent Heat Advisories. Nonetheless they will still generally range from 102-105F. Precipitation chances should remain minimal. This large-scale pattern will remain in place through much of next week, with no significant systems on the horizon. Except hot temperatures, humidity, and diurnal convection to persist each day.

AVIATION

(18Z TAF Issuance) Issued at 1207 PM CDT Thu Sep 17 2026

Isol convection continues to build south of the 1-10 corridor as the afternoon progresses. ENE winds also continue to increase with gusts between 15-20kts and the possibility to be stronger around convection. The timing and coverage will continued to be monitored, with amendments being made as needed, as convection spreads inland. Convection is anticipated to subside by the evening due to incoming dry air. As the evening arrives winds first shift to ESE before relaxing to LGT and VRB overnight. Outside of convection VFR conditions prevail across the area.

MARINE

Issued at 1207 PM CDT Thu Sep 17 2026

Easterly sustained winds near 20 kts will continue through around midnight tonight. They will remain breezy through Friday at 15-20 kts, before becoming light on Saturday and eventually veering to the southeast. Seas of 4 to 6 ft will continue through Friday morning before subsiding to 3 to 5 ft into Saturday morning and further subsiding to 2 to 3 ft thereafter. Showers and thunderstorms remain likely through today along the coast and over offshore waters. Drier air Friday into the weekend will significantly curtail any additional chances, though some will remain offshore.

PRELIMINARY POINT TEMPS/POPS

College Station (CLL) 74 97 71 97 / 0 0 0 0 Houston (IAH) 77 94 75 95 / 0 0 0 0 Galveston (GLS) 84 90 83 91 / 0 0 0 0

HGX WATCHES/WARNINGS/ADVISORIES

TX...None. GM...Small Craft Should Exercise Caution through late tonight for GMZ350-355-370-375.