Area Forecast Discussion
Issued by NWS Houston/Galveston, TX

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591
FXUS64 KHGX 180006
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
706 PM CDT Fri Oct 17 2025

...New AVIATION...

.KEY MESSAGES...

- Moderate fire danger remains for majority of Southeast Texas and
  on Friday due to dry vegetation/fuels.

- Unseasonably warm weather continues as high temperatures in the
  mid 80s to lower 90s persist into early next week. Heat index
  values on Saturday will peak in the upper 90s.

- Chances for isolated to scattered showers and storms continue
  through late Saturday/early Sunday ahead of an approaching weak
  cold front.

- Drier air and breezy northeasterly winds behind the front
  leading to moderate to high fire danger rating for Sunday.

&&

.DISCUSSION...
Issued at 1139 PM CDT Thu Oct 16 2025

After the summer we had where it seemingly rained everyday, I didn`t
imagine that we`d be begging for rain a couple of months later. That
led me to do some investigating to see exactly how long it`s been
dry. The last day of measurable rainfall for the City of Houston was
on September 24th. If you`re reading this on October 16th, that was
22 days ago. Most of y`all are reading this on October 17th, so that
was 23 days ago. Three solid weeks of NO measurable rainfall...yeah
we need some rain y`all. Thanks to the return of onshore flow
bringing in a plume of Gulf moisture (PW values peaking in the 1.6-
1.9" range) and lingering PVA from an embedded shortwave, we will
see scattered showers and storms pushing through the area beginning
Friday morning and lasting into the afternoon. The highest rain
chances will be mainly along and west of I-45. Rainfall totals could
pile up a tad bit where showers/storms initially push in in a broken
south to north oriented line. This would likely result in 1-2" of
rainfall and this looks to be most likely to occur near Matagorda
Bay. Thanks to the increased chances of rain, high temperatures will
top out in the mid to upper 80s, which if you`re keeping track is
still above normal. If you recall from yesterday`s AFD, we discussed
that the City of Houston has not had a below normal maximum
temperature since September 9th. While there is a "cold" front to
talk about, don`t expect that streak to end any time soon.

These rain chances stick around going into Saturday as an upper
level trough and an associated weak cold front begin to push through
Texas. The approaching front will nudge the bulk of the moisture
eastward leading to the highest rain chances on Saturday being along
and east of I-45. Friday`s rain chances are mainly west of I-45, and
Saturday`s rain chances are mainly east of I-45...perfectly balanced
as all things should be. One difference for Saturday is that we add
in quite a bit more instability and a little bit of shear. The shear
will be higher further to the north and east, but a combination of
those ingredients does offer the potential for some storms to become
strong to severe on Saturday in the Piney Woods area. SPC (as of the
2pm CDT Thursday update) has outlined areas generally east of a
Madisonville-Huntsville-Shepherd line in a marginal risk of severe
weather (level 1 out of 5). The main hazard will be damaging winds,
but we can`t entirely rule out hail or a brief isolated tornado.
We`ll also get some warmer 850mb temperatures (90th+ percentile)
nudged in our direction on Saturday as well. That`ll lead to
temperatures topping out mainly in the low 90s, but it`ll feel
hotter than that when you factor in the elevated humidity. Heat
index values will peak in the mid to upper 90s, so Hot-ober
continues!

On Wednesday evening, the 18Z GFS pump faked us with a run that said
the front wasn`t going to push through and now it`s back. So,
tonight`s deterministic model guidance is in consensus on the
frontal boundary pushing through on Sunday morning. There looks to
be a broken band of showers/storms associated with the front as it
pushes through, but it looks like it`ll push out ahead of the front
and move in on late Saturday with most of the convective coverage
remaining east of I-45. Drier air filters in on Sunday
morning/afternoon, but it`ll be brief. While it`ll still be in the
upper 80s to low 90s in the daytime, it`ll be a dry heat compared to
Saturday. Model guidance is a bit uncertain on how quickly onshore
flow returns, but it will occur by Monday. If it occurs closer to
Sunday night/Monday morning, then that`ll have an impact on the low
temperatures. As of right now, we have low temperatures ranging from
the low 50s to low 60s (low 70s along the coast). As onshore flow
returns early next week, mid to upper level high pressure expands
over northern Mexico towards the western Gulf coast. Another trough
sweeping through the Central Plains midweek may allow another front
to approach the area, but I`m not entirely convinced on that one
since the associated trough and upper level low pushes through the
Northern Plains into the Great Lakes region. That would leave us
under control of the ridge albeit with the main ridge axis to our
west.

If you hate math (specifically statistics), you should probably go
ahead and stop reading right here. To get an indication of the
uncertainty of next week`s front, let`s take a look at some box and
whisker plots! Going into midweek, there is a notable increase in
the low temperature spread. That comes to tune of a 10+F difference
between the upper quartile and the lower quartile. There are a few
ensemble members that bring upper 50s/low 60s to the metro area
around midweek, but there are quite a few more that keep us in the
upper 60s/low 70s. The latest run of the NBM is now leaning towards
the FROPA-less solution as it keeps low temperatures next week
generally in the 60s...and we`ll see if that upward trend continues.
See, math DOES have real world application! *insert nerd emoji here*

Batiste

&&

.AVIATION...
(00Z TAF Issuance)
Issued at 634 PM CDT Fri Oct 17 2025

VFR conditions will continue through this evening, but moist
onshore flow will bring a period of MVFR CIGs to the area late
tonight into the mid-morning hours on Saturday with ceilings
around 1500-2500ft. Wind speeds during the overnight hours will
generally be between 4-8kt, and then increase to 7-12kt by the
mid-morning hours on Saturday and persist through the evening. The
increase in moisture will also lead to scattered showers and
eventually thunderstorms during the day tomorrow. Isolated shower
activity will begin near the coast near dawn, then spreading in
coverage through most of the area by the afternoon hours.
Scattered, pop-up thunderstorms will develop by the late morning
to afternoon hours with the greatest chances being CXO southwards.
There will be a lull in the activity during the evening to early
overnight hours, but a weak boundary approaching from the
northwest will bring additional rain chances late Saturday night
into Sunday morning. This is beyond the end of this TAF package,
but expected a broken line of showers and storms to move through
after 6z with a period of northwesterly winds developing behind
it.

Fowler

&&

.MARINE...
Issued at 1139 PM CDT Thu Oct 16 2025

Onshore flow persists leading to the gradual increase of moisture
heading into the weekend. Expect chances for showers and storms to
gradually increase going into Friday and Saturday. Wind speeds may
approach the caution flag threshold on Friday night into Saturday
morning to go along with seas elevating to around 4 ft. This
increased onshore flow will lead to an increased risk in rip
currents late Friday into the weekend. Chances for isolated to
scattered showers and storms will persist until a frontal boundary
pushes through on Sunday. Expecting a brief period of northerly to
northeasterly winds behind the front on Sunday, but southeasterly
winds make a quick return by Monday.

Batiste

&&

.FIRE WEATHER...
Issued at 1139 PM CDT Thu Oct 16 2025

Although moisture is on the rise, dry vegetation/fuels remain
especially in portions of the Brazos Valley and the Piney Woods. As
a result, the fire danger rating for Friday is still moderate for
most of Southeast Texas. The increased moisture means an increase in
rain chances, especially for Friday and Saturday ahead of a weak
cold front that looks to push through on Sunday.

On Sunday, we could see an overlap of drier air (minimum RH values
25-35%) and breezy northeasterly winds, which would create
another day of elevated fire weather conditions. We are currently
looking at a moderate to high fire danger rating for Sunday with
those outlined in a high fire danger rating generally north of
I-10.

Lastly, the vast majority of the counties in Southeast Texas now
have a burn ban in place. The only counties that do not have a burn
ban as of Thursday night are Brazoria and Galveston Counties.

Batiste

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)  70  91  65  83 /   0  30  30   0
Houston (IAH)  72  89  70  84 /   0  50  30  10
Galveston (GLS)  78  85  74  84 /  10  20  20  10

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&

$$

DISCUSSION...Batiste
AVIATION...Fowler
MARINE...Batiste