textproduct: Houston/Galveston

KEY MESSAGES

- Uneventful, muggy conditions will continue through the weekend with a low chance of isolated showers and thunderstorms.

- Confidence continues to increase on wetter, more impactful weather across southeast Texas with 2 to 4 inches of rainfall more likely in the next 7 days.

- Beach conditions: localized minor coastal flooding will be possible during times of high tide mainly near Galveston Bay through the weekend. A high risk of rip currents is also expected along all Gulf- facing beaches.

DISCUSSION

Issued at 109 PM CDT Sat May 16 2026

By late tonight into Sunday, a mid to upper level longwave trough continues to deepen over the Rockies with several shortwaves ejecting east-northeast toward the central and southern Plains. This system is also bringing more Pacific moisture embedded in the west- southwest flow. At lower levels, a developing low will continue to strengthen the 850mb jet, leading to an increase in low-level Gulf moisture further inland. Therefore, with significant warm air advection and isentropic upglide, we cannot rule out isolated showers and a few lightning strikes late tonight into early Sunday morning.

A relatively dry, warm and humid day is expected on Sunday with mostly cloudy skies and highs generally in the mid 80s to low 90s. Any showers that develop should be short-lived. The main story will be heat indices reaching the upper 90s to low 100s in the afternoon. Please, be sure to practice heat safety, especially if you have outdoor plans in the afternoon and early evening.

After a week of little to no rain, the upcoming week is shaping up to be wetter with daily chances for showers and thunderstorms, especially during the peak daytime heating. Models continue to indicate PWAT values close to or at the daily max of climatology for mid to late May standards. Sufficient moisture paired with a parade of shortwaves aloft through the week will be enough to produce scattered to widespread activity. The best chances will occur late Tuesday into Thursday as a stronger shortwave and an approaching frontal boundary move close to Southeast TX. There is medium to high confidence that we will receive rain next week. However, confidence regarding total amounts, timing, and the location of the heaviest rain is still low to medium as it will depend on the actual track of these shortwaves. Based on the latest guidance an estimated rainfall total of 2 to 4 inches will be possible Monday through Friday, with the highest totals over the Brazos Valley and Piney Woods region. Localized higher amounts will be possible. WPC highlights this risk of excessive rainfall in their Day 5 outlook. Specific details like rainfall totals, coverage, timing and intensity will be monitored closely as high resolution forecast models converge on a solution.

JM

AVIATION

(00Z TAF Issuance) Issued at 605 PM CDT Sat May 16 2026

For the 17/00Z TAF update, a continuing onshore wind pattern remains underway across southeast Texas airspace. Another subsequent round of MVFR cigs is expected to begin developing by 17/02-04 and continue through 17/15Z before mixing and gradual VFR improvements return by 17/16 through the end of the main period. The next round of MVFR cigs will begin to approach KIAH once again by 18/03Z. With progressive southeasterly winds, fog development will be inhibited through the period.

Cassel

MARINE

Issued at 109 PM CDT Sat May 16 2026

Moderate onshore winds and seas up to 4ft across the nearshore waters, and 5 to 6 ft well offshore will persist through the weekend. Small craft should exercise caution this weekend as gusts up to 20+ kts can be expected. Winds and seas may reach advisory levels early next week as several disturbances move through the region. A daily risk of showers and thunderstorms is also expected through the end of the upcoming week.

Hazardous beach conditions are expected through at least early Monday. Persistent onshore winds could potentially result in localized minor coastal flooding, particularly during times of high tide. Latest model guidance continues to indicate water levels between 3.4 and 4.0 ft MLLW during high tides along the Bolivar Peninsula and Galveston Island through early Monday. Strong rip currents are also expected and have been confirmed by the Galveston Beach Patrol. A Beach Hazards Statement remains in effect through at least Monday morning.

JM

PRELIMINARY POINT TEMPS/POPS

College Station (CLL) 74 90 76 89 / 20 20 20 20 Houston (IAH) 76 89 77 88 / 20 20 10 30 Galveston (GLS) 76 85 79 86 / 10 10 10 10

HGX WATCHES/WARNINGS/ADVISORIES

TX...Beach Hazards Statement through Monday morning for TXZ436>439.

GM...Small Craft Should Exercise Caution through Sunday morning for GMZ330-335-350-355-370-375.