textproduct: Houston/Galveston

KEY MESSAGES

- The long stretch of unseasonably warm weather with temperatures 10-25 degrees above normal continues. Both afternoon highs and overnight low temperatures will be near record values.

- Daily visibility reductions due to fog and sea fog, especially across the bays and coastal areas. The main threat for fog will be during the nighttime and early morning hours, especially tonight through Friday morning.

- The Last cold front of 2025 is anticipated to move through the area on Sunday, setting us up for some colder than average conditions Monday, gradually warming back up towards average heading into New Year's Eve.

DISCUSSION

Issued at 1148 PM CST Tue Dec 23 2025

Get a couple days off for the weekend, come back and...the majority of the forecast is exactly the same. This is clearly not one of those times where "if you don't like the weather, wait five minutes and it will change". In this setup, with this ridge, at this time of year, it's gonna be more like five days. Actually, almost exactly! We are slated for a cold front to move through the area sometime on Sunday (probably late afternoon to early evening, but the precise timing is still somewhat fluid this far out).

Until then, we keep on keeping on with near-record temperatures, humid conditions, and nightly rounds of fog, impacting the coastal counties, bays, and Gulf waters at the least, but expanding to some extent inland depending on each night's specific circumstances.

How unseasonable are these conditions? Well, if the multiple tied records over the past few days aren't enough indication, we can look at how strong the ridging is, and this is where I wish I could paste in pictures to the AFD. One handy tool for this is the ensemble situational awareness tables for the NAEFS and EPS, and for upper level heights, it's just a sea of red squares saying "MAX" through Thursday evening. Things start to break down later in the week ahead of Sunday's front, but by "break down", I just mean a whole lot of 90th to 99th percentile geopotential heights. Y'all, this is a strong ridge for late December.

In some ways, that's probably a good thing because precipitable water is up above the 90th percentile with the unusually high temps and persistent onshore flow. Were we to be looking at storms, we could get some pretty high rain rates out of this environment. Even despite the ridging, I have some slight chances for some real light showers near the coast. More likely, though, we'll experience this airmass the way we have for several days now: regular threats of fog, especially at the coast.

My hope had been that by this point, the shallow waters would have warmed up enough that we'd be able to see an end to the fog threat. And while waters are warming, they are still mostly in the 63-67 degree range, near or slightly below dewpoints. And at this point, the fog may be persistent enough even into the day, that we're losing precious opportunity given the low solar angle to meaningfully put an end to the fog threat. So, while warmer waters and a veering of winds to more south/southwesterly by Friday night that we may disrupt sea fog formation somewhat, we can't really confidently say the overnight/morning fog potential will be definitively gone until drier air surges in after Sunday's front.

Speaking of after Sunday's front, we finally get some real change! First, we'll see some of our first real chances at some rain in a while, primarily at the coast. Because the upper levels are so warm, we'll still struggle to get convection going in spite of the rich boundary layer air, so don't get too excited. But we should manage at least some scattered showers off the frontal surface aloft Sunday evening.

More impressive than the rain chances will be the temperature change. From highs in the upper 70s and lower 80s on Sunday (assuming the front arrives too late to chop down afternoon temps), Monday's highs dive into the 50s for the vast majority of the area. Some folks way up in our northern fringes may struggle to even exceed 50 degrees. Monday night/Tuesday morning lows look to see a light freeze return to at least the northernmost portions of the area, with widespread lows in the 30s and even down around 40 degrees to the Gulf beaches.

This all sounds impressive, and in a way it is...but also...these temperatures I'm describing are only 5-10 degrees below average. So, despite the big drop in temps, and the arrival of some winter chill, we don't look to get unseasonably cold after this front. Also, and stop me if you've heard this before already this season, but the dip to the cold side of average doesn't look to stay in place for too long, either. As we head to the end of 2025, we should see things gradually begin to make their way back upwards, and we look to end the year on a downright seasonable note.

AVIATION

(12Z TAF Issuance) Issued at 541 AM CST Wed Dec 24 2025

A mix of LIFR to IFR conditions currently over Southeast TX due to low cloud decks and areas of patchy to dense fog. Conditions are expected to gradually improve after 14-15Z as fog burns off and cigs gradually rise. Conditions may be slow to recover at GLS and LBX due to the influence of sea fog continuing over the bays and nearshore waters. Clouds could scatter out for several locations in the afternoon to early evening hours. However, cloud decks will return and lower once again tonight into Wed morning. Patchy to dense fog will also reduce vis again for several locations, in particular for sites south of IAH. SE-SSE winds will be 5-10 KTS today and relax back down to 5 KTS or less tonight.

Cotto

MARINE

Issued at 1148 PM CST Tue Dec 23 2025

Fog, dense in spots, continues to overspread the bays and nearshore Gulf waters this evening. Foggy conditions will carry into Wednesday morning. We should see some improvement mid-day into the afternoon, particularly over the bays. On the Gulf, fog may not entirely dissipate, but there should be a brief reprieve from dense fog. Sea fog will likely return nightly through at least Friday with some patches possible through the early weekend.

Beyond the fog, light onshore winds and low seas prevail through Saturday. A cold front will move through the area on Sunday. Small craft advisories may be needed Sunday night into Monday as strong northeast winds develop behind the front. There is some potential that even gale conditions could be seen on portions of the coastal Gulf waters - something to monitor in the forecast as we head into the weekend.

CLIMATE

Issued at 1148 PM CST Tue Dec 23 2025

The record high of 81 degrees was tied for the City of Houston earlier today. With temperatures not likely to change significantly until Sunday's front, records may potentially be tied or broken through the end of the week. At the very least, we will be much closer to those records than we will be to seasonal averages.

As a quick summary, record highs at the two Houston climate sites (IAH, Hobby) range from 81-84 over the next five days, while record high min temps range from 68 to 75 degrees. College Stations records range from 81 to 86 for highs and 65 to 73 for high mins. Galveston's record highs range from 78 to 80 for max temps, and 67 to 71 degrees for record high min temps.

Luchs/Fowler

PRELIMINARY POINT TEMPS/POPS

College Station (CLL) 81 63 82 63 / 0 0 0 0 Houston (IAH) 80 64 80 65 / 10 0 0 0 Galveston (GLS) 74 64 75 64 / 10 10 10 10

HGX WATCHES/WARNINGS/ADVISORIES

TX...Dense Fog Advisory until 10 AM CST this morning for TXZ178-179- 199-200-213-214-226-227-235>238-300-313-335>338-436>439.

GM...Dense Fog Advisory until noon CST today for GMZ330-335-350-355.