textproduct: Houston/Galveston

KEY MESSAGES

- Heat Advisory now in effect through Tuesday evening. - Very hot conditions along with a risk of an isolated thunderstorm continues through Wednesday. - Chance of showers and thunderstorms increases later in the week as the heat eases somewhat.

DISCUSSION

Issued at 113 PM CDT Mon Aug 24 2026

Upper-level ridge centered over West Texas, remains strong, resulting in another hot day. Currently monitoring a few disturbances moving around the eastern and southeastern edge of the high pressure. While most of this energy should stay to our east, over Louisiana, an increase in mid to high clouds is possible late tonight and Tuesday, which could keep temperatures just slightly lower. Even with afternoon surface dewpoints dropping slightly as drier air mixes down, peak heat index values on Tuesday will remain right around advisory levels. Highs will still reach the low 100s in some spots, with heat index values up to 109F. The heat "strengthens" again on Wednesday, bringing back temperatures in the triple digits across most inland areas. Albeit heat indices on Tuesday will be close to threshold, we've decided to extend the Heat Advisory through Tuesday evening to maintain clear heat messaging, with further extensions likely needed through midweek.

Rain chances remain generally low through midweek due to the strong sinking air, but afternoon shower or storm chances will begin to pick up toward the end of the week. As the ridge aloft shifts back to the west Thursday and Friday, more disturbances/vorticity maxes aloft will pass overhead. The combination of this weak energy aloft and warm, humid surface winds will be enough to trigger scattered afternoon showers and storms Thursday through the weekend. Rain chances have been kept in the 20 to 50 percent range, mainly driven by peak daytime heating and tapering off around sunset.

Temperatures toward the end of the week are progged to be slightly cooler thanks to increased cloud cover, and better rain chances. Highs will generally ease back into the mid 90s, giving most areas a break from the triple digit heat.

JM

AVIATION

(00Z TAF Issuance) Issued at 622 PM CDT Mon Aug 24 2026

Mid-upper level cloud debris from precipitation over portions of Louisiana will be rotating southwestward around the periphery of the ridge and into SE TX later this evening and overnight. Like previous nights, we cannot completely rule out some MVFR cigs/vis west and south of the metro area in the 10-14z timeframe. Some additional weak upper level disturbances riding down the northerly flow aloft will bring some isolated shra/tstm activity well to our e/ne on Tue, but we should still see some associated SCT/BKN clouds ~15kft. Light winds and VFR conditions should prevail. 47

MARINE

Issued at 113 PM CDT Mon Aug 24 2026

Benign weather conditions continue with south to southwest winds and seas in the 1 to 3 ft range through the weekend. Expect winds shifting to the southwest and west late at night and in the mornings, transitioning generally to the south in the afternoon and evening with the seabreeze. Rain and storm chances (around 20 to 50 %) will be on the increase Thursday into the weekend with the highest chances on Friday.

JM

PRELIMINARY POINT TEMPS/POPS

College Station (CLL) 77 101 78 102 / 0 0 0 10 Houston (IAH) 80 100 80 102 / 0 10 0 0 Galveston (GLS) 84 91 84 94 / 0 10 0 0

HGX WATCHES/WARNINGS/ADVISORIES

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

GM...None.