333
FXUS64 KHGX 091020
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
420 AM CST Sun Nov 9 2025

...New AVIATION...

.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 420 AM CST Sun Nov 9 2025

A non-convective Flash Flood Watch has been issued near the
Carter Lake Dam and portions of Dabbs Creek south of Camden in
northeastern Polk County. 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...
(12Z TAF Issuance)
Issued at 420 AM CST Sun Nov 9 2025

A cold front is pushing through Southeast Texas early this morning
with gusty northerly winds in its wake. Any lingering fog or low
ceilings will clear out over the next couple of hours as the front
pushes offshore. Northerly winds today will be sustained in the
15-20 kt range with 25-30 kt gusts (higher winds closer to the
coast). Elevated winds (10-15+ kt) stick around into late Sunday
night/early Monday morning. VFR conditions prevail throughout the
TAF period following the frontal passage.

Batiste

&&

.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.

&&

.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.

     Dense Fog Advisory until 6 AM CST early this morning for TXZ226-
     227-235>237-335>337.

     Wind Advisory until 6 PM CST this evening for TXZ226-235-236-335-
     336.

     Wind Advisory until 6 AM CST Monday for TXZ436>439.

GM...Small Craft Advisory until 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 until 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...Batiste
MARINE...Luchs