textproduct: Houston/Galveston

KEY MESSAGES

- Heat Advisory in effect for our southern counties (including the City of Houston) this afternoon. - Frontal boundary may bring isolated to widely scattered showers/ storms later today / this evening, though a morning shower is possible in our northern counties.

- Forecast has trended hotter for Sunday and especially Monday.

DISCUSSION

Issued at 1220 AM CDT Sat Aug 1 2026

As of 12AM CDT, there are few things that catch my eye as I write this AFD. Water vapor imagery is currently telling a story of a flow pattern in flux. The ridge that has dominated Texas weather over the last weak is shifting west, with the center of its ridge axis firmly over W CONUS. Meanwhile, a deep low over the Midwest is diving east to southeast, while its trailing cold front extends all the way down into SE Oklahoma and N Texas. The airmass behind the front is also of interest, featuring decreasing dew points and cooler temperatures. Me thinks the falling dew points are in SE TX's future....the cooler temps not so much.

The HRRR continues to insist on a band of showers that develops over our northern counties early this morning. The showers push southward, fizzling out before reaching the I-10 corridor. Some of the other CAMs suggest the presence of an isolated shower or two. There does appear to be plenty of dry air in the 900-700 MB zone. But ML water vapor imagery suggests there is slightly less ML dry air in our northern zones. So I kept some PoPs in the forecast north of I-10 this morning to give the HRRR a little weight in the forecast. We shall see...

This aforementioned front should continue its southward push, reaching our neck of the woods by later today or tonight. There's still some question regarding the timing of the front. Will the front be able to interact with peak daytime heating? Latest guidance suggest it won't arrive in SE TX until the evening, when daytime heating is being lost. Therefore, the chance of seeing showers/thunderstorms has decreased but has not been eliminated for later today. A veering wind profile ahead of the front will support a modest WAA regime when the air is already quite hot. Forecast peak heat indices from the I-10 counties to the coast are generally 107-110 degrees, warranting the issuance of a Heat Advisory from 1PM to 7PM CDT in our southern zones. There could be a sweet spot that's just inland enough to limit Gulf influence but also just coastal enough to limit mixing that manages to reach 111-112F.

Sunday may feature some showers and isolated storms near the coast and offshore in the morning. Otherwise, much drier air infiltrates the area in the front's wake. Mid/upper heights will be at their lowest on Sunday, generally supporting a cooler temperature profile. But drier air and the August sun should boost temperatures into the upper 90s to around 100 (low 90s coast). Inland dew points are expected to be well down into the 60s, which should keep heat indices below advisory criteria. The dry air may not make it to the coast. So if you're in a coastal county, you may remain in the humid soup. But on Monday, the ridge builds back into the region, warming the temperatures profile. With a similar dry LL regime remaining in place, Monday's actual temperatures cold get quite hot. Right now, we have high temperatures ~100 degrees across most inland areas. But this is technically a little "cooler" than most of the guidance. If forecast temperatures trend another 2-3 degree higher, then we could be approaching Heat Advisory criteria for actual temperatures (103+). The high heat may linger into Tuesday before temperatures attempt to modify down to normal by mid/late week.

Self

AVIATION

(00Z TAF Issuance) Issued at 657 PM CDT Fri Jul 31 2026

A weak cold front will attempt to move through the terminals Saturday afternoon, bringing rain and storm chances for most terminals. A few -SHRA are possible near KCLL and KUTS around 11Z- 13Z, with the best chances (20 - 35%) in the afternoon. Confidence in SHRA/TSRA for terminals from IAH coastward is low; therefore, have only included PROB30 from mid afternoon through early evening for this forecast package. Light to occasionally moderate WSW winds will prevail Saturday. Overall, expect SCT to BKN mid to high clouds, with FEW/SCT low clouds possible early Saturday. Outside of any TSRA, VFR conditions can be expected through the period.

JM

MARINE

Issued at 1136 PM CDT Fri Jul 31 2026

Southwest winds 10-15 knots should gradually increase to 15-20 knots later today into tonight. For Galveston Bay and our eastern Gulf zones, winds may gust to around 25 knots at times. Small vessels should exercise caution later today into tonight. A frontal boundary approaches the area this evening into tonight, possibly resulting in a few showers and thunderstorms tonight into Sunday morning. Westerly winds are expected on Sunday, followed by continued light to moderate south to southwest winds through much of the upcoming week. Winds may become more south-southeast late in the week. Seas should primarily be 2-3 feet, but could build to 4 feet (locally 5ft) Saturday night in our eastern Gulf zones.

PRELIMINARY POINT TEMPS/POPS

College Station (CLL) 99 77 97 75 / 0 0 40 10 Houston (IAH) 99 79 99 80 / 0 0 20 20 Galveston (GLS) 91 83 94 82 / 0 0 10 30

HGX WATCHES/WARNINGS/ADVISORIES

TX...Heat Advisory from 1 PM to 7 PM CDT Saturday for TXZ200-213-214- 226-227-235>238-300-313-335>338-436>439.

GM...None.