textproduct: Houston/Galveston

KEY MESSAGES

- Isolated to scattered showers/thunderstorms possible Wednesday. Isolated severe storm cannot be ruled out.

- Higher chance of showers/thunderstorms Thursday and Friday as the next storm system approaches the area. Locally heavy rainfall possible.

- Some uncertainty regarding whether Saturday's weather. It is possible that the showers and storms could linger into the weekend.

DISCUSSION

Issued at 119 PM CDT Tue May 5 2026

Mid/upper level water vapor imagery shows a large mid/upper low roughly centered over Southern California. Ahead of the low is an enhanced and increasingly amplified mid/upper jet over NW Mexico and SW CONUS. Moisture from the Tropical Pacific is being advected along the jet into SW and central CONUS, helping to bring some of the higher level cloud cover you see in the skies above you today. In the lower levels, deep southerly flow is pushing high dew points and enhanced PWATs into east Texas from the Gulf, thanks to an enhanced LL gradient brought to you by a low pressure system over Oklahoma. The low's associated cold front, currently situated over the TX Panhandle, is surging southward and will eventually add sfc convergence and lift to the southeast Texas atmosphere later this week. For us today, expect mostly warm and humid conditions with perhaps a passing shower. Highs are expected to warm well into the 80s across portions of the CWA today.

The atmosphere becomes increasingly sheared on Wednesday as the aforementioned mid/upper low approaches from the west. Sfc-6KM Bulk Shear is expected to exceed 50 knots by the afternoon hours. With plentiful LL instability and the presence of a weak sfc boundary drifting southward (possibly outflow from earlier tstorms farther north), one might think that severe thunderstorms would be a problem for the region by Wednesday afternoon. Given the aforementioned parameters, we will need to watch the radar carefully Wednesday afternoon in case a few strong to severe thunderstorms decide to develop. However, there may be too much dry air aloft to allow for deep convection Wednesday afternoon. Forecast soundings suggest the air will be quite dry around 700 MB. Therefore, it is no surprise that the CAMs remain unimpressive regarding deep convective development. That being said, SPC continues to hold on to a Level 2 of 5 severe weather risk for our northern counties, while most elsewhere in in a Level 1 of 5. If the atmosphere can overcome the ML dry, then a few thunderstorms capable of hail and damaging winds will be possible.

As we head into Thursday and Friday, large scale lift increases as strong PVA is introduced by the approaching mid/upper low. In addition, a strong cold front is expected to surge southward, bringing enhance sfc convergence and added lift. PWATs will be quite high on Thursday into Friday, especially near the coast. This should prime the atmosphere for shower and thunderstorm activity. Given the high PWATs, there is a risk of locally heavy rainfall and localized flooding on both Thursday and Friday. We'll also need to monitor trends for a possible strong to severe thunderstorm or two. Temperatures should be cooler on Thursday/Friday, thanks to modest CAA in the front's wake coupled with increased cloud cover.

The system departs the region by the weekend, though the exact timing is somewhat uncertain. If the system moves slow enough, then showers and storms may linger into Saturday. The return of onshore flow will bring higher dew points from the Gulf, raising humidity levels through the weekend. By Sunday, many locations could be pushing 90 degrees with dew points approaching 70. Another cold front may arrive by Sunday into Monday, bringing another chance of showers and thunderstorms.

Self

AVIATION

(00Z TAF Issuance) Issued at 642 PM CDT Tue May 5 2026

MVFR ceilings will begin to gradually filter in over the evening hours and eventually becoming widespread by 06Z/Wednesday. There is potential for IFR ceilings early Wednesday morning, especially for terminals north of I-10. Cannot entirely rule out some patchy fog for CXO and terminals northward between 11Z-15Z. MVFR ceilings are expected to stick around through the entire day. Going into Wednesday morning, scattered showers will begin developing along the coast as early as 12Z and expanding over inland areas around 18Z. There is potential for isolated thunderstorms mainly after 21Z for terminals north of and including CXO, but the potential is too low to include in any of those TAFs at this time. Winds will be southerly and generally less than 10 kt. The exception to this is CLL and UTS where a frontal boundary will begin pushing into the area in the afternoon leading to a northerly wind shift. Winds will remain on the light side behind the front. Ceilings will gradually decrease again going into Wednesday evening.

Batiste

MARINE

Issued at 1123 AM CDT Tue May 5 2026

Light to moderate onshore flow and occasionally enhanced swell will continue through Wednesday night or early Thursday. A frontal boundary will push offshore Thursday, enhancing shower and thunderstorm chances on both Thursday and Friday. In addition, winds will increase from the north to northeast behind the front. For now, we are thinking winds will remain below Small Craft Advisory thresholds. However, we cannot rule out sustained winds reaching above 20 knots Thursday evening / night, especially over the Gulf. A few thunderstorms on Thursday and Friday could be heavy.

Light to moderate onshore flow returns over the weekend. The next frontal boundary may bring another chance of showers and thunderstorms by late Sunday or Monday.

PRELIMINARY POINT TEMPS/POPS

College Station (CLL) 73 82 63 72 / 0 50 30 40 Houston (IAH) 75 86 69 77 / 0 50 30 60 Galveston (GLS) 76 83 73 79 / 0 10 10 50

HGX WATCHES/WARNINGS/ADVISORIES

TX...None. GM...Small Craft Should Exercise Caution until 7 PM CDT this evening for GMZ330-335-350-355-370-375.