textproduct: Houston/Galveston

KEY MESSAGES

- Gusty winds and much colder temperatures are surging into the area in the wake of a strong cold front. Expect temperatures to drop in the vicinity of 30 degrees from Sunday afternoon's highs to Monday afternoon. A light freeze can be expected for at least a portion of the area Monday and Tuesday nights.

- A Wind Advisory has been issued where there is a high chance (at least 75 percent) of sustained winds around 25 mph, and gusts up to 45 mph. Outside of the advisory area, the potential for winds is only modestly lower - with sustained winds of 15-20 mph likely and occasional gusts reaching to 35 mph. - Marine areas will also be quite windy, with a Gale Warning for all coastal waters until mid-day Monday, and persisting on coastal Gulf waters until evening. Strong winds, hazardous seas, and low bay water levels will make marine travel treacherous.

DISCUSSION

Issued at 1217 AM CST Mon Dec 29 2025

I would not blame you, Dear Reader, if you were getting sick of my nightly discussions talking about this big, strong cold front that was going to be coming through while we sweated through an unseasonably hot stretch with multiple heat records. (You *are* reading every single one of my discussions, right? Right!) But finally, at long last, that front is here and making its way through the Loop as I type. We've already seen winds swing around to northerly and spike into the 20-25 mph range with gusts above 30 mph. We can expect these winds to spread their way coastward over the next couple of hours, and over the coastal waters through the night and into Monday.

To go with the winds, we have a bevy of wind-related advisories and warnings to go with them! A Gale Warning is about to kick in on all coastal waters as we shall see winds rise to those conditions shortly after the front passes, complete with hazardous seas. You can read more about that in the marine section below. On land, we have a wind advisory covering the large majority of our area - the coast, as well as the western portion of our area from the western edge of the Houston metro out to where we hand things over to our neighboring offices (spoiler alert: our responsibility ends, but the wind advisories don't).

Why not all of the area? Well...with binary yes/no things like a wind advisory, we have to draw the line somewhere, and for this in particular it is sustained winds (or frequent gusts) of 25 mph. In the advisory area, these winds are quite likely - NBM probabilities for a 25 mph sustained wind are 70 percent or higher. Outside of the area, with the exception of the waters of Lake Livingston, that probability drops to functionally nil, except for inland Harris County, which gets up to the 10-15 percent range. Possible, but not likely. But...that doesn't mean it won't be windy in these places! It just means that we're very confident that winds look to be just a little bit below the threshold. So, while we expect winds to get up to around 25 mph with gusts to 45 mph in the advisory area, outside that expectation really only slips to around 15 mph with occasional gusts to around 35 mph! Still breezy for sure...and if we find the winds outperforming all model expectations, a short-fuse advisory could be needed.

Those strong winds will be bringing in much chillier temperatures, as well. I've been mentioning for a bit now that Sunday afternoon to Monday afternoon temperature differences could be in the 30 degree ballpark, and that's still the expectation tonight. This will bring us from record heat to something that is colder than average for late December, but not unreasonably so. But the arrival of "somewhat typical winter" will be a big shift from "second? third? fourth? I've lost count summer".

The return of wintry temperatures does also bring up the discussion of freeze potential. Tonight will not really have that potential. We're just starting the cold advection machine, and only the far north around Houston and Madison counties are really expected to fall into the middle 30s at most. It's just the start, though. I still don't expect us to rise much above those morning lows on Monday, only reaching into the upper 40s to around 50 degrees area-wide, setting us up for more chill Monday night into Tuesday morning. At this point, I have lows in the 30s all the way to the beaches (congrats, Galveston, you may stay just above 40) and a light freeze north of the metro. Going back to the NBM distribution, we're looking at something up around 90 percent for sub-32 lows in Crockett and 60 percent in Livingston, but already down to the 20-25 percent range for places like College Station, Huntsville, and Conroe. If that feels a little low for College Station and Huntsville, you're probably right. a similar HREF probability is actually more like 50 percent for freezing temps, but Conroe is still around 20 percent. So, a good reminder that model probabilities are not true probabilities, but the same general pattern is holding across systems!

Now, when it comes to the coldest night, I'm still eyeing Tuesday night into Wednesday morning. Tuesday should be a little warmer than Monday thanks to more sun, and drier air heating more efficiently, but we're still close to the winter solstice, so it's not going to be *that* much warmer, still in the 50s area-wide. And what the clear sky and high pressure can't quite do for daytime heating, it will more than make up for it with radiational cooling at night. Our day shift started to get even bolder with lows Tuesday night, and I am completely inclined to follow them, with low temps right down to 32 as far south as Angleton! Coastal areas should stay chilly but above freezing, as well as the bulk of the Houston metro. But, for areas outside of there, and even on those northern and western fringes of the metro, a light freeze appears likely.

If you guessed that means I'm going back the NBM probabilities, you'd be right! From the Piney Woods down to the Southeast through Lake Livingston and parts of Liberty County, the sub- freezing lows probability is functionally 100 percent. It's gonna happen. Those probabilities are so high, we're going to want to slide that down to the potential for lows below 25 and hard freeze criteria...and thankfully those numbers are lower, largely less than 25 percent. Still, isolated spots (mostly in Houston County, but also Polk, San Jacinto, and Liberty) do see a hard freeze probability in excess of 30 percent, so it's not impossible.

Elsewhere in the area, we thankfully don't have to worry about hard freeze potential, but a light freeze is very much on the table. Places where freezing temps are more likely than not? Think Caldwell, College Station, Huntsville, Conroe, Spring, Katy, Brenham, places right up to the northern and western fringes of the Houston metro and north of I-10. South of I-10, we're not much behind - so places like Wharton, Bay City, and Angleton, it may be more of a coin flip per the NBM. I do actually have a little more confidence, which is why our official forecast low takes freezing temps into this area southwest of the Houston metro. Places where the chances are low - 20 percent or less, will be the urban core of Houston, as well as the immediate coastal areas, where things should be quite chilly, but also unlikely to reach freezing.

From Wednesday onward, there still seems to be a general consensus for fair weather and a warming trend. I largely follow the NBM as it seems to grasp the trend pretty well, bringing us back to afternoon temps in the 70s for most all of us by Thursday. One thing that does stand out to me is the potential passage of a weak, Pacific "cold" front Friday night. Yeah, complete with the scare quotes around "cold". I'm actually making the fingers. With little to no meaningfully colder air behind the front to knock temps down at all, but with plenty of sun on the backside of the front, these fronts are actually followed by a warmer day following their passage - sometimes much warmer! If this were late spring, I'd be musing about the potential for record highs. While the deterministic NBM makes things a bit cooler on Saturday, I instead opted to go with the median of the NBM distribution. You wouldn't think that would be much of a change, but this shows much better a scenario where we actually get warmer after the front goes through!

AVIATION

(12Z TAF Issuance) Issued at 420 AM CST Mon Dec 29 2025

After several days with reduced ceilings and visibilites, we can finally say the magic words thanks to a cold front that pushed through last night/early this morning: VFR conditions will prevail throughout the entire TAF period. Radar reflectivity reveals some lingering light rain showers that will prevail over the next few hours. However, with much drier air moving in, rainfall reaching the surface will become increasingly unlikely (drizzle or virga most likely outcome). Moderate to strong northerly winds will prevail throughout the afternoon with sustained winds in the 15-25 kt range with gusts up to 25-35 kt. Winds gradually subside into the evening and overnight hours, but will remain elevated closer to the coast.

Batiste

MARINE

Issued at 1217 AM CST Mon Dec 29 2025

The last gasps of patchy dense fog is occurring at the coast, but will be scoured out in the next few hours by a strong cold front. The front is carrying scattered showers along with it, and there may be a small chance of a stray lightning strike as well as the front pushes across the waters overnight.

Very strong north winds, hazardous seas, and low water levels are expected in the front's wake. Currents may become strong near the interface of the rivers and the bays during times of low water, which may particularly be an issue on Galveston Bay. Winds and seas slowly improve late Monday into Tuesday, though low water will likely persist through at least Tuesday's low tide cycle and potentially deeper into the week.

FIRE WEATHER

Issued at 1217 AM CST Mon Dec 29 2025

A strong cold front is sweeping across Southeast Texas this evening, carrying a thin line of scattered showers along with it. Behind the front, strong and gusty northerly winds are developing in the front's wake. Wind gusts in above 25 mph are virtually certain across the area, and sustained winds above 25 mph are more likely than not in open areas near and west of the Brazos River. In these open western areas and near the Gulf coast, occasional gusts as high as 40 to 45 mph may be seen. Along with the gusty winds, we'll also see much colder and drier conditions behind the front. Indeed, as those strong winds are gradually declining through the afternoon, we'll see an overlap with afternoon RH values dropping to the 15 to 25 percent range.

Monday could be a day with consideration for a red flag warning, but the weather conditions should be mitigated by fuels that are near or above normal moisture, per Texas A&M Forest Service data. Still, with strong winds and low RH, it would be best to postpone plans involving fire as much as possible. This is particularly true in locations dominated by grasses, as these fine fuels will respond very quickly to the dropping humidity.

PRELIMINARY POINT TEMPS/POPS

College Station (CLL) 49 35 55 32 / 0 0 0 0 Houston (IAH) 53 37 54 34 / 0 0 0 0 Galveston (GLS) 52 43 51 43 / 10 0 0 0

HGX WATCHES/WARNINGS/ADVISORIES

TX...Wind Advisory until 6 PM CST this evening for TXZ176-195>198- 210>212-214-226-227-235>238-313-335>338-436>439.

GM...Gale Warning until noon CST today for GMZ330-335.

Small Craft Advisory from noon today to noon CST Tuesday for GMZ330-335.

Low Water Advisory until 6 PM CST Tuesday for GMZ335.

Gale Warning until 6 PM CST this evening for GMZ350-355-370-375.

Small Craft Advisory from 6 PM this evening to noon CST Tuesday for GMZ350-355-370-375.