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 activity near the Piney Woods Friday evening.

- No substantial changes to the weather pattern through most of next week...so the August heat continues will mainly dry conditions.

DISCUSSION

Issued at 100 PM CDT Wed Aug 19 2026

Forecast looks to be one of mostly persistence for the next 7-10 days with the August heat continuing. Mid-upper ridging centered around the Four Corners region will slowly expand further esewd into the Southern Plains and Texas into the weekend and early next week keeping things hot and mainly dry. Until further notice, daytime highs will be in the 99-102F range inland and lower 90s at the beaches. Not a whole lot of relief is expected at night with lows in the upper 70s to mid 80s. Guidance is indicating a slight uptick in low level moisture Thursday and Friday and dewpoints might not be as prone to mix out quite as much, or as early, as they have in previous days. As such, higher heat indices are anticipated and have gone ahead and issued a Heat Advisory for Thursday & Friday...then re-evaluate things for possible extensions into the weekend. Peak heat index readings should generally be between 106-110F.

In terms of rainfall, the vast majority of the region should remain dry. Cannot rule out an isolated short-lived shower or two, but with one exception, chances are probably low enough to exclude the mention. That one exception (and probably best possibility in the next week) might be around the Piney Woods region Friday evening as some upper impulses in the N/NE flow aloft sag closer to the area and potentially generate some scattered storms (assuming subsidence can be overcome). Any lingering outflows on Saturday may assist in some isolated activity. There continues to be a mix of guidance showing that possibility, while others aren't as bullish. 47

AVIATION

(18Z TAF Issuance) Issued at 100 PM CDT Wed Aug 19 2026

For the 19/18Z TAF update, high pressure continues to exert its primary influence over the airspace. VFR vis/cigs are likely as a result through most of the period with a few MVFR exceptions. A low chance of inland MVFR cigs is still expected by 20/09Z-15Z as southerly to southwesterly winds slacken to near 5 kts. By 20/15Z through the end of the period, southerly winds will gradually regain speeds near 10 kts for most if not all terminals.

Cassel

MARINE

Issued at 100 PM CDT Wed Aug 19 2026

Southwest to south winds 10-15 knots will persist, with some intermittent higher gusts in the bays in the afternoon/evening hours and in the open Gulf waters at night. Seas should be in the 2 to 3 foot range through the weekend. 47

PRELIMINARY POINT TEMPS/POPS

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