textproduct: Houston/Galveston

KEY MESSAGES

- Heat Advisory is in effect Thursday and Friday for heat index values peaking between 106-110F. The advisory may need to be extended into the weekend. - Rain chances will be very low through Friday, but might need to keep an eye out for some isolated-scattered thunderstorm activity near the Piney Woods Friday evening.

- Hot weather expected to continue through next week.

DISCUSSION

Issued at 1039 PM CDT Wed Aug 19 2026

The synoptic pattern through most, perhaps all, of the forecast period will feature a strong central / west CONUS ridge and an east CONUS trough. Our weather will be heavily influenced by the ridge, keeping conditions very hot and generally dry (key word "generally"...more on that below). Inland afternoon temperatures are expected to average around 100 degrees, with higher heat indices. The heat will be dangerous, especially for sensitive groups and for those doing outdoor work and activities. A Heat Advisory is in effect through Friday, and could be extended into the weekend in future updates.

But there continues to be a wild card in this forecast. Embedded in the northerly-ish mid/upper flow between the ridge and the trough will be little disturbances / vort maxes. These will occasionally add lift to the SE Texas atmosphere and could potentially spark off a few thunderstorms. The HRRR is under the impression that a disturbance over Kansas could hold together enough to bring a few showers/storms conspicuously close to our northern Piney Woods zones Thursday evening. But the most suspicious time period is late Friday afternoon and evening, when about half of the guidance throws a mid/upper disturbance in our direction, opening the door to convection that enters the CWA from the northeast. Southwest moving convection on a hot 100-degree day can be a signal for underestimated thunderstorms. I kept 20-30 PoPs in our northern and northeastern zones for late Friday afternoon and evening. I also decided to keep some low PoPs for Saturday as well.

This theme is expected to continue deep into next week. The signal for hot and dry weather remains strong. But we won't be able to totally write off the chance of an afternoon / evening thunderstorms due to the potential for additional mid/upper level disturbances.

Self

AVIATION

(06Z TAF Amendment) Issued at 1039 PM CDT Wed Aug 19 2026

For the 06Z update, VFR conditions prevail with winds out of the SSW. Winds weaken and turn more WSW during the overnight period, then once again increase and return to the SSW by tomorrow afternoon. Gusts of 15-20 kts are possible tomorrow afternoon and evening, similar to what has occurred for the last few days. Early tomorrow morning, inland sites may experience some brief MVFR CIGs. It is uncertain whether CIGs will fill in enough to qualify as MVFR, but given the similar atmospheric conditions to yesterday, it is not off the table to see some on and off ~BKN015 tomorrow morning between 09Z and 13Z. The forecast remains hot and dry, and VFR conditions are expected for the rest of the day tomorrow.

MLG

MARINE

Issued at 1039 PM CDT Wed Aug 19 2026

Light to moderate south to southwesterly flow and 2 to 3 foot seas should continue through at least early next week. Occasionally higher gusts to 20 knots are possible in the bays during the late afternoon, and over the Gulf during the overnight hours.

PRELIMINARY POINT TEMPS/POPS

College Station (CLL) 101 77 102 78 / 0 0 0 0 Houston (IAH) 100 79 100 80 / 10 0 0 0 Galveston (GLS) 92 84 91 83 / 0 0 0 0

HGX WATCHES/WARNINGS/ADVISORIES

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

GM...None.