129
FXUS64 KHGX 241851
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1251 PM CST Mon Nov 24 2025

...New MESOSCALE UPDATE, DISCUSSION, MARINE...

.KEY MESSAGES...

- TORNADO WATCH in effect through 7 PM Tonight. Discrete storms
  capable of all severe hazards, including heavy rainfall as well,
  will be possible ahead and along a cold front.

- Cold front should slow as it approaches the Houston Metro late
  tonight with the severe/hydro threat diminishing as it slowly
  pushes off the coast Tuesday morning.

- A stronger, reinforcing front pushes through Wednesday morning,
  bringing cooler and drier conditions just in time for Thanksgiving.

&&

.MESOSCALE UPDATE...
Issued at 1158 AM CST Mon Nov 24 2025

TORNADO WATCH IN EFFECT UNTIL 7 PM TONIGHT

Already got a quick spinup on radar early this afternoon, so it
appears that severe weather threat is already underway. Currently
keeping a close eye on our west/northwestern counties where
instability is rather robust. CAMs were pinging this location
earlier in the 12z model run, though it`s destabilized rather
quickly. Mesoanalysis shows some 2000-2500 ML CAPE with LCL
heights under 750m. Decent shear on the whole though it and
helicity are strongest further to the northeast. May see a few
more spinups in this area with the current set of storms,
especially as they track northeasterly into better helicity and
shear.

We`ll probably lose some of this instability over the western
CWA as it`s worked over by the current storms... though there are
some gaps in coverage. One of these "Gaps" forming is around the
Brazos/Washington/Grimes area. Short-range model updates are
suggesting higher instability in this general area due to a gap
in storm coverage that already seems to be manifesting on
radar... so we could still see some severe wx develop in this
area. Otherwise, we`ll see the area of severe weather broadly
expand northeastward leading up the FROPA as instability builds
into this area with better dynamics and shear.

03

&&

.DISCUSSION...
Issued at 1158 AM CST Mon Nov 24 2025

Things are already kicking into high gear hear with storms
beginning to fire up ahead of the cold front. The current
environment shows PWs of 1.4-1.8 inches with model guidance
indicated the potential to pool up to 1.9-2.0 inches ahead of the
line. 300mb analysis showed ample omega north of the area with
the RAP/GFS/NAM all showing SE Texas getting clipped by some of
the stronger omega values as it tracks eastward with the upper
trough. LLJ around 25-30 knots peaking near 40 knots in CAM
models. On the whole, dynamics appear modest over the northern
half of our CWA, primarily over the Piney Woods area near areas
like Crockett & Livingston. Thermodynamics is a more interesting
story, which continue to trend upwards with RAP analysis
already 1500 J/KG of ML CAPE. More concerning is a rather
consistent signal in the CAMs pinging on a bullseye of elevated
CAPE in our west/northwestern counties, over 2500 J/KG with
respect to ML CAPE and nearing 3000 J/KG in for SFC/ML CAPE in
some models. Seems to come as a result of the area being plunged
deeper in the warm sector with moisture pooling in advance of the
FROPA... And before I could finish writing this discussion we had
out first TOR warning in place over this area... so my concerns
about this area appear to have been justified, especially now as
now SPC`s mesoanalysis is showing this deeper instability. Shear
is still as robust as it was several day prior with bulk shear of
30-50 knots. 100-200 m2/s2 1km SRH with 20-30 knots of 1km bulk
shear. LCL heights are also generally forecasted under 1500m with
a good swap of the area under 1000m throughout most of the
afternoon.

Seeing better agreement with timing too among models (at least
earlier in the forecast), showing the cold front enter the Brazos
Valley late in the afternoon, reaching College Station around 3-6PM.
CAMs become a bit more split later tonight as the front nears the
Houston Metro. Broadly it seems like it should slow and lose some of
it`s gusto (waning instability and being further removed from
stronger upper level dynamics), moving through the city around 9PM-
1AM... could be even later as hinted at by the FV3 and NAM. The
front should move offshore around 1AM-5AM, though again the FV3 is
dragging its feet, wanting to keep the front on dry land till
daybreak. Still is a very feasible outcome (and thus leaned
closer towards the FV3 with this forecast), but again in such a
scenario the line itself will be far less potent by that point, so
the severe/hydro concerns shouldn`t be prolongued either.

Main takeaway is that we`re expected strong to severe storms ahead
of and along an approaching cold front today & tonight. SE Texas is
under a Slight (2/5) to Marginal (1/5) Risk of Severe Weather and
Excessive Rainfall for today. These storms will be capable of
producing damaging winds, large hail, tornadoes and locally heavy
rainfall. The northern half of our CWA will be most at risk of these
severe storms. The threat of heavy rainfall is on the whole lower,
with the greatest risk much more confined to our north/northeastern
most counties, where locally higher rainfall totals up to around 4
inches could occur. Though, any training storms could still result
in some minor street flooding, especially in Urban areas/areas of
poor drainage (i.e. Houston Metro). With respect to timing, the
severe/rainfall threat has already begun. Storms on the whole
should become weaker late tonight with the severe/hydro threat
ending early Tuesday.

Rest of the forecast remains the same. An upper level low moving
through the Northern Plains should push a reinforcing cold front
through the area Wednesday morning. This will usher in cooler and
much more seasonable weather for Thanksgiving. Morning lows for the
holiday are forecasted to be in the 30s/upper 40s inland and 50s
near the coast. Daytime highs on Thanksgiving are anticipated to be
in the 60s/lower 70s. Conditions will also be dry too with no rain
expected. Heading into Friday, we`ll see onshore flow return and
temperatures/rain chances rise into the weekend. Hints of another
cold front remain on the horizon for Sunday into some time next week.

03

&&

.AVIATION...
(18Z TAF Issuance)
Issued at 1112 AM CST Mon Nov 24 2025

Scattered TSRA has already developed across the region,
warranting at least VCTS starting now for the TAFs north of I-10.
These storms are expected to mostly impact our northern TAFs (CLL,
UTS, and CXO) where there are TSRA TEMPO groups for said storms
early this afternoon. But we will need to keep an eye on IAH as
well over the next few hours. In addition, non- thunderstorm winds
will be gusty, at times over 25 knots. Locally stronger winds,
along with the risk of hail, is expected near the stronger
thunderstorms. This evening and tonight, a line of thunderstorms
is expected to push through the region. The timing of the line is
indicated in the TEMPO groups in the TAFs. Drier air tries to
filter into the region behind the front. But it may not be enough
to prevent lowered vis/cigs late tonight and tomorrow morning.
Vis/cig forecast confidence generally lower than normal tonight.

&&

.MARINE...
Issued at 1158 AM CST Mon Nov 24 2025

Caution flags may be needed at times today through Tuesday as winds
strengthen with a moderate to high risk of rip currents along Gulf-
facing beaches. Showers and storms are expected today leading up to
a cold front, which should more off the coast by Tuesday morning.
Moderate to strong northerly winds develop Wednesday morning as a
reinforcing front moves through the area, likely necessitating Small
Craft Advisories through Thursday morning. These stronger offshore
winds may bring negative water levels at low tide in the upper
portion of Galveston bay. Onshore flow returns by Friday,
increasing into the weekend as the gradient tightens ahead of the
next weather system.

03

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)  56  76  50  63 /  80   0   0   0
Houston (IAH)  65  80  55  68 /  80  10   0   0
Galveston (GLS)  72  79  61  70 /  60  40  10   0

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...Small Craft Should Exercise Caution until 6 PM CST this evening
     for GMZ330-335-350-355-370-375.

&&

$$

DISCUSSION...03
AVIATION...Self
MARINE...03