FXUS64 KHGX 212307 AFDHGX Area Forecast Discussion National Weather Service Houston/Galveston TX 507 PM CST Sun Dec 21 2025 ...New AVIATION... .KEY MESSAGES... - Long stretch of unseasonably warm weather with temperatures 10-20 degrees above normal. These temperatures will be near daily record high values, and a few records may fall throughout the week. - 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 Monday morning. && .DISCUSSION... Issued at 1204 PM CST Sun Dec 21 2025 Onshore flow continues while a midlevel ridge over Baja California/Western Mexico gradually migrates eastward towards Texas. Heights within this ridge are still anticipated to reach 586-590 dam, which is particularly high for December. A weak backdoor cold front has stalled out over the Brazos Valley and should lift north heading into next week. Some spares showers have developed, mainly near the coast, but on the whole activity is low. In all, we're still expecting highs in the 70s/lower 80s with lows in the upper 50s/lower 60s. This still puts temperatures around 10-20 degrees above normal for December. Water temperatures have warmed, but are still in the lower 60s across the nearshore waters/bays while upper 60s/lower 70s dewpoints cover the majority of SE Texas. We saw large areas of dense fog and sea fog earlier this morning, and while much of it has cleared, some isolated lingering pockets may still be in place. As already mentioned, there's really no weather systems on the horizon that will disrupt onshore flow (at least within the next 7 days... could see a FROPA just beyond that). As a result, sea fog (and in part inland radiation fog) will be a daily occurrence until water temperatures can climb up to dewpoint temperatures. Tonight into Monday morning will likely see the greatest impacts from widespread sea fog due to the high dewpoint depression compared to water temps, along with an east/southeasterly wind shift early in the morning. Would not be surprised if some pockets of sea fog persist throughout the whole day without clearing in some spots. Monday night into Tuesday morning will probably see another period of fairly low visibilities from fog and sea fog as models show higher dewpoints that previously forecasted, along with higher SREF and HREF probabilities for dense fog. As water temperatures warm with each passing day, the extend, intensity and duration of sea fog should decrease. Christmas eve and Christmas day will probably see some pockets of fog, though perhaps not as dense/widespread as days prior. Still, this fog could technically give folks a "white" Christmas if your definition of such is very forgiving and ignores PType entirely. Warm and humid weather continues through Friday into the weekend. Long range models have the next cold front *tentatively* penciled in for around Sunday, which should give us at least one more cool-down before the end of the year. 03 && .AVIATION... (00Z TAF Issuance) Issued at 507 PM CST Sun Dec 21 2025 VFR conditions and light winds persist for most locations, but LIFR conditions are ongoing at GLS due to sea fog. Widespread IFR/LIFR conditions are expected eventually overnight, but the timing of when this occurs on a per-terminal basis depends on their proximity to a weak frontal boundary. As of 23Z/Sunday, the front is currently near CXO and is not anticipated to go any further south than potentially IAH. As a result, the southern terminals will see decreasing ceilings/visibilites a few hours quicker than the northern terminals. With winds being much lighter tonight, dense fog is expected to pose more of an impact to most terminals especially in the 09Z-15Z timeframe. Outside of GLS, visibilities will improve by 16Z with MVFR ceilings lingering till 18Z-20Z. Sea fog is expected to linger around GLS throughout the day, so IFR/LIFR conditions prevail for the entire TAF period. High resolution model guidance also indicated to the potential for isolated showers Monday morning and into the afternoon, but the probabilities are too low to include a mention of it in any of the TAFs at the moment. Batiste && .MARINE... Issued at 1204 PM CST Sun Dec 21 2025 Visibility has improved this afternoon, though pockets of sea fog are lingering in portions of the bays and nearshore Gulf waters. Some pockets of dense fog persist, though even if they clear over the next few hours, dense sea fog will likely fill back in this evening into Monday morning. The potential for overnight and morning fog will need to be monitored each night into the first half of next week. Beyond that, conditions will be warm and relatively calm with light southerly winds and seas 3 feet or less. 03 && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 58 76 64 79 / 0 0 0 0 Houston (IAH) 64 79 65 79 / 10 10 0 0 Galveston (GLS) 67 74 63 74 / 10 10 10 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...None. GM...Dense Fog Advisory until 10 AM CST Monday for GMZ330-335-350-355. && $$ DISCUSSION...03 AVIATION...Batiste MARINE...03