191
FXUS64 KHGX 131825
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
125 PM CDT Sun Jul 13 2025

...New KEY MESSAGES, DISCUSSION, MARINE...

.KEY MESSAGES...
Issued at 117 PM CDT Sun Jul 13 2025

- Showers and thunderstorms, a few capable of becoming strong to
severe, are expected this afternoon and evening. Potential hazards
include localized heavy downpours leading to minor flooding,
damaging winds and hail. The greatest risk of this activity is
anticipated to be north of I-10, especially across the Brazos Valley
and Piney Woods area through late evening.

- Hit-or-miss showers and thunderstorms are expected Monday and
Tuesday, especially in the afternoon along the sea breeze.

- A drier weather pattern is anticipated Wednesday and Thursday
accompanied by increasing temperatures and heat indices in the
triple digits.

- A coastal trough approaches the north-central Gulf coast towards
the end of the work week, bringing an increasing chance of
showers and storms across most of the region.

&&

.DISCUSSION...
Issued at 117 PM CDT Sun Jul 13 2025

We`re monitoring two key features influencing our weather conditions
today and Monday. A Mesoscale Convective Vortex(MCV) is moving
across central TX. Its eastward motion means we must closely
monitor it through the rest of the day for any generated outflow
boundaries that could push into our area, sparking rounds of
thunderstorms. We`re also watching an area of surface high
pressure situated along the southeastern coast and north-central
Gulf. While high pressure typically brings fair weather, in this
setup for TX, increased moisture along with daytime heating is
providing fuel for scattered thunderstorms this afternoon. This is
currently evident in our radar, where scattered activity
continues to develop and slowly move northward. As the afternoon
progresses, expect an increase in coverage, particularly in areas
north of I-10. With ample moisture, decent instability and a good
amount of dry air aloft, a few storms will be capable of becoming
strong to severe. Damaging winds and locally heavy rain will be
the primary hazards. Hail cannot be ruled out with any stronger
cells. Given the slow-moving nature of these storms, localized
heavy downpours are expected, which could lead to isolated/minor
flooding. Rainfall totals up to 1 inch are expected with pockets
of 2 to 3+ inches possible. These risks are highlighted in the SPC
and WPC day 1 severe weather and excessive rainfall outlooks.
Most of this activity will depend on the eastward motion of the
MCV. Therefore, rain and storm chances continue this
evening/tonight, especially across portions of the Brazos Valley
and Piney Woods areas.

The main longwave trough across the Southern Plains will continue
its northeastward motion, moving away from the region. However, some
lingering forcing along the southeastern edge will remain over the
region, enough to produce showers and storms on Monday. Afternoon
activity is once again expected, mainly along the sea breeze.
Tuesday keeps afternoon chances for rain and storms; however, with
the surface high centered more towards our region, these showers
will need to overcome stronger subsidence. Wednesday and Thursday
continue to be the driest days of the week thanks to the influence
of the ridge over the region. With a drier airmass, hot conditions
are also expected. Above normal temperatures will generally be
expected with highs in the mid to upper 90s.

As we head into the end of the long-term range, we`ll see an
increase in rain and storm chances. We`re closely monitoring a
possible area of low-pressure system likely to develop across the
northeastern Gulf in the next few days. Deterministic models
continue to show a westward movement of this system, potentially
reaching our region Friday into the weekend with increasing rain and
storm chances from the east.

JM

&&

.AVIATION...
(12Z TAF Issuance)
Issued at 619 AM CDT Sun Jul 13 2025

The primary feature of interest is a complex of tsra to the
northwest of our area. This activity is expected to push southeast
and bring scattered shra/tsra to portions of our area. There
remains uncertainty regarding tsra coverage. That being said, we
lean towards our northern terminals having the best just chance of
tsra (thus the TEMPO groups). Areas farther south continue to have
PROB30s due to the uncertainty. Whether or not we get tsra near
the coast is particularly uncertain. Most models show no tsra at
the coast later today. But moisture levels are high and could
allow for tsra development farther south. Any sub-VFR conditions
this morning should improve to VFR in the next few hours. However,
sub-VFR conditions will possible in any thunderstorm that occurs.

&&

.MARINE...
Issued at 117 PM CDT Sun Jul 13 2025

Rinse-and-repeat weather pattern with isolated showers early in the
morning and isolated to scattered thunderstorms after midday.
Surface high pressure system across the north-central Gulf maintains
the region under light to occasionally moderate onshore winds and
seas of around 3 to 4 ft, with occasional heights reaching around
5ft. A similar weather pattern is anticipated on Monday, with
slightly lower precipitation chances on Tuesday. Wednesday and
Thursday look generally dry, before the arrival of a coastal trough
from the east by Friday. This disturbance will be the next weather-
maker, bringing scattered convection across the upper TX coast into
the weekend. Gusty winds and elevated seas can be expected near any
thunderstorms.

Beach conditions: Be careful at the beach as there is still a
Moderate to High risk of rip currents along all Gulf-facing beaches
through this evening. Use extra caution! Always follow beach flag
systems, swim near a lifeguard and stay away from piers and jetties.

JM

&&

.TROPICAL...
Issued at 1218 AM CDT Sun Jul 13 2025

You might be surprised to see a Tropical section in the AFD, but
rest assured there is no need to worry. This is only being
addressed since there will probably be questions about the low
(20%) probability of tropical development in the central/eastern
Gulf over the next seven days. Going into early next week, a
trough of low pressure is expected to develop near or around the
Big Bend region of Florida (far eastern Gulf) and drift westward
towards the central Gulf staying right along the coast. Some
gradual development of this coastal trough is possible around or
after midweek. The vast majority of ensemble members take this
trough of low pressure into the north-central Gulf coast bringing
that region rounds of heavy rainfall. Towards the end of the work
week, some of that moisture drifts into the Upper Texas coast
bringing an increase in rain chances for our area. Other than
increased rain chances late in the work week, no other impacts are
expected for Southeast Texas at this time.

Stay up to date on the latest Tropical Weather Outlooks from the
National Hurricane Center at hurricanes.gov and stay up to date on
the latest forecasts for Southeast Texas at weather.gov/houston

Batiste

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)  90  74  91  75 /  70  20  30   0
Houston (IAH)  92  76  92  77 /  50  10  40   0
Galveston (GLS)  90  83  90  83 /  20  20  30  10

&&

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

$$

DISCUSSION...JM
AVIATION...Self
MARINE...JM