textproduct: Houston/Galveston

KEY MESSAGES

- Band of showers and storms will move into the region late tonight and off to the east as the day progresses Wednesday. Some storms could be locally strong and also produce heavy downpours.

- Mariners should check the latest weather conditions and forecast before beginning or continuing their transits. Hazardous conditions are expected late tonight into Wednesday morning.

- Less active weather is anticipated for the remainder of the week.

DISCUSSION

Issued at 116 PM CDT Tue May 26 2026

Isolated to scattered showers and tstms will continue for the remainder of the afternoon. They should diminish around sunset with the loss of heating. But, later tonight we expect a band of showers and storms to approach the region from the west as the next weather system moves into the area.

In general, look for this band of storms to approach western parts of the CWA around midnight +/- a few hours, move across the I-45 corridor during the morning rush, then exit off to our east in the mid and late morning hours. PW's between 1.9-2.1" should pool along and ahead of this system. There appears to be enough instability to work with to see some healthy storms, and perhaps an embedded severe cell or two with any bowing segments. Overall, suspect this might be one of those systems where we see some 30-45mph gusts along, and just behind, the leading line of storms. Diffluent flow aloft should also allow for some heavy downpours in short time periods...the type we could see some brief 2-4"/hr rates that can produce street flooding. On average, we're looking for some widespread 1-2" accumulations with localized swaths of 3-5" possible in the more significant or regenerating cells. Coastal areas that saw the higher rain amounts last week will be prone to quicker runoff and flash flood threat.

Remainder of the week looks less active in terms of significant weather. as some subtle mid level ridging builds in from the west. It might not be strong enough to completely suppress the possibility for some isolated/scattered diurnally driven precip, but the added subsidence should make it a bit more difficult into the weekend. A weak backdoor frontal boundary try to sag closer to NE parts of the CWA Sunday, then further SW into the area early next week which should allow for slightly better POPs/coverage. 47

AVIATION

(18Z TAF Issuance) Issued at 116 PM CDT Tue May 26 2026

Generally VFR conditions expected through this evening. Scattered -SHRA are occurring near KIAH/KCXO/KUTS. This activity will continue for a couple more hours before dissipating. Short term Convection- Allowing Models in good agreement on an MCS forming in the Hill Country this afternoon and pushing eastward across SE TX during the overnight hours tonight. Have placed TEMPO groups for TSRA with strong wind gusts (30+ knots) and reduced visibilities in all the terminals for the initial push of the MCS. Generally leaned toward the earlier timed solutions given the system being progressive but timing may need to be adjusted by a couple of hours in later updates. SHRA/-TSRA will linger through mid to late morning Wednesday with MVFR ceilings especially for Houston terminals and coast. Some models are showing convective redevelopment Wednesday afternoon but this is low confidence right now. 35/MM

MARINE

Issued at 116 PM CDT Tue May 26 2026

A band of potentially strong showers and thunderstorms will be moving into the area from the west and northwest overnight. In terms of timing, current forecasts indicate the favored time period for the most significant weather in the Matagorda Bay area should be between 1-5am, Galveston Bay 3am-7am, and the Gulf waters 3am-10am. Keep in mind, these systems can, and sometimes do, run ahead of schedule and arrive earlier. Take this into consideration before beginning or continuing your transits. The primary risk from these storms will be abrupt wind shifts and gusts to 30-50kt, heavy rain, and lightning. Lingering rainfall should begin tapering off throughout the morning and afternoon on Wednesday. More typical seasonable weather is then anticipated going into the weekend with light onshore winds, low seas, and slight chances of showers and thunderstorms each day. 47

HYDROLOGY

Issued at 116 PM CDT Tue May 26 2026

Most streamflows in southeast Texas are at, above, or much above normal thanks to recent rainfall, which means any rainfall will likely become straight runoff. That being said, the current forecast (1-2 inches) does not lead us to believe there will be widespread river flooding with this next system, we will need to monitor rises on area rivers, bayous and creeks especially where the heaviest rain (3-5 inches) falls. The latest run with probabilistic QPF shows rises to action stage across most of the river basins in southeast Texas over the next 72 hours; however, a few spots along flashier tributaries show minor flooding is possible. Remember that you can monitor updated river forecasts via the NWS NWPS webpage (https://water.noaa.gov/). KLG

PRELIMINARY POINT TEMPS/POPS

College Station (CLL) 70 79 70 85 / 90 60 20 30 Houston (IAH) 73 78 72 87 / 90 90 30 60 Galveston (GLS) 77 81 77 85 / 100 80 30 50

HGX WATCHES/WARNINGS/ADVISORIES

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