850
FXUS64 KHGX 300528
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1228 AM CDT Sat Aug 30 2025

...New DISCUSSION, MARINE...

.KEY MESSAGES...
Issued at 1227 AM CDT Sat Aug 30 2025

- WPC has a Marginal Risk of Excessive Rainfall across Southeast
  TX with a Slight Risk across East TX. A Marginal Risk continues
  through Monday.

- Labor Day should generally be cooler with rain chances
  continuing, particularly closer to the coast. Rain chances
  decrease next week as drier air filters into the region.

- High temperatures should remain relatively near seasonal
  averages; a bit cooler where it rains, a bit warmer where it
  does not. At night, lows should gradually slide through the 70s
  towards the upper 60s inland as the drier air filters in.

&&

.DISCUSSION...
Issued at 1227 AM CDT Sat Aug 30 2025

Friday was a more convectively active day across Southeast Texas
than Thursday, but I do have to admit it wasn`t *quite* as busy as
I thought it might be. The diffuse front has now stalled across
the area, and while it`s not really coherent enough to clearly
delineate, it`s probably fair to say it`s roughly in the area of
I-10, perhaps a little north of it. It`s also not likely really
that important to precisely draw the line, anyway. It will help to
provide a focus for convergence for new development of showers and
storms this weekend - primarily, but not entirely in the
afternoons.

Moisture is pretty plentiful, with precipitable water values above
2 inches and should remain there, around/above the 90th
percentile through Sunday night. With such ample moisture, it`s
likely not surprising that heavy rain potential is on my mind.
Fortunately, flow aloft is a bit better than the light and
variable boundary layer flow, which should help storms keep some
movement - not a ton, but enough to help mitigate concern from
strong storms dropping extended amounts of heavy rain.
Additionally, the scattered to numerous storm development should
be a bit more haphazard, and less prone to training. Still,
summertime temperatures should provide some solid instability and
give the strongest storms of the day the opportunity to drop
multiple inches of rain quickly before the cell rains out. And,
should that be over a poor drainage spot, localized flooding
concerns could emerge - you know, the usual for this time of year
around here. Unsurprisingly, there is a marginal risk (threat
level 1 of 4) for excessive rain through the weekend, and even
lingering into Monday closer to the coast to account for this
scenario.

Outside of that though, it should be a pretty summerlike "last
weekend" of summer this holiday. Temperatures near or a little
above average from around 90 into the middle 90s and the
aforementioned scattered to numerous showers and storms. You`ll
definitely want to be ready to react for when it`s your turn to
see a storm this weekend, but we are also not looking for any sort
of washout or large swaths of rain to dominate any day of the
holiday weekend.

Beginning Monday, but taking hold deeper into the new week, will
be a bit of drier air filtering in behind this front as it slowly
slides offshore. This should be aided by a weak reinforcing front
arriving later on Tuesday and then yet another front towards the
end of the week. We`ll watch rain chances get shoved coastward and
dwindle, eventually being contained almost entirely over the Gulf
waters. I`m sure we won`t stay entirely dry, with afternoons
perhaps managing a few isolated cells off the seabreeze, but by
and large rain will not be see by most as the week goes on.

Though the first couple of fronts will bring drier air, it
probably isn`t going to do so much in the way of bringing colder
air, so it remains awkward in calling these boundaries cold
fronts. But, the drier air should help the oppressiveness of our
usual humidity, and at least at night should help let temperatures
fall more into the upper 60s and lower 70s, which is a thing we
haven`t really seen in quite a while. Towards mid-week, we should
see afternoon highs dip slightly below average, but it`s really
the humidity that will help the days feel any better.

The late week front, however, still mildly intrigues me. Both the
GEFS and Euro Ensemble suggest an unseasonably strong upper
trough that would help support this late week front. Now, don`t
get too excited. The anomalous upper winds and 850 temps (EPS
only) both are showing don`t dig all the way down to Southeast
Texas, so we`re certainly not going to be welcoming in fall with
this setup. Indeed, the GEFS 850 temps don`t dip below the 10th
percentile at all. But...I`m hopeful that the kind of trough we`re
looking for here will at least give us a taste of highs more in
the 80s than the 90s. Not so much heralding the beginning of fall,
but perhaps a hint that summer is heading towards its end.

That hope, the NBM says, is just a hope. It keeps upper 80s/lower
90s highs clear through to Saturday. But I do see that in the LREF
clustering analysis, the top two clusters, accounting for 61
percent of the LREF members are stronger than the grand ensemble
mean with this trough, and cooler with their 2m temps. And...the
LREF mean is already cooler than the NBM deterministic. So, while
I keep what`s explicitly in the forecast grids functionally the
same as the NBM, I suspect that any error in this forecast would
be on the cooler side of the bar than the warmer. But we`ve got
all week to see how things evolve.

&&

.AVIATION...
(00Z TAF Issuance)
Issued at 628 PM CDT Fri Aug 29 2025

The current isolated shra/tsra over the region should diminish
this evening. However, we cannot rule out some shra activity
overnight into the morning, especially over our northern counties
and near the coast. Guidance continues to suggest areas of MVFR
and some potential for areas of IFR during the morning hours which
is reflected in some of the TAFs. Though our northern areas have
the best chance of sub-VFR conditions, we cannot rule out MVFR
vis/cigs at IAH during the morning hours. For Saturday, the
primary concern will be shra/tsra associated with a frontal
boundary approaching from the north. Though there is technically a
chance of shra/tsra throughout the day, the best chance of this
occurring appears to be during the afternoon hours after 20Z.
Winds will generally be light and variable. But locally higher
winds are possible in the vicinity of any tsra.

&&

.MARINE...
Issued at 1227 AM CDT Sat Aug 30 2025

A late summer front stalls over Southeast Texas this weekend,
enhancing shower and thunderstorm activity through the holiday.
Winds over the weekend are expected to generally be light and
variable. However, locally stronger winds in the vicinity of
thunderstorms are likely. Winds are expected to turn back to being
broadly onshore later next week as the front drifts south and
dissipates. While rain chances should dwindle inland, daily isolated
to scattered showers and storms may persist over the Gulf.
&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)  94  76  92  76 / 100  20  40  50
Houston (IAH)  95  78  92  77 /  40  30  70  40
Galveston (GLS)  92  82  87  81 /  20  30  40  50

&&

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

$$

DISCUSSION...Luchs
AVIATION...Self
MARINE...Luchs