textproduct: Houston/Galveston

KEY MESSAGES

- Dangerous heat building this week with temperatures in the upper 90s/100s and heat indices of 104-112F. Heat Advisories likely at times during the upcoming work week.

- Patchy fog possible during the early to mid-morning hours for at least the next few days.

DISCUSSION

Issued at 1122 PM CDT Sat Jul 25 2026

To give y'all an idea of what's up ahead over the next several days: today was the "coolest" day of the forecast period, and we had high temperatures in the low to mid 90s. The City of Houston has only had one day above 100 degrees so far this year...and we have pretty high confidence that we'll be adding onto that next week. The 596-598 dam mid-level high (AKA the heatdome) has nudged a bit eastward from yesterday and is now centered just east of the Four Corners. It will continue to drift eastward going into Sunday and early next week, which will pair with 850mb temperatures increasing to above the 90th percentile and occasionally approaching the 99th percentile for most of the work week. That means triple digit heat is on the horizon...and we haven't even discussed the humidity part of it yet.

South-southwesterly to southerly surface flow should keep dew points elevated (low to mid 70s) closer to the coast. Further inland, we should see dew points mixing down into the upper 60s to low 70s in the afternoons during the work week. The air temperatures will be high enough though that we'll still see heat indices peaking near or above the Heat Advisory threshold (greater than 108 degrees) at times next week. Decided to hold off on a Heat Advisory for Sunday since we won't see widespread locations reaching criteria...not entirely ruling out a few spots reaching criteria though. There won't be much relief overnight with low temperatures mainly in the upper 70s to low 80s. The atrocious humidity overnight will result in occasional rounds of patchy fog in the early to mid morning hours for at least the next few days. Sunday will feature a slight chance of rain even in the midst of increasing subsidence. It'll be a battle of increasing subsidence versus a team-up of daytime heating, the sea breeze, an embedded shortwave, and increased moisture just below the 75th percentile (~2.03"). Not quite as exciting as an endgame battle, but there's not much else to talk about other than the heat so we're watching with great interest! Destiny arrives all the same though, because most of us won't see a drop of rain over the next several days and will be left to deal with the sweltering heat.

PW values decrease again closer to the 10th percentile (~1.36") through at least midweek, so rain chances will be slim to none for most of the work week. Towards the end of the work week, the heatdome begins to retreat westward a bit which may open the door for some isolated convection...but we're keeping that potential on the low side for now. Continuing to look towards next weekend for a return of more sufficient rain chances. Ensemble guidance (both GEFS and the Euro) have decent agreement on a surface low developing near the Red River towards the end of the work week. This coincides with the heatdome retreating westward and an upper level trough drifting through the eastern CONUS. Does this bring a weak frontal boundary in the vicinity of our area along with increasing moisture? I can't say yes...but I also can't say no. After what looks to be multiple 100+ degree days in a row, I would gladly take some rain! Uncertainty is still fairly high with this, so we'll continue to monitor trends as the week progresses.

With heat indices expected to be near or above Heat Advisory criteria as early as Sunday, please keep heat safety at the top of your minds for any plans that you make (especially if outdoors). Know the signs of heat-related illnesses, stay hydrated (with water), take frequent breaks from the heat, wear loose/light-colored clothing and sunscreen, and ALWAYS ALWAYS ALWAYS LOOK before you LOCK your vehicle. Don't forget about your pets as well! If the ground is too hot for the palm of your hand, then it is too hot for their paws.

Batiste

AVIATION

(00Z TAF Issuance) Issued at 645 PM CDT Sat Jul 25 2026

VFR conditions will mostly prevail through tonight and Sunday. KCXO could see IFR fog around early morning, which dissipates by about 13Z. Current guidance suggests isolated sea breeze showers are possible, but confidence remains low so they were kept out of the TAFs.

JMG

MARINE

Issued at 1122 PM CDT Sat Jul 25 2026

A period of benign marine conditions continues with light to occasionally moderate southerly/southwesterly winds and 2-4 ft seas prevailing over the next several days.

Batiste

PRELIMINARY POINT TEMPS/POPS

College Station (CLL) 74 96 76 97 / 0 0 0 0 Houston (IAH) 77 97 78 99 / 10 20 20 0 Galveston (GLS) 83 91 83 92 / 0 20 0 0

HGX WATCHES/WARNINGS/ADVISORIES

TX...None. GM...None.