483
FXUS64 KHGX 081755
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1155 AM CST Wed Jan 8 2025

...New AVIATION...

.SHORT TERM...
(Today through Thursday Night)
Issued at 325 AM CST Wed Jan 8 2025

Overnight lows tonight are running several degrees higher than
those of yesterday, thanks to a loss of cold advection and
increasing cloud cover across portions of the area that has
inhibited radiative cooling. Still, many stations as of 3 AM CT
are reporting wind chill values in the 20s and a few stations are
showing temperature values below freezing. As such, it`ll be
another morning where you won`t want to forget those extra layers
as you head out the door.

For Wednesday, strong surface high pressure over the Southern
Plains along with modest but persistent northerly winds will
supply us with another cold afternoon. Increasing midlevel
moisture and resultant cloud cover will remain on an upward trend,
which should suppress highs somewhat compared to those of
yesterday. Most inland locations should remain confined to the
lower/mid 40s this afternoon, with the immediate coast perhaps
breaking into the upper 40s at times.

This synoptic pattern remains on track to begin to break down late
on Wednesday, albeit still a bit more slowly than previously
expected. Nonetheless, we will see an increase in precipitation
chances as a strong upper trough approaches from the west and an
associated developing surface low over the TX coastal bend drifts
towards the SE TX coast. Rainfall chances begin to pick up by
Thursday morning, and while we still anticipate a low chance of
mixed precip/freezing rain across the far northern zones (i.e.
Houston County, Trinity County) the trend of slightly warmer
temperatures continues to limit this chance significantly. Latest
NBM probabilistic guidance continues to shift higher winter
precip chances northward, and model soundings indicate a fairly
weak signal for freezing rain. Still, this will be something to
monitor as any shifts in p-type will be subject to relatively
small fluctuations in temperature.

The prospect of locally heavy downpours enters the forecast as we
approach Thursday afternoon and evening and the aforementioned
surface low tracks towards the coastline. Rainfall totals through
mid- Friday indicate widespread totals of 2-3" inland and 3-4"
along the immediate coast, with some locally higher amounts
possible (4-6") where the strongest storms set up. This could
presumably lead to some instances of street flooding late on
Thursday into early Friday, and as such it will remain important
to monitor road conditions and pay attention to the latest
forecast information. Expect a fairly sharp temperature gradient
on Thursday given the approach of the surface low near the coast,
with locations south of I-10 reading the 50s to near 60 and
locations north of I-10 generally sitting in the mid/lower 40s.

Cady

&&

.LONG TERM...
(Friday through Tuesday)
Issued at 325 AM CST Wed Jan 8 2025

Although models are in better agreement on the track of the coastal
low for Thursday, there is a bit of a delay again on the timing of
it (just by a few hours). Yesterday, the low was expected to tack
into the Matagorda Bay region sometime around mid/late afternoon on
Thursday. However, today`s latest model runs (HiRes and Global
models) indicate that the low arrives the Matagorda Bay region
sometime between the evening to early night hours and continues into
the LA coasts early Friday. The timing for the moderate to heavy
rainfall period is also delayed, with the higher rain chances now
extending into the overnight to early morning hours on Friday. This
delay then bleeds into Friday morning`s forecast, which continues to
carry 30-60% PoPs through at least the late morning hours. Now,
there are some inconsistencies on the models about when and how
quick the cold dry airmass behind the low pushes across Southeast
TX. It may be fast enough that most of Southeast TX could be rain
free by the mid morning hours on Friday. For this issuance, however,
I have rain tapering off from northwest to southeast during the mid
to late morning hours. For the rest of the day Friday, conditions
will be breezy and skies will remain cloudy. The highs are expected
to be in the low 40s over the Brazos Valley and Piney Woods region
and the mid to upper 40s elsewhere, but winds will make temperatures
feel as if its in the mid 30s to low 40s. So make sure to bundle up
well!

CAA will continue Friday night, which will bring our low
temperatures back to near or below freezing for much of Southeast
TX. The lows are expected to drop into the low to mid 20s for the
Brazos Valley and Piney Woods, the upper 20s to low 30s for the rest
of the inland portions, and the mid to upper 30s for the coasts.
Luckily, sunny skies will help warm up the day on Saturday and highs
are expected to rise into the low 50s. Another cold night is on tap
Saturday night as lows dip reach the low to mid 30s north of I-10
and the mid to upper 30s near and south of I-10. The warming trend
will continue into Sunday with highs in the upper 50s to low 60s
areawide. Cold dry air will once again move into Southeast TX early
next week, which could keep our highs in the 50s and our lows in the
30s and 40s range.

24

&&

.AVIATION...
(18Z TAF Issuance)
Issued at 1143 AM CST Wed Jan 8 2025

VFR conditions continue through the 18Z period for terminals north
of IAH. IAH/HOU/GLS/SGR/LBX all expected to remain VFR through the
end of the overnight hours. For IAH and south, showers will begin
to move into the area around 12Z and CIGs and VSBYs will
deteriorate to MVFR/IFR levels around the 15-17Z time frame as
moderate to periods of heavy rainfall impact the area. Expect
SHRA/RA to continue and spread northward through the day. Winds
will generally be light and variable tonight through overnight
hours, becoming more ENE at around 10-15 kts during the day
Thursday.


&&

.MARINE...
Issued at 325 AM CST Wed Jan 8 2025

A Low Water Advisory and a Small Craft Advisory remain in effect
this morning due to moderate to strong northeast winds. Winds will
relax this afternoon and remain moderate through early Thursday.
Winds are expected to turn east and strengthen quickly Thursday
morning, as a coastal low makes its way into the low/mid TX coast.
Winds may reach Gale strength Thursday afternoon into Thursday night
as the low moves across the Upper TX coast. Periods of moderate to
heavy rainfall and seas of 7-11ft can be expected as well.
Advisories will be required and a Gale Warning may be warranted. A
Gale Watch could be issued later today.

The low is forecast to progress east into the LA coasts early Friday
and a cold dry airmass will push across the region in its wake.
Strong northwesterly winds are expected Friday, maintaining 6-11ft
seas and very rough bay waters. Winds and seas subside Friday night
with light variable winds expected on Saturday. Onshore flow returns
Sunday morning, but northeast winds may re-develop later on Sunday
and strengthen on Monday. Caution flags and/or Advisories may be
needed once again.

24

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)  45  33  41  35 /   0  10  90 100
Houston (IAH)  45  37  45  38 /   0   0  80 100
Galveston (GLS)  47  44  59  42 /   0   0  80 100

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...Small Craft Advisory until noon CST today for GMZ330-335-350-355-
     370-375.

     Low Water Advisory until noon CST today for GMZ335.

     Small Craft Should Exercise Caution through Thursday morning for
     GMZ350-355-370-375.

&&

$$

SHORT TERM...Cady
LONG TERM....Cotto
AVIATION...Adams
MARINE...Cotto