textproduct: Houston/Galveston

KEY MESSAGES

- Rain and thunderstorms likely on Sunday.

- Strong to severe thunderstorms, locally heavy rain, and gusty coastal winds will be the primary concerns on Sunday. Hazardous marine conditions are expected.

- Colder air and strong marine winds expected Sunday night into Monday. Gale Watch in the bays and Gulf during this time frame.

UPDATE

Issued at 535 AM CST Sat Nov 14 2026

Sent out a quick update to begin the start time of the Small Craft Advisory to begin now. Also issued a Beach Hazard Statement to incorporate the high risk of rip currents along area beaches through the weekend and the risk of some minor coastal flooding late Sunday into Monday. 47

DISCUSSION

Issued at 1046 PM CST Fri Nov 13 2026

An active weather pattern is on our doorstep as we step into the weekend. A deep, W CONUS trough with a negatively tilted axis extends from the PAC NW into the Four Corners Region. Ahead of the trough axis is an elongated shortwave that will push through Texas on Saturday, bringing increased cloud cover and isolated to scattered showers (especially in our western zones). Meanwhile, easterly sfc flow is tapping into colder air over SE CONUS, resulting in a weak CAA regime. This regime, coupled with increased cloud cover, will likely keep temperatures cooler on Saturday than previous days. Afternoon temperatures are expected to average in the 60s, though our southwesternmost zones may still find themselves reaching the low 70s. Then on Sunday, things become more interesting.

A strong mid/upper low is expected to cut off from the parent W CONUS trough. The low should track through the TX Panhandle and Oklahoma on Sunday. The mid/upper levels will feature a strong, diffluent jet, creating an increasingly sheared and synoptically lifted atmosphere. The atmosphere is expected to be prime for LL cyclogenesis, which is supported by the strong model guidance consensus depicting a LL low pressure system that tracks southeast across the Lone Star State on Sunday. The ML/UL forecast appears relatively straight forward. But things get tricky when looking at the lower levels.

Let's start with the aspects of Sunday's forecast for which we have relatively high confidence.

1) There is a high chance of widespread shower and thunderstorm activity on Sunday. 2)There will likely be locally heavy rainfall capable of localized flooding (especially near the coast). 3) Strong, gusty winds are expected in our coastal and marine zones through the weekend and into Monday (likely through at least Tuesday in the Gulf). 4) The vertical wind profile will be favorable for strong to severe thunderstorms on Sunday. 5) Instability parameters on Sunday will favor strong to severe thunderstorms within the system's warm sector, ahead of the low's associated cold front and south of its warm front.

The uncertainty grows once we start looking at the details of point #5. There is strong model guidance support that at least parts of our CWA will find themselves in the warm sector of this system. But how much of the CWA will be in the warm sector? Will CAA from the east be enough to suppress the warm front southward, limiting the favorable severe weather set up to our southwestern counties, coastal areas, and offshore Gulf zones? Or could WAA ahead of the strengthening low amplify the warm front northward? That second scenario would place more of our region within the warm unstable sector of the system. This is where the forecast becomes much more uncertain. It's worth mentioning that this uncertainty also has huge implications on Sunday's high temperatures (steep temperature gradient over short distances).

For now, rain and thunderstorms appear to be a safe bet across the CWA on Sunday. Our northern Piney Woods zones are most likely to remain in the chilly airmass, with temperatures holding into the 50s (and possibly falling into the 40s late in the day). MU CAPEs coupled with the sheared environment suggest elevated deep convection north of the warm front is possible. But areas within the warm sector have the best chance of thunderstorms capable of large hail, damaging winds, and even tornadoes. Fcst hodographs suggests discrete convective modes are on the table, which raises the large hail and tornado concern. So hopefully the set up can manage to suppress the warm front farther south, limiting the SE Texas surface area within the warm sector.

The low pulls eastward late Sunday and into Monday. But the signals in the guidance do not point to a total clearing out on Monday due to modest isentropic lift over the LL CAA regime in the low's wake. Our current forecast shows plenty of clouds, temperatures in the 50s, and perhaps some lingering showers. Morning lows Monday and Tuesday are expected to be in the 40s for most areas north of I-10. Bush and Hobby airports are nearing their latest first sub 50 degree low of the season. So if they don't fall below 50 degrees in this event, then the record will likely be broken.

Long range guidance points towards a warming trend, with highs in the 70s by Wednesday and Thursday. Increased moisture from onshore flow could introduce a low chance of showers by mid/late week. But for now, the best chance of mid/late week rain appears to be west of our region. But time will tell.

Self

AVIATION

(12Z TAF Issuance) Issued at 535 AM CST Sat Nov 14 2026

VFR conditions, but increasing easterly winds today. Tonight, we'll see a weak upper level disturbance pass through. Some scattered showers are anticipated though tough to pinpoint specific times, etc so just added some PROB30's and VCSH's. Ceilings will trend downward as we head into the late night and morning hours Sunday...possibly into the 1500-2500ft range. Shower and thunderstorm chances increase around the CLL area around or shortly after sunrise Sunday...and the metro and coastal areas as the day progresses. 47

MARINE

Issued at 1046 PM CST Fri Nov 13 2026

Easterly winds and Gulf seas will increase on Saturday as the gradient tightens between high pressure over E CONUS and an approaching system from the west. Small Craft Advisory level conditions are likely across all of our waters by Saturday evening. Rain and thunderstorm chances increase on Sunday. Ambient winds are expected to generally be Small Craft Advisory level. However, gales are likely within stronger thunderstorms. In addition, we cannot rule out hail and waterspouts on Sunday as well. Winds will increase from the northeast as the system pulls eastward Sunday night into Monday. A Gale Watch is in effect during this time frame for the Gulf and bays due to the prospect of frequent gusts to gale force (especially over the Gulf). In addition, bay waters will become rough while offshore Gulf seas likely top 10 feet. The gradient eases on Tuesday, but Small Craft Advisory level conditions will likely extend into Tuesday and possibly Wednesday for the offshore Gulf.

PRELIMINARY POINT TEMPS/POPS

College Station (CLL) 70 51 61 46 / 10 60 90 50 Houston (IAH) 68 54 65 48 / 0 30 90 70 Galveston (GLS) 70 64 73 55 / 0 30 90 90

HGX WATCHES/WARNINGS/ADVISORIES

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

GM...Small Craft Advisory from 9 AM this morning to 6 PM CST Sunday for GMZ330-350-370.

Gale Watch from Sunday evening through Monday afternoon for GMZ330-335-350-355-370-375.

Small Craft Advisory until 6 PM CST Sunday for GMZ335-355-375.