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645
FXUS64 KHGX 192307
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
507 PM CST Fri Dec 19 2025

...New AVIATION...

.KEY MESSAGES...

- Long stretch of warm weather with temperatures 10-20 degrees
  above normal.

- Daily chances for sea fog across the bays and coastal areas,
  especially during the dusk-dawn hours.

&&

.DISCUSSION...
Issued at 1241 PM CST Fri Dec 19 2025

High pressure pushes east of the state today, bringing onshore flow
back for tonight. At the same time, midlevel ridging over Baja
California will gradually migrate eastward over the next several
days. This will leave us in a persistent onshore flow pattern with
high pressure aloft for the holidays. Heights within the ridge are
anticipated to reach 586-590 dam, which is particularly high for
December. Saturday morning will be the coldest period in the
forecast with lows in the 40s/50s. We may see a weak cold front push
into the northern half of our cwa on Sunday, though current guidance
shows it stalling out and subsequently lifting north, keeping
onshore flow unbroken near the coast. May see some showers and
possibly a few storms during this period as the front approaches,
though mostly isolated to scattered activity. Either way, from
Saturday onwards we`re expecting highs in the 70s/lower 80s with
lows in the upper 50s/lower 60s. This puts temperatures around 10-20
degrees above normal for December.

Water temperatures are currently in the upper 50s/lower 60s across
the nearshore waters/bays, and given the uninterrupted stretch of
onshore flow, it is likely that we`ll see fog on the daily in some
capacity with sea fog being a particular concern for mariners.
Radiation fog will be more dominant tonight with only isolated
chances for some patchy sea fog across the upper bays/houston ship
channel. Saturday and Sunday into early Monday will likely see the
worst of the sea fog, as this is when the dewpoint and water
temperature difference is largest. We`ll likely see the lowest
visibilities during this dusk-dawn period with patches to areas of
sea fog in the coastal waters and bays filling inland with radiation
fog as the night progresses. As for when this fog ends... that`s a
bit tricker to answer. There`s no large wx systems on the horizon
that`ll wipe out the sea fog/radiation fog in one-go (even 240 hours
out in the GFS). This means that we`ll have to wait for water
temperatures to gradually warm up (from advection & downwelling) on
their own. RTOFS still has around a 1-4 degree difference between
the dewpoints and water temperatures by Monday evening. SREF still
shows a signal for sea fog at this point, though weaker, so perhaps
visibility reductions from fog won`t be as potent heading into
Tuesday morning. Either way, this all hinges on the speed at which
water temperatures warm these next few days.

At this point, it`s safe to say that Christmas won`t be white... at
least not like the ones you use to know. Could see some morning fog
and perhaps some see fog along the coast during the late evening and
early morning periods as we remain in this onshore flow pattern
under the ridge.

03

&&

.AVIATION...
(00Z TAF Issuance)
Issued at 507 PM CST Fri Dec 19 2025

VFR conditions and light southerly to southeasterly winds will
prevail going into the evening hours with a trend for winds to
become light and variable overnight. Model guidance is fairly
consistent on a window for MVFR to potentially IFR ceilings on
Saturday morning generally in the 12Z-16Z timeframe. This is more
likely for northern and western terminals, but there is enough
probability for it to extend to the Houston metro terminals that a
TEMPO has been added. There is also potential for reduced
visibility due to patchy fog in that same timeframe as well, but
this has only been hinted at for CXO and SGR for now. Wind speeds
pick up out of south-southwest by Saturday afternoon with 10-15 kt
sustained winds and gusts in the 20-25 kt range through sunset.

Looking ahead to Saturday night/Sunday morning, confidence is
increasing on widespread IFR/MVFR ceilings and visibilities with
areas of dense fog anticipated especially near and south of I-10.

Batiste

&&

.MARINE...
Issued at 1241 PM CST Fri Dec 19 2025

Winds will shift east this afternoon then southeasterly later
tonight. Isolated pockets of fog may develop in the upper
bays/houston ship channel overnight into early Saturday. A weak cold
front is expected to push into SE Texas on Sunday but stall out
before reaching the coast, though some isolated to scattered
showers/storms could develop along/ahead of it. With any breaks in
rainfall, we`ll have to watch out for patches to areas of sea fog.
Sea fog will continue to be a daily risk into next week, especially
during the dusk-dawn hours. There are no significant fronts or
weather systems on the horizon that will clear out sea fog, so we`ll
have to wait for water temperatures to gradually rise enough to put
an end to sea fog.

03

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)  46  77  62  75 /   0   0   0   0
Houston (IAH)  48  79  66  79 /   0   0   0  20
Galveston (GLS)  57  71  64  72 /   0   0  10  30

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&

$$

DISCUSSION...03
AVIATION...Batiste
MARINE...03

NWS HGX Office Area Forecast Discussion