000
FXUS64 KHGX 100040
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
640 PM CST Sat Dec 9 2023

...New AVIATION...

.SHORT TERM...
(This evening through Sunday Night)
Issued at 224 PM CST Sat Dec 9 2023

The cold front is expected to be near the coastal locations this
evening and move across the Gulf waters early tonight. A few
showers and possible isolated thunderstorms may still occur
near/along the front early this evening, although the cap is
helping inhibit a lot of the shower development. What is most
likely to occur with this front however, is strong gusty
northerly winds developing right behind it. Many inland portions
will see sustained winds of around 15 to 20 mph with gusts up to
30 mph early tonight into early Sunday morning. For locations
along the immediate coast and Barrier Islands, sustained winds
could range between 25 to 30 mph with gusts up to around 40 mph at
times. A Wind Advisory has been issued for the Barrier Islands
and will be in effect from 11 PM tonight through Sunday morning.
Thus, make sure you have light objects, decorations and
inflatables stored or secured correctly.

Dry and cool airmass will also filter in after the frontal
passage, decreasing our temperatures by around 20 degrees. The
lows overnight into early Sunday morning will dip quick and drop
into the upper 30s to low 40s along the Brazos Valley and Piney
Woods region and the low to upper 40s elsewhere.

A beautiful but somewhat breezy day is in store on Sunday with
mostly sunny skies and highs in the mid to upper 50s areawide. CAA
will bring down the lows on Sunday night to early Monday morning
even further and areas over the Piney Woods region could have lows
in the upper 20s to low 30s. For several inland portions, the lows
could be near freezing and will have to be monitored for a
possible Freeze Watch. Areas in and around the Houston Metro will
have lows closer to the mid to upper 30s, while the coastal lows
will range in the upper 30s to low 40s.

Cotto (24)

&&

.LONG TERM...
(Monday through next Friday)
Issued at 224 PM CST Sat Dec 9 2023

The long term starts good and chilly Monday morning. The highest
likelihood for sub-freezing temperatures roughly maps over the
portion of the area that has already seen freezing temps already
this season, along the northern and eastern edges of the forecast
area. That said, a good push of post-frontal cold advection after
the front paired with some really good radiational cooling potential
Sunday night means folks as far south as Bay City have at least a
realistic potential of starting Monday from the freezing mark. How
far south freezing temps go by Monday morning will likely be a point
of focus through the weekend.

For those who aren`t fans of chilly weather, take heart in that
Monday morning looks to be the depths of how cold it will get this
week. The high pressure center that should be overhead to set up
such a cold morning will continue drifting eastward, and we should
be looking to see winds veer easterly enough to get at least a
partial Gulf connection, boosting humidity, and ultimately setting
us up for a slow warmup. Now, it`s not going to get *that*
warm...we`re getting a mostly sunny sky in *December*, and a switch
from cold advection to return flow is *partial*...so don`t get too
excited, hot weather fans. I`ve only got Monday highs getting to
around or just on the cool side of climatological average. Of
course, with less impressive conditions for cooling and modestly
higher dewpoints keeping up the temperature floor, Monday night
looks chilly, but not as chilly as the previous.
Again, I`ve got somewhere around the averages for this time of year.
The warmup continues on Tuesday, with highs pushing a little bit
above average into the upper 60s to around 70 degrees.

This time of year, we are more significantly influenced by the
northern stream pattern, and so you`d be forgiven if you look at the
next trough/low pairing moving through that pattern getting hemmed
up in Canada followed by another big high settling into the eastern
US and think "Hey, looks like we`ll just keep on with more of the
same for the rest of the week!" And, if you were in much of the
eastern half of the country, that may not be the worst thought. For
us, on the southwestern fringe of the big high pressure center
though, things get a bit of a complication.

See, while northern stream troughs aren`t getting out of Canada in
this timeframe, we`re looking for a messy little disorganized trough
in the southern stream push its way into the western Gulf of Mexico.
It`s not a lot to look at, but guidance seems pretty confident that
it`ll be enough to spin up a weak surface trough over the Gulf. Its
main impact will be to increase clouds and deform the wind field.
The clouds should help constrain the diurnal temperature range a
bit, keeping highs down a little and holding highs up some. The wind
shift will be a bit mixed. With winds backing more to northeasterly,
this should keep things dry in the east. Meanwhile, look for
moisture to build down closer to that trough, and to see some rain
chances begin to sneak in the southwestern corner of our area. This
should mainly affect the Gulf waters off Matagorda Bay. But, I`ve
got some slight chance PoPs creeping onshore late Wednesday/early
Thursday.

Those rain chances continue to spread in from the west late in the
week, as we see stronger onshore flow resume in the wake of that
midweek trough and in advance of the next cold front. As that front
swoops in at the end of the week, we`ll see our next good area-wide
chance for rain, and a new jab of colder air.

&&

.AVIATION...
(00Z TAF Issuance)
Issued at 636 PM CST Sat Dec 9 2023

Band of SHRA and TSRA is along the cold front. It is near HOU now
and will reach the coast around 2Z. Winds behind the front are
from the NW at generally 15g25kt inland, but near the coast will
see gusts around 34 kts later on this eve. Expect mid/high clouds
to move east of the area later tonight. Gusty N/NW winds will
continue through tomorrow.

Wood

&&

.MARINE...
Issued at 224 PM CST Sat Dec 9 2023

Moderate onshore winds prevail this afternoon, but only until a cold
front sweeps across the waters this evening. Expect winds to switch
around to northwesterly, and become strong and gusty overnight into
Sunday. A gale warning remains in effect from 9 pm through noon
tomorrow. Expect winds to peak in the late night hours tonight, with
maximum wind speeds in the 30 to 35 kt range and gusts 40-45 knots.
Seas will lag behind the winds a bit, peaking early Sunday morning.
The highest seas around 60 nm out may reach to around 13 feet. In
the bays, the gusty northwest winds will result in abnormally low
water levels at times of low tide, and so a low water advisory is
out for Sunday.

Winds subside tomorrow night, gradually becoming more northeasterly
by Monday morning and easterly to southeasterly through the day
Monday at light to moderate speeds. The development of a weak
surface trough over the Gulf next week will result in winds
increasing and becoming more east to northeasterly for the midweek.
Depending on how much this trough develops, a need for small craft
advisories may emerge at this time.

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)  42  57  32  62 /  10   0   0   0
Houston (IAH)  46  58  35  62 /  20   0   0   0
Galveston (GLS)  49  58  44  62 /  50   0   0   0

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...Wind Advisory from 11 PM this evening to 9 AM CST Sunday for
     TXZ436>439.

GM...Gale Warning until noon CST Sunday for GMZ330-335-350-355-370-
     375.

     Low Water Advisory from 3 AM to 3 PM CST Sunday for GMZ330-335.

&&

$$

SHORT TERM...24
LONG TERM....Luchs
AVIATION...Wood
MARINE...Luchs