textproduct: Houston/Galveston

KEY MESSAGES

- Long stretch of unseasonably warm weather with temperatures 10-25 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 Friday morning.

- Last cold front of the year anticipated to move through the area on Sunday with colder weather slated for Monday.

DISCUSSION

Issued at 1231 PM CST Tue Dec 23 2025

Not much different from yesterday... same pattern continues with onshore flow at the surface and 586-588 dam midlevel ridge overhead. Anticipating temperatures 10-25 degrees above normal with highs in the 70s/lower 80s with lows in the 60s through Saturday. These temperatures will hit or break records at some locations.

Much of yesturday's analysis with regards to sea fog still applies with only a few differences. Water temperatures continue to warm. Around Matagorda bay Tw hovers around the upper 60s/lower 70s. At and east of Freeport, water temperatures remain in the mid/lower 60s. The Galveston Bay entrance (north Jetty) now sits at 61.7F, ~0.9F increase from yesterday (60.8F). Winds are firmly E this afternoon, likely advecting some cooler water temperatures into the area to limit the extend of warming. Dewpoints in the upper 60s/lower 70s dewpoints can still be observed across much of SE Texas. Inland fog wasn't as impressive this morning, though the coastal plains still got widespread sub 1/4 mile visibility from sea fog advecting inland. Patches of sea fog are looming over the nearshore waters (High Island-Freeport) this afternoon... and I would not be shocked if some of these dense patches hold on through the rest of the daytime.

NBM and short range model guidance now show higher confidence in dense sea fog beyond mid week across the coastal waters. Not too surprising that it's shifting course, as previously mentioned yesterday, there were several factors suggesting that model guidance was potentially underdoing the full extend of sea fog. First, RTOFS SST has water temperatures at the Galveston bay entrance at 62.4F while the north jetty (again) is showing 61.7F (~0.7F Difference). NBM Dewpoints for this same point are being sampled as 63F even though the Galveston ASOS is reading dewpoints at 69F. This drop in dewpoint stems from model/ensemble members in the NBM and their attempts to incorporate the effects of the cooler water temperatures. Again, it's import to keep this in mind when attempting the gauge the extend of sea fog, as they will make the Td/Tw gap appear smaller over these cooler spots. Bottom line, model guidance would suggest the difference in dewpoint/water temp to be around 0-2F, when in reality the gap is still around 7F in the coolest spots.

This evening into the morning of Christmas Eve will likely see fog return, widespread and dense over the waters, bays & coastal plains, becoming thinner areas/patches further inland. Fog will erode during the daytime again, but some pockets will loom over the nearshore waters and bays, especially in areas east of Freeport where the waters are coolest. Fog will roll back in again the night of Christmas Eve, resulting in a foggy Christmas morning for SE Texas. SREF, HREF, and REFS are all showing strong signals for fog during this period. Again this will primarily impact the coastal plains, though many areas south of US-59 will likely experience the tropical equivalent of a White Christmas.

Thursday night into Friday will most likely see another round of fog, though winds are expected to shift south/southwesterly early in the morning. This orientation is overall less favorable for sea fog, and pairing it with the slowly warming water temperatures, we should (hopefully) see the full extend & intensity of sea fog become more limited as we head into the weekend. The next cold front is currently forecasted to move through SE Texas on Sunday, producing showers/storms and providing one last cool-down before end of the year. This will bring a more definitive end to this current stretch of sea fog as strong northeasterly winds develop in the wake of the front.

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AVIATION

(12Z TAF Issuance) Issued at 516 AM CST Tue Dec 23 2025

Mainly a "rinse and repeat" TAF forecast for this issuance with LIFR-MVFR conditions early this morning due to low cloud decks as well as areas of patchy to dense fog (mainly over the southern portions of SE Texas). Fog is expected to burn off around 15Z and cigs will gradually rise throughout the day (possibly scattering out in the afternoon)...however, GLS/LBX will be slower to improve due to sea fog continuing over the bays and nearshore waters for much of the day. SE winds at 05-10 KTS today, relaxing to 5 KTS or less tonight. Another round of LIFR- MVFR cigs/vis expected tonight into Tue morning due to low decks and fog/sea fog.

Cotto

MARINE

Issued at 1231 PM CST Tue Dec 23 2025

Patchy fog will linger through the entire day near the bay entrances and nearshore waters, especially in areas east of Freeport. Any improvements later this afternoon will quickly end by the evening hours with areas of dense fog returning tonight into Wednesday morning. Sea fog will likely return nightly through at least Friday morning with some patches possible through the weekend. 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.

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PRELIMINARY POINT TEMPS/POPS

College Station (CLL) 65 79 63 79 / 0 0 0 0 Houston (IAH) 66 79 64 79 / 0 10 0 0 Galveston (GLS) 64 74 63 75 / 10 10 10 0

HGX WATCHES/WARNINGS/ADVISORIES

TX...None. GM...Dense Fog Advisory until noon CST Wednesday for GMZ355.