FXUS64 KHGX 090721 AFDHGX Area Forecast Discussion National Weather Service Houston/Galveston TX 121 AM CST Sun Nov 9 2025 ...New UPDATE, DISCUSSION, MARINE, FIRE WEATHER... .KEY MESSAGES... - Cautious travel will again be required in Brazoria and Matagorda counties, where a dense fog advisory is in place. Dense fog with visibility dropping to a quarter-mile or less is cropping up tonight before the anticipated cold front arrives. - The awaited cold front will pass through the area this morning, quickly followed by gusty winds and colder, much drier air. Critical fire weather conditions are anticipated and have resulted in the issuance of a red flag warning for this afternoon, and a continuing fire weather watch for Monday. A wind advisory is in place for where the strongest post-frontal winds are expected around Matagorda Bay and along Gulf islands and peninsulas. - Some locations well north of the Houston metro could have their first light freeze of the season tonight into Monday morning and/or Monday night into Tuesday morning. - Hazardous marine conditions are expected Sunday into Monday. A small craft advisory will lead into a gale warning later this morning for the coastal Gulf waters. A Small Craft Advisory is in effect for the Bays from the pre-dawn hours through late Sunday night. Additionally, the strong north winds will generate low water conditions in the bays, particularly Galveston Bay - a low water advisory is in effect for the Sunday and Monday low tide cycles. && .UPDATE... Issued at 1215 AM CST Sun Nov 9 2025 A flash flood watch has been issued near the Carter Lake Dam and portions of Dabbs Creek. Polk County Emergency Management has determined that the dam has been compromised, and asked for evacuations of the community downstream of the dam as they evaluate and resolve the situation. This watch may be upgraded to a warning if the evolving situation warrants. Residents should listen to local officials for the latest information on the situation and heed their advice. && .DISCUSSION... Issued at 121 AM CST Sun Nov 9 2025 There is...a lot going on with our long-anticipated cold front. Normally, I tend to write my AFD to flow with the forecast roughly with linear time. The long (well, longer than usual) parts kinda hint at what's most important. Tonight I fear that approach, or linear time itself, is a mistake. For this AFD, we're going to break things down by the different weather occurrences that pose their own unique hazards in their own right. Fire Weather - Red Flag Warning (today) and Fire Weather Watch (tomorrow) - There's a whole section of this below, so just the big stuff here. Despite the surge of dry air coming in on strong north winds, there is some question as to how well the ingredients for a fire weather threat will line up. Today will be the windier day, and critically dry. The limiting factor here may be fuels that are not yet in a critical condition, thanks to rain over the past couple of weeks. However, given the long-term dry conditions, fuels should dry effectively, and so we have enough confidence to issue a red flag warning for today. Most at risk will be areas with dense grassy areas, as those fine fuels will respond most quickly to the surge of dry air. Tomorrow looks even drier than today, and fuels will have more time in this airmass to become drier themselves. Here, while we start the day with some stronger winds, they will be gradually diminishing through the day. Due to uncertainty of getting the proper overlap of high winds and low RH, we opted not to upgrade the fire weather watch for Monday just yet. Marine Conditions - Small Craft Advisory (bays) and Gale Warning (Gulf); Low Water Advisory (Galveston Bay) - Winds will turn northerly and begin to crank up after the front pushes offshore, with conditions dangerous to small craft developing quickly. Late in the morning, towards mid- day, we'll look for gale conditions to emerge over the Gulf, while small craft conditions remain over the Bays. Strong north winds should continue through the night thanks to the tight pressure gradient and cold air over warmer waters. Though ensemble probabilities for gale conditions are lower than desired for a gale warning, gusts to the gale threshold were observed upstream earlier today. And if we can manage gale gusts over land, it seems likely that gale conditions are likely over the waters, which will be more supportive of strong winds. These winds will also force low water on both Matagorda and Galveston bays, but look particularly troublesome for Galveston Bay. Low water, around or more than a foot below MLLW, looks likely across the Bay at today's low tide, as it lines up well with the strengthening north winds. PETSS modeling also suggests that similarly low water will hold in the upper portions of the bay and Houston Ship Channel through Monday's low tide cycle as well. Windy conditions over land - Wind Advisory (Matagorda Bay area, area islands and peninsulas) - While related to the fire weather conditions above, we also have a separate wind advisory for a smaller portion of the area where winds look to be the strongest - with sustained winds up to around 25 mph, and gusts to around 35 or even 40 mph. One area is in what tends to be one of the windier spots in our forecast area - the Matagorda Bay area, in Jackson, Wharton, and Matagorda counties. The prime stretch for these winds will be this afternoon. Another spot to watch will be right on the immediate Gulf coast, the islands and peninsulas that make up the land beyond the Intracoastal Waterway. With most of this area getting a long fetch down the bays, they should see winds bridging that gap between the small craft advisories on the bays and the gales on the Gulf. The advisory for this area continues through the night, ending with the Gulf early Monday morning. Dense Fog - Dense Fog Advisory (Matagorda and Brazoria counties through 6 am - Yes, with all this talk about wind, we also still are dealing with fog! At the coast, dense fog is developing in the moist environment ahead of the front. While this should clear up quickly once the front passes and the dry airmass surges in on strengthening winds, overnight travelers near the coast will need to be ready for dramatic drops in visibility. Cold Temperatures - no current watches, warnings, or advisories - Yes, winter is indeed coming. And with this surge of colder air, we need to start considering our first potential for a light freeze, and for wind chills. And while we definitely need to consider this, it is worth noting that we are kind of dodging a bullet here in SE Texas in spite off all this frontal commotion. Confidence is now quite high that the coldest air misses us to the east, with the deepest of the cold pool working through the Mid- South to the Southeast US, and we just get a glancing blow. It is enough of a blow that we may yet need a freeze warning for the northernmost part of our area. I gave strong consideration to a freeze warning for Houston, Madison, and Trinity counties tonight. However, the freezing temps do not look widespread or for more than a brief touch around dawn to push me over the edge. However, a short fuse warning may be needed if it becomes apparent that those areas will see a stronger cold impact. NBM probabilities of a light freeze in that area are in the 30-50 percent range. Not quite enough for a warning, but it will be close and those localized cold spots here and there could well get themselves an isolated freeze spot. If your pets, plants, and/or people are in one of those cold spots, it wouldn't be a bad idea to take precautions regardless of whether there is a warning or not. Tomorrow night appears to have a little better potential. We'll have the double-edged sword of winds dying down. Yes, it stops pumping in cold air, but it also allows for better radiational cooling overnight. As a result, those NBM probabilities for freezing temps rises more into a 50-70 percent range well north of the Houston metro. But some non-zero probability of freezing temps exists all the way down to I-10 if you're outside of the Houston urban heat island. Though the deterministic guidance currently indicates temps most likely hanging in the middle 30s inland to the middle 40s at the coast, this will be something we need to keep an eye on. Though this episode of cold temps will be sharp, it also looks brief. Again, with this being only a glancing blow of the arctic cold pool, we should see the worst of things move off quickly, and have onshore flow return Tuesday in order to start modifying and replacing the airmass with warmer, more humid Gulf air. Things may warm back up so quickly, in fact, that we may be back to looking at high temps around 80 degrees as soon as Wednesday! Temperature whiplash indeed! Rain - yeah, still nothing. No PoPs enter the forecast until a week from now, once we get a more prolonged stretch of onshore flow bringing deeper moisture back to the area. && .AVIATION... (00Z TAF Issuance) Issued at 508 PM CST Sat Nov 8 2025 Strong cold front is moving through the DFW area, and should reach SE Texas overnight/early Sunday morning, bringing strong, gusty northerly winds. However, prior to the arrival of the front, patchy dense fog is likely to develop near LBX and surrounding coastal areas, brining IFR-LIFR conditions. Once the front pushes through, a few spots could see gusts reach 34 knots or greater, and such wind gusts have already been observed upstream. Some LLWS may be present behind the front during the pre-dawn hours of Sunday. Strong northerly winds should slowly ease down through Sunday night. 03 && .MARINE... Issued at 121 AM CST Sun Nov 9 2025 A cold front makings its way across Texas is expected to pass off the coast between 2am-6am Sunday. Expect strong north winds and building seas to arrive shortly after the front passes. There is only a slight chance of showers and thunderstorms over the Gulf waters along the front. Small Craft Advisory conditions are expected on all area waters for much of this morning, becoming gales on the Gulf towards mid- day and through the night. The strong north winds will also generate low water conditions late Sunday and Monday on both Galveston Bay and Matagorda Bay, with more severe low water conditions anticipated on Galveston Bay, where a low water advisory has been issued. These conditions are expected to be an issue at low tide on Sunday, but also in upper portions of the bay and the Houston Ship Channel through Monday's low tide cycle as well. && .FIRE WEATHER... Issued at 121 AM CST Sun Nov 9 2025 Another window for patchy fog near the coast will be in the pre- dawn hours ahead of an approaching cold front. This front will push through the region in the overnight and early morning hours, bringing critically dry air, colder temperatures, and strong, gusty winds in its wake. Critical fire weather conditions are expected Sunday and Monday due to the dry air and gusty winds, prompting a red flag warning across Southeast Texas as any new fires could spread rapidly in this environment. At greatest risk will be areas of dense, grassy fuels, which will respond most quickly to the surge of dry air. Winds will begin to diminish Monday, but humidity will be even lower and fuels will have additional time to dry. A Fire Weather Watch continues across the area Monday, as there may be a window in which critical fire weather conditions materialize again. Continue to obey all local burn bans. && .FIRE WEATHER... Issued at 121 AM CST Sun Nov 9 2025 Elevated fire weather conditions are expected on Sunday and Monday as gusty northerly winds prevail in the wake of a strong cold front that pushes through late Saturday night/early Sunday morning. Drier air behind the front will lead to minimum RH values in the 25-35% range on Sunday and 15-25% range on Monday. While the driest conditions hold off until Monday, winds will be the strongest on Sunday with the strongest sustained winds around 20 mph and gusts around 30 mph. Winds on Monday will start out gusty, but gradually subside throughout the day. A couple rain events over the past couple of weeks will help temper the threat posed by the dry and windy conditions, particularly in the northeast towards the Piney Woods. Data from the Texas A&M Forest Service indicates above, but near normal, fuel conditions becoming more unusually dry as the drier airmass sets in. A Fire Weather Watch is in effect for all of Southeast Texas Sunday and Monday. Regardless of whether a warning is issued or not, fire weather conditions will be near critical to critical- it will be important to use extreme caution with flame and sparks, as well as obey all burn restrictions and burn bans to minimize the ignition of new fires. Bailey/Luchs && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 67 35 58 36 / 0 0 0 0 Houston (IAH) 72 40 60 39 / 0 0 0 0 Galveston (GLS) 73 47 60 52 / 0 0 0 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...Red Flag Warning from 9 AM this morning to 6 PM CST this evening for TXZ163-164-176>179-195>200-210>214-226-227-235>238-300- 313-335>338-436>439. Fire Weather Watch from this evening through Monday afternoon for TXZ163-164-176>179-195>200-210>214-226-227-235>238-300- 313-335>338-436>439. Wind Advisory from 4 AM early this morning to 6 PM CST this evening for TXZ226-235-236-335-336. Dense Fog Advisory until 6 AM CST early this morning for TXZ236- 237-336-337. Wind Advisory from 4 AM early this morning to 6 AM CST Monday for TXZ436>439. GM...Small Craft Advisory from 4 AM early this morning to 6 AM CST Monday for GMZ330-335. Low Water Advisory from 8 AM this morning to midnight CST Monday night for GMZ335. Small Craft Advisory from 4 AM to 8 AM CST this morning for GMZ350-355-370-375. Gale Warning from 8 AM this morning to 6 AM CST Monday for GMZ350-355-370-375. && $$ DISCUSSION...Luchs AVIATION...03 MARINE...Luchs