FXUS64 KHGX 280637 AFDHGX Area Forecast Discussion National Weather Service Houston/Galveston TX 1237 AM CST Sun Dec 28 2025 ...New DISCUSSION, MARINE... .KEY MESSAGES... - Very warm and muggy weather is in place for one more day. Expect patchy fog, particularly near the coast, in the morning and potentially again for a brief portion of Sunday evening. - A strong cold front late Sunday night into Monday morning will bring much colder conditions early next week, followed by a slow warmup deeper into the week. A light freeze is very likely north of the Houston metro, with lower chances in the northern suburbs and rural areas west of the metro. - The gale watch on coastal waters from Sunday through Monday has been upgraded to a gale warning. On land, a wind advisory is in place for late Sunday night and Monday to match. In addition to the strong winds and rough waters, mariners will need to prepare for low bay water levels and strong currents where area rivers and bayous enter the bays Monday and Tuesday. && .DISCUSSION... Issued at 1237 AM CST Sun Dec 28 2025 Another handful of records fell today from our long, holiday hot stretch, and we will have one more day of this to go. However, the much-anticipated cold front is on its way, and set to move through the area Sunday night into early Monday morning, bringing a much different set of conditions for early next week. Starting with where we're at now, it is still very unseasonably warm, and the warm, muggy conditions are fueling some fog across the area, but mostly very near the coast. Like the last couple of nights, we are seeing less intense fog than earlier last week - however, some patches of more dense fog are still cropping up, as a few obs of 1/4 to 3/4 miles are still be reported at times. While this isn't widespread enough to require any sort of advisories at this time, travelers on land and sea should be prepared for abrupt, sometimes dramatic changes in visibility due to the fog tonight through the morning. At the coast, there will be one last window for fog Sunday evening before the front arrives. Between the two fog windows, we'll also get one last shot at some daily records, at least for afternoon record highs. The morning low temps may manage to be eclipsed at midnight as the first bits of cold air come in behind the front. It could go either way, we'll probably be watching things right up to midnight. Going back to the afternoon highs, the deterministic NBM went a bit cooler than today for highs. This is not unreasonable, given we may have enough cloud cover to hold things in check. But with the front trending a little bit faster, we may find ourselves in a spot with it close enough to boost temps slightly through compressional heating. I'm buying into this, so I swapped the NBM for the median of the NBM distribution. It's a subtle change, but is roughly persistence or slightly warmer instead of slightly cooler. We will find out if I'm right on this shortly! This front will be accompanied be showers and perhaps a thunderstorm or two on Sunday night. Confidence in scattered to numerous showers really is quite high, and the only thing keeping PoPs from being extremely high is that more scattered character rather than a widespread rain shield. It turns out that for all the hyping up of this front we're doing, the upper support is not nearly as supportive of convection as one might expect - a consequence of the upper trough only being able to dig into the Central Plains against this strong ridge. This will also disrupt the efficiency of any rains, keeping QPF pretty low. This is a situation where confidence is very high in both that there will be rain, and also that any rain there is will be light. Once the front moves through - entering the area a little after sunset (roughly 7 pm) and pushing off the coast around midnight - the first thing we're going to see is for strong north winds to crank up for the late night hours through Monday. A wind advisory is slated to take effect from north to south shortly after the frontal passage, eventually covering most of our area for Monday. In the advisory area, chances are high (70-100 percent) that sustained winds will reach to around/above 25 mph, with similar confidence in wind gusts around and above 35 mph. If you've got some light and/or unsecured Christmas decorations still up, Sunday is going to be a very, very good day to bring them down, even if it is hot out there. There is a portion of the area, from inland Harris County and Liberty County northward to the Piney Woods, where we don't currently have a wind advisory issued. This is not because it won't be windy there - indeed, winds will likely be near the advisory threshold. However, the confidence that we'll actually manage to see sustained winds or frequent gusts above 25 mph is noticeably lower. Except on the waters of Lake Livingston, NBM probabilities of sustained winds over 25 mph outside of the advisory area are functionally nil. We are likely to see higher gusts and even a medium chance (40-70 percent) of getting a gust to 35 mph, but the signal for consistent advisory-level winds just isn't there like it is elsewhere in the area. That said, if the winds end up overperforming and we begin to see persistent high gusts, that could require a quick addition of this last chunk to the advisory area. The next impact after the winds will be a surge of much colder, drier air into Southeast Texas. High temperatures across the area for Monday will almost certainly be "whatever the temperature is at midnight". In the afternoon, while we should get a bit of warming from the morning lows thanks to a bit of sun breaking through the clouds, but cold advection will work hard to keep that rise in temps as close to zero as possible. So yes, Monday afternoon looks to be mired around 50 degrees, give or take a few, and a solid thirty degrees lower than is being forecast for Sunday afternoon! That cold advection won't have had enough time to do its work right after the front, so morning lows Monday morning won't be terribly low, mainly in the 40s. It's more Monday and Tuesday night that we'll be looking for the coldest nights. Monday night should get the full benefit of 24 hours of cold advection, and chances of a light freeze around the Piney Woods and Lake Livingston are high - above 50 percent. Elsewhere...not so much, but are still 15-25 percent west of the metro from B/CS down to I-10. Not a strong chance, but it exists for sure. Tuesday night looks like the chilliest night of this stretch. By then, high pressure should be settling in, giving us a clearer nighttime sky, light winds, and short of a fresh snowpack, about as ideal of a radiational cooling setup as we could ask for. Like past nights, I keep freezing temps mostly hemmed up north of the Houston metro, beginning to edge into the northern suburbs. West of the metro, and even in the rural areas southwest of the metro and southward as far as inland Matagorda and Brazoria counties, I bring temps very close to freezing, but not explicitly below them. But while that implies my lean to not getting freezing temps that far south, it's very close for a reason, and it would not be a big surprise to get a freeze, especially in localized cold spots. If you are in a river valley, particularly the Brazos, a brief dip to freezing may be more likely than not, as NBM probabilities there get as high as 75 percent. In general, this area west of the metro and north of I-10 have medium chances of hitting the freezing mark, 40-60 percent. South of I-10, it's not quite as high, but it still wouldn't be a huge surprise. In Jackson, Wharton, inland Matagorda, and the rural western parts of Fort Bend and inland Brazoria counties, those NBM freezing probs are in the 25-45 percent range - nearly a coin flip! Some spots close to the coast do get as high as 60-65 percent, but I think this is somewhat spurious, as you can see a weird, high bullseye there on Monday night, when chances are even lower. Potentially a bias correction artifact. I'd be much more inclined to sticking with that 25-45 percent range across this area. For Wednesday and beyond, the story remains very close to the same. With zonal flow or even some weak ridging aloft setting up, we should mostly be looking for fair weather and a slow, gradual warmup for the second half of the week. While models are still pretty unanimous on a shortwave trough making its way through the upper pattern in this latter part of the week, they have unhappily gotten less in agreement on the timing. Not a surprise given the relative subtlety of these features, but still a bummer for the forecast. As a result, the rain chances I had at the very end of the forecast period have largely disappeared. Should we get the shortwave rolling through more in the mid-week when we're still dry, rain chances will be slim to none. If it's later in the week and especially if it matches up with a weak Pacific front, we'd have a better potential for rain...but without the confidence of it happening that late, I can't really justify having mentionable PoPs anymore. Once things start to firm up on how this plays out, we'll be able to speak with more confidence on it. && .AVIATION... (00Z TAF Issuance) Issued at 540 PM CST Sat Dec 27 2025 VFR conditions are expected through around 06Z Sunday. Low clouds will form starting 06-09Z for Houston area terminals northward with low MVFR/IFR conditions expected. Surface winds are expected to be stronger tonight which should result in less fog development for the inland terminals than what was seen last night. Still expect periods of visibilities of 3-6SM mainly 10-15Z Sunday. Patchy sea fog will develop over Galveston Bay and will impact KGLS terminal. Ceilings will improve for inland terminals between 15-20Z Sunday. Expect southerly wind gusts of 15-20 knots in the afternoon. Strong cold front will cross the terminals Sunday night with timing 01-03Z KCLL, 03-06Z Houston terminals, and 06-08Z KGLS. Scattered -SHRA will form along/behind front with brief period of reduced visibilities in rain possible right at FROPA. && .MARINE... Issued at 1237 AM CST Sun Dec 28 2025 Patchy dense fog is possible tonight into Sunday morning embedded within broader areas of less dense fog. This will be possible again Sunday evening ahead of an approaching cold front. The front will bring a chance of showers and isolated thunderstorms as it pushes offshore Sunday night into Monday morning. Very strong north winds, hazardous seas, and low water levels are expected in the front's wake. Gale conditions are likely, and a gale warning has been issued. Currents may become strong near the interface of the rivers and the bays during times of low water. Winds and seas slowly improve late Monday into Tuesday, though low water will likely persist through at least Tuesday's low tide cycle. Indeed, negative tides may be more apparent for Tuesday's low tide than for Monday's. && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 67 83 41 50 / 0 0 20 10 Houston (IAH) 66 83 46 52 / 0 0 30 10 Galveston (GLS) 66 74 49 52 / 0 0 60 20 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...Wind Advisory from 9 PM Sunday to 6 PM CST Monday for TXZ176- 195>198-210>212. Wind Advisory from midnight Sunday night to 6 PM CST Monday for TXZ214-226-227-235>238-313-335>338-436>439. GM...Gale Warning from midnight Sunday night to noon CST Monday for GMZ330-335. Gale Warning from midnight Sunday night to 6 PM CST Monday for GMZ350-355-370-375. && $$ DISCUSSION...Luchs AVIATION...35 MARINE...Luchs