949
FXUS64 KHGX 030457
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1157 PM CDT Fri Oct 2 2026

...New DISCUSSION, AVIATION, MARINE...

.KEY MESSAGES...

- Periods of showers and thunderstorms are expected through
  Sunday. Locally heavy rain will be possible and could lead to
  instances of flash flooding. Best chances for heavy rain is
  along the coast.

- Cold front pushes through early next week bringing drier air and
  slightly cooler temperatures.

&&

.DISCUSSION...
Issued at 1157 PM CDT Fri Oct 2 2026

Scattered showers/storms have mostly waned for the evening, but
some of the latest high-res model guidance keeps some isolated
activity going through the early half of the night as a weak
nocturnal LLJ develops on the northern side of an approaching
coastal trough. PW values remain near or above the MAX percentile
(~2.3") alongside plenty of instability, so any little source of
lift is enough to squeeze out some rainfall...and more of that is
to come over the weekend. Synoptically, an upper level cutoff low
remains over western TX with an associated surface frontal
boundary draped somewhere in southeast TX. Finding the front is
essentially on expert mode as it is VERY diffuse and washed out.
Going into Saturday, a coastal low/trough in the western Gulf will
gradually lifting northward towards the northwestern Gulf coast.
Areas generally south of I-10 will be in the middle of the
moisture axis from the upper cutoff low (and associated frontal
boundary) and the coastal trough/low. So, our attention remains on
our coastal areas over the weekend as this two features interact.

The aforementioned frontal boundary is expected to be just offshore
on Saturday, but as we talked about before it`s hard to tell exactly
where it`ll be as the winds become easterly from south to north with
the approach of the coastal trough/low. PW values remain near the
MAX percentile, so a nearby frontal boundary, a coastal trough/low,
moisture convergence between the two, and embedded shortwaves in
flow aloft will keep the potential for locally heavy rainfall over
the weekend...most specifically late Saturday into Sunday mainly
along the coast. There two sources of moisture coming together will
essentially act as a sponge wringing itself out. The latest suite of
model guidance indicates that the highest rainfall totals will occur
just off of the coast. Rainfall totals right along the coast are
generally anticipated to be in the 1-3" range Saturday through early
next week. Areas further inland will likely remain under an inch,
but there will be potential for isolated higher amounts both along
the coast and further inland...much less likely further inland.
Daytime heating, positioning of shortwaves, and a ~25 kt LLJ could
lead to a couple of heavier downpours north of I-10 on Saturday
afternoon, but most of the heavy rainfall potential lies along the
coast.

Keep in mind that the highest rainfall totals are anticipated to
occur just 10-20 miles off the coast. That`s a relatively small
margin of error...a small nudge northward and we could see these
higher totals occur further inland. It`s worth noting that there`s
still some deterministic guidance that forms a surface coastal low
while others keep an open trough...it remains to be seen which of
these scenarios will play out. The previous forecaster also made a
great point that water levels will be higher than normal, so heavy
downpours during high tide (late evening to overnight hours) would
increase the potential for flooding due to the slower drainage.
We`ll have fairly similar conditions on Sunday, but it will be
slightly dependent on if a coastal low manages to develop. If it
does, then it may manage to keep most of the rainfall offshore
whereas an open trough keeps the door...well open for rainfall to
push further inland. Resultingly, WPC has maintained a marginal risk
(level 1 of 4) of excessive rainfall for Saturday and Sunday for all
of Southeast TX with the main flooding risk being right along the
coast.

Coastal rain chances continue on Monday, but Monday will be a bit of
a transition day to drier horizons. A cold front is anticipated to
push through Monday night/Tuesday morning as an upper level trough
dips down into the northeastern/eastern CONUS. We`ll get the tail-
end of this front, so it won`t be a substantial cooldown by any
means...but it will be a noticeable one. Low temperatures for most
of the work week beyond Monday are expected to range from the low
60s to the low 70s. For those that have been reading the AFDs over
the past few nights, I`ve been throwing probabilities for low
temperatures below 70 degrees for the city of Houston. Last night,
these probabilities were peaking around 60%. The latest
probabilities peak around 70-75% now...those are pretty good odds!
High temperatures are expected to be in the 80s through the next
work week due to increased rain chances over the weekend followed by
the early week cold front.

Drier air behind this front means that we take a break from the rain
chances for most of the work week. We`re going from PW values above
the MAX percentile to closer to the 25th percentile (~1.06") with
dew points possibly as low as the upper 40s/low 50s. It`s a bit
uncertain on exactly when moisture begins to return, but it does
appear to be towards the end of the work week. I`m on the border of
entering fantasy land, but the tail-end of the work week does look a
bit interesting. There is some general agreement in deterministic
guidance on an upper low cutting off from a longwave trough near TX
towards the end of the work week as another coastal trough/low
drifts northward from the Bay of Campeche. What happens beyond that
is anyone`s guess at this point, but at the very least it looks like
rain chances return going into next weekend.

Batiste

&&

.AVIATION...
(06Z TAF Issuance)
Issued at 1157 PM CDT Fri Oct 2 2026

Widespread MVFR cigs expected by morning. Outside of CLL and UTS,
VFR conditions will return for all TAF sites by 18Z. A southward
moving cold front will lead to persisting MVFR cigs at CLL and
UTS, with a drop to IFR cigs likely through the afternoon. This
cold front could also result in isolated to scattered showers and
thunderstorms for all TAF sites along and north of I-10. A PROB30
was written to highlight the greatest rain chance for these TAF
sites between 20 and 00Z. Showers and thunderstorms that develop
over these terminals carry the potential to bring sub-VFR cigs/vis
and gusty winds. Additionally, a westward moving trough in the
Gulf will create persistent showers and thunderstorms near the
coast, warranting prevailing -SHRAs and PROB30 -TSRAs for LBX and
GLS. Winds through this TAF cycle will primarily be NE at 10-12
kts.

&&

.MARINE...
Issued at 1157 PM CDT Fri Oct 2 2026

Easterly to northeasterly winds will gradually increase overnight
leading to gradually building seas. Caution flags are in effect for
the Gulf waters through early Sunday morning then will need to be
transitioned to a Small Craft Advisory as winds and seas increase
further. In addition to that, water levels will continue to peak
around or just above 3.0 ft MLLW during high tide through the
weekend, so not enough for coastal flooding hazards but high enough
for mariners to take note. Chances for showers/storms persists
through the weekend and into midweek as a coastal weather system and
frontal boundary interact.

Another cold front will push offshore early next week bringing
moderate to strong northeasterly winds peaking around 25 kt
sustained and 6-8 ft seas periodically throughout the week. As
previously mentioned, shower/storm chances linger over the Gulf
waters into midweek.

Batiste

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)  72  84  70  83 /  20  50  20  20
Houston (IAH)  75  88  74  84 /  30  40  40  30
Galveston (GLS)  80  87  78  85 /  40  70  70  60

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...Small Craft Should Exercise Caution from 4 AM CDT Saturday
     through late Saturday night for GMZ350-355-370-375.

&&

$$

DISCUSSION...Batiste
AVIATION...JMG
MARINE...Batiste