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National Weather Service Forecast Discussion

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780
FXUS64 KHGX 291027
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
527 AM CDT Wed Apr 29 2026

...New AVIATION...

.KEY MESSAGES...

- Scattered showers and thunderstorms (especially north of I-10)
  today and tomorrow. A few storms capable of hail and damaging
  wind gusts are possible. Localized flooding also possible.

- Strong late season cold front, and associated rain / storms,
  will push through the area Friday and Friday night followed by
  much cooler and breezy conditions in its wake.

- Strong winds (possible gales) expected over the Gulf and bays
  Friday night into Saturday.

&&

.DISCUSSION...
Issued at 1216 AM CDT Wed Apr 29 2026

The next 24 hours will be synoptically governed by a strong
mid/upper ridge over Mexico and a deepening mid/upper trough over
the Great Lakes region. The steepening mid/upper pressure heights
gradient will strengthen westerlies in the mid and upper levels
overhead, along with a general enhancement of the deep
subtropical jet that is prevalent from 700 MB up to at least 200
MB. These features aloft will enhance 0-6KM bulk shear (over 50
knots) across the region on Wednesday. Embedded in the flow will
be vort maxes / short waves, adding lift to our sheared
environment. Instability and moisture will not be in short supply.
Sfc based CAPE should remain high areawide, while PWATs are
expected to approach (maybe exceed) 2.0 inches for areas north of
I-10. Meanwhile, a frontal boundary should slowly sag southward
across the region, adding sfc convergence and additional lift to
the equation. We`ll also have to monitor any residual boundaries
from the outflow of Tuesday night`s storms.

The aforementioned ingredients should prime the SE Texas
atmosphere for thunderstorms on Wednesday, w/ the highest chance
of showers/storms being north of I-10. That doesn`t mean we can`t
see thunderstorms south of I-10. But the preponderance of data
suggests the highest PoPs will be north of the corridor. Strong
bulk shear and some veering in the LL wind profile could allow
deep convective to take on a discrete mode, which would increase
the risk of thunderstorms capable of large hail and damaging
winds. If any cells manage to train, then localized flash flooding
would become a concern. Temperature wise we are looking pretty
warm with high humidity. Areas that remain south of the boundary
could hit the low 90s with enough sunshine. Certainly a summery
feel to the day for many.

The synoptic forces begin to change as we head into Thursday and
Friday. A robust mid/upper low is expected to push into SW CONUS
on Thursday. The overall set up on Thursday might not be THAT
different than Wednesday. The boundary that pushes south on
Wednesday may stall or even drift northward on Thursday. Where
that boundary sets up could be the primary focal of where
Thursday`s deep convection occurs. But as we head into Friday, the
aforementioned mid/upper low ejects eastward, amplifying the
subtropical jet over Texas. In addition, the flow aloft becomes
increasingly diffluent, supporting significant large-scale lift.
At the surface, our boundary begins to sag south as a 1025MB sfc
high builds into Texas from the north. Though thunderstorms along
and south of the boundary are a concern, the best chance of
heavier rain may actually be north of the boundary where moist,
tropical air overruns the much cooler air below. CAA will likely
induced a strong LL temperature gradient between the tropical air
over the Gulf and the colder continental air surging southward.
The gradient coupled with the lift could enhance LL pressure falls
near the front, steepening the LL gradient and enhancing
northerly winds. These winds may become especially strong near the
coast and offshore late Friday and into Saturday. Chance of gales
is increasing over the bays and Gulf. Friday`s temperatures
forecast is very tricky. I`m not going to be surprised if areas
behind the front drop into the 50s during the afternoon while
areas ahead of the front manage to hit 80. Timing of the front
will be key when it comes to afternoon temps.

The system exits the picture by Saturday, yielding to a very nice
weekend. Temperatures will be well below average. Saturday
afternoon temperatures are expected to be in the upper 60s to low
70s. Sunday a tad warming in the mid to upper 70s. Overnight lows
are expected to fall into the 40s in our northern zones. Brrrrr!
Most elsewhere should drop into the 50s (60s at the beaches). The
cool will not last. Expect a warming trend next week along with
increasing humidity. We are approaching summer after all.

Self

&&

.AVIATION...
(12Z TAF Issuance)
Issued at 527 AM CDT Wed Apr 29 2026

Widespread MVFR ceilings will continue through the morning before
lifting back to VFR in the late morning to early afternoon hours.
Scattered showers and thunderstorms are expected to develop in
the late morning/early afternoon beginning near the northern
terminals and drifting southward through the afternoon. Timing of
the convection and how far south the storms last are a bit
uncertain as each high-res model guidance member offers a
different solution. The PROB30`s are a current best guess, but may
be amended based on radar trends later today. These showers/storms
will be developing along a frontal boundary, so expect winds to
remain generally below 10 kt throughout the day. Light northerly
winds will prevail behind the front (most likely CXO northward)
and light southerly winds will prevail south of the front.
Widespread MVFR/IFR ceilings expected overnight along with
scattered rain showers and isolated thunderstorms overnight into
Thursday morning...although the timing and location of these
are also uncertain.

Batiste

&&

.MARINE...
Issued at 1216 AM CDT Wed Apr 29 2026

Generally moderate southeasterly flow and occasionally enhanced
swell is expected through Friday. Couldn`t rule out a shower or
thunderstorm on Wednesday and Thursday. But the primary
shower/thunderstorm threat is expected to remain well to the
north. There is a much higher chance of rain and thunderstorms on
Friday into Saturday morning due to the passage of a strong cold
front. Southeast winds may increase somewhat on Friday as the
front nears. Very strong northerly winds and building seas are
expected behind the front Friday night into Saturday. High-end
Small Craft Advisory conditions should easily be accomplished,
with an increasing risk of gales for the bays and Gulf. Offshore
seas may top 10 feet by Saturday morning. Winds and seas should
gradually improve Saturday afternoon into Sunday, with a light to
moderate onshore flow regime returning by Monday.

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)  83  67  79  61 /  70  40  40  70
Houston (IAH)  90  72  85  66 /  40  30  40  50
Galveston (GLS)  83  75  81  73 /  20  10  20  30

&&

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

$$

DISCUSSION...Self
AVIATION...Batiste
MARINE...Self

NWS HGX Office Area Forecast Discussion