textproduct: Houston/Galveston

KEY MESSAGES

- A stalled boundary and deep tropical moisture will lead to scattered to widespread showers and thunderstorms on Monday. Locally heavy rainfall with a Slight Risk (level 2 of 4) of Excessive Rainfall across most of SE Texas.

- Additional showers and thunderstorms will be possible on Tuesday. Greatest chances of locally heavy rainfall will be in the Brazos Valley, but isolated downpours will be possible across all of SE Texas. A slight risk (level 2 of 4) of excessive rainfall is in place for most of SE Texas on Tuesday as well.

- A gradual drying/warming trend should take shape heading into the second half of the work week.

DISCUSSION

Issued at 1133 PM CDT Sun Jul 12 2026

Deep tropical moisture continues to funnel into SE Texas as we kick off the work week. Satellite derived PWATs continue to show values around 2.1-2.2". The high moisture will work in concert with daytime heating and a slow moving boundary that is expected to stall as it moves south into SE Texas and will result in another day of scattered to widespread showers and thunderstorms. Greatest coverage of activity is expected during late morning through early evening hours. A lull in activity is anticipated for Monday night with another round of activity set for Tuesday.

High PWAT values and soundings point to an increasing potential for storms to produce heavy downpours that could result in minor urban ponding and minor flooding in areas with poor drainage. Forecast rainfall totals continue to fall into the 1-3" range. Given the saturated profile being observed with soundings and light steering winds, storms with heavier downpours could result in localized totals of up to 5" (especially if storms train over the same areas).

WPC has highlighted portions of Southeast Texas in their excessive rainfall outlook over the next few days.

- Monday, 6/13: A Slight Risk (level 2 of 4) for most of SE Texas, with the Matagorda Bay region in a Marginal Risk (level 1 of 4). - Tuesday, 6/14: A Slight Risk (level 2 of 4) for most of SE Texas, with southern portions of SE Texas in a Marginal Risk (level 1 of 4).

The latter part of the week will feature isolated activity to start, with a drying trend increasing towards the weekend.

The increase in cloud cover combine with increased rain chances will continue to keep temperatures on the cooler side during the afternoon. Highs will be in the upper 80s to low 90s through midweek. Expect heat and humidity to both increase going into the weekend as highs climb into the mid 90s by Friday and into the upper 90s this coming weekend. Heat indices are also expected to increase into the triple digits by the weekend.

Bailey

AVIATION

(12Z TAF Issuance) Issued at 625 AM CDT Mon Jul 13 2026

Some patchy MVFR cigs continue this morning near CLL to CXO, but these should quickly lift back to VFR in the next couple hours. SHRA and TSRA will develop near the coast in a few hours, pushing northward through the Houston metro terminals. Meanwhile, SHRA/TSRA will also be developing near the northern terminals (CLL, UTS, CXO), pushing southward. These clusters will likely collide somewhere near IAH/DWH and nearby sites. This will continue through the afternoon, slowly waning into the evening hours. Cigs will drop to MVFR/IFR north of the Houston metro, though IAH and DWH will be right on the edge of MVFR/VFR. The southern terminals will likely remain VFR. SHRA and possibly TSRA will redevelop late in the period into Tuesday morning near the coast, migrating inland again through the morning hours.

MARINE

Issued at 1133 PM CDT Sun Jul 12 2026

South to southeasterly winds around 10-15 knots and 2-4 ft seas will prevail through most of this week. A pattern of late night into early morning showers and thunderstorms is anticipated through at least midweek, some of which could produce heavy downpours and a reduction in visibilities. The majority of the activity is expected to move inland by the mid- morning hours each day, but isolated afternoon activity will still be possible over the coastal waters. Lower rainfall chances are expected to return by Thursday, but very isolated overnight activity will still be possible.

Bailey

PRELIMINARY POINT TEMPS/POPS

College Station (CLL) 88 73 84 72 / 70 70 70 30 Houston (IAH) 88 75 84 75 / 80 60 80 10 Galveston (GLS) 88 80 88 83 / 70 50 80 10

HGX WATCHES/WARNINGS/ADVISORIES

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