FXUS64 KHGX 271116 AFDHGX Area Forecast Discussion National Weather Service Houston/Galveston TX 516 AM CST Sat Dec 27 2025 ...New AVIATION... .KEY MESSAGES... - Very warm and humid conditions will continue into the weekend Overnight/morning fog remains possible across the area, but is most likely at the coast. - 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. - Gale conditions look increasingly likely after the front late Sunday night through Monday, particularly over the Gulf waters. A Gale Watch has been issued for this time. && .DISCUSSION... Issued at 1158 PM CST Fri Dec 26 2025 Well, after what seemed like endless days of heat, humidity, and fog (it wasn't really, it just felt like it after a while), we are not only able to see a change to the weather, but we're also only about 48 hours away from it! Until then, of course, we remain stuck with especially the heat and humidity. Fog seems to have loosened its grip on the region tonight thanks to winds turning more south to southwesterly, but we likely won't be rid of the fog threat completely until a cold front arrives to scour out this moisture. And on Sunday night, a cold front we shall have! It looks to move into the northernmost reaches of our forecast area late Sunday evening - somewhere in the 9pm to midnight range - and make its way towards the coast, reaching the Gulf after midnight. Strong north winds should pick up in its wake, especially in lower friction locations near the coast, and the more open area well west of the Houston metro. It's too early to get into parsing out things for something like a wind advisory, but with the probability of getting a sustained wind of 25 mph at some point on Monday being nearly 100 percent on Gulf beaches and just north of Matagorda Bay (roughly Jackson, Wharton, and Matagorda counties), and 50 percent or greater probabilities reaching all the way up the western third of the area to College Station and Caldwell, I suspect we'll need an advisory for at least a portion of the area on Monday. If you have Christmas decorations that can be easily blown away, well...Sunday is probably a really good time to take them down, even if it is hot. Of course, with a cold front and strong north winds, we're bound to see colder, drier air surging in. After a stretch of near record heat, Sunday's temps look to have in the ballpark of 30 degrees shaved off them. This is a mighty big change, but also...worth noting that a lot of that is really chopping off a lot of unseasonable heat. After that huge swing, we'll wind up roughly 5-10 degrees below average on Monday and Tuesday. A nice chill, a bit nippier than typical, but nothing unreasonably cold. I will put the same note of caution on this as I did yesterday, however. Global models, not always the best at handling the shallowest portions of post-frontal cold pools, and if there is a direction in which the forecast may trend, I would guess that it is down. As a result, we continue to hammer things out with our neighboring offices to hedge lower than the NBM deterministic for early week temperatures, and may need to adjust further. Looking at things a little more probabilistically, confidence is pretty high for freezing temps north of the Houston metro - above 60 percent, and way up north in Houston County, up around 90 percent for Monday and Tuesday night. On Monday night, things do look to stay pretty hemmed in up there, though a low chance (20 percent or less) does creep down from College Station towards I-10 west of the metro. On Tuesday night, which has a chance to see more ideal radiational cooling should the sky clear and winds die down, the odds in this area creep up. The rural west north of I-10 has something more akin to 45-65 percent chances of freezing temps, and 40 percent chances even creep into rural areas south of I-10! So, to sum up - north of the Houston metro, very likely to see a light freeze Monday and Tuesday night. West of the metro, plus some of the northern suburbs of Houston, a medium to high chance, particularly on Tuesday night. A low to medium chance even exists in the rural coastal area southwest of the metro on Tuesday night! Down here, while a low below 32 may not be the most likely outcome, it wouldn't be the biggest surprise in the world, either. A bit of a blessing here is that all of this is happening without a real strong upper trough blasting this arctic air down into Texas. In fact, the ridge that's kept us so warm actually does a decent job of blunting this trough and keeping the coldest air pinned up in the Upper Midwest. We *could* be even colder if the upper pattern were a little different! Speaking of that upper pattern, it settles into something zonal, or weakly ridgy for the mid to late week, so we still expect some fair weather with a slow, gradual warmup through the week. Model guidance still points to some sort of weak upper shortwave trough moving through towards the end of the week, so we may see another chance for some showers then. && .AVIATION... (12Z TAF Issuance) Issued at 516 AM CST Sat Dec 27 2025 Elevated winds overnight have prevented dense fog from developing, but some patches of reduced visibilities will remain possible through 15Z. As a result, low cloud ceilings are the main impact with MVFR to LIFR ceilings across the region. Surprisingly enough though, VFR conditions prevail along the coast and will likely prevail through tonight. Elsewhere, ceilings will gradually lift through the late morning hours with VFR conditions returning across the area by 20Z. Southerly to south-southwesterly winds around 10-15 kt with intermittent gusts around 20 kt will prevail throughout the day. Another round of MVFR to IFR ceilings are expected tonight into Sunday morning. Winds look to remain elevated once again, so ceilings are expected to be the main impact once again rather than fog. Batiste && .MARINE... Issued at 1158 PM CST Fri Dec 26 2025 For the time being, the environment remains generally supportive of sea fog development, though the south to southwest winds now in place should make any fog development less widespread and more transient. The peak time for fog will remain overnight into the morning hours. While this is a welcome development for marine interests, it's worth noting the potential for fog will not be fully over until a strong cold front pushes offshore late Sunday night. Along with some scattered showers and an isolated thunderstorm, there will be strong winds and building seas in its wake through Monday. Confidence continues to increase in gale conditions, particularly on the Gulf waters, but potentially also the bays, so a Gale Watch has been issued to cover the most likely window for gale conditions Sunday night and Monday. The NBM probability of the strongest winds and wind gusts reaching gale at any point on Monday is virtually 100 percent on the Gulf, though it's worth mentioning that verifying this would only require one single wind measurement. The probability of gale winds and gusts at a given time are lower, topping out at 30 and 50 percent, respectively. Of course, that can be misleadingly low because it requires a wind of that speed at that exact time! But, taken together, there is clearly a strong signal for gale conditions on the Gulf for 12-18 hours and I have every expectation the watch will eventually become a warning on the Gulf with this much confidence. Indeed, there is even a portion of the coastal Gulf waters with a low (roughly 10 percent) chance of seeing a sustained storm force wind at some point on Monday. This is not to say that storm conditions are expected by any means - a 10 percent chance of one single sustained wind that high does not a storm make - but does serve to enhance the confidence in gale conditions. The potential for gales on the bays may not be quite as high, but still justifies a need for a watch at this time. On the bays, the potential for gale winds at a specific time tops out Monday morning at 30-40 percent for gusts, and 20-25 percent for sustained. But again, that requires gales at that specific time! Taking the broader view of a gale force wind at any point on Monday, and those probabilities exceed 85 percent for gusts and 60 percent for sustained winds, with better odds on Matagorda Bay than Galveston Bay. With the thinking that a somewhat fuzzy view of "A Gale" is something of a blend of those two outcomes, it surely seems we meet the threshold of "about as likely as not" to justify a watch. Even if the data ultimately supports only a small craft advisory over a gale warning, conditions on the bays will likely be near that gale threshold. && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 82 66 81 41 / 0 0 0 30 Houston (IAH) 82 66 83 47 / 0 0 0 50 Galveston (GLS) 74 66 74 50 / 0 0 10 60 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...None. GM...Dense Fog Advisory until 10 AM CST this morning for GMZ330. Gale Watch from late Sunday night through Monday afternoon for GMZ330-335-350-355-370-375. && $$ DISCUSSION...Luchs AVIATION...Batiste MARINE...Luchs