Houston, Texas 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

681
FXUS64 KHGX 291118
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
618 AM CDT Sun Jun 29 2025

...New AVIATION...

.KEY MESSAGES...
Issued at 143 PM CDT Sat Jun 28 2025

- Shower/thunderstorm chances remain higher for Sunday than previous
  days, though confidence in the rainfall coverage is lower than
  normal.

- Daily chance of showers/thunderstorms continue through the
  forecast period.

- Temperatures expected to become hotter beyond Monday.

&&

.DISCUSSION...
Issued at 1200 AM CDT Sun Jun 29 2025

Usually I like to begin my discussion with the current state of the
atmosphere. But today, I want to uncharacteristically start with the
models. When glancing at all available short-term, hi-res, global,
and ensemble data, one will notice quite the variance regarding the
coverage of shower and thunderstorm activity for both today and
tomorrow. Let`s start with today`s atmosphere. A plume of higher
PWAT is approaching from the Gulf, thanks in part to Tropical
Depression Two in the Bay of Campeche. This surge of tropical
moisture is expected to bring widespread 2.0+ inch PWAT values to
our region today, with these high values reaching our coastal
counties during the early morning hours while areas farther inland
reach these PWAT numbers by afternoon. Considering moisture levels
will be higher today than previous days, we still think that general
rainfall chances are higher than recent days. In addition, these
high PWAT values may support locally heavy rainfall, especially in
locations where deeper convection is favored. But there are factors
that could limit today`s convection to a shallower and less
widespread variety. For starters, there`s the much talked about
plume of mid-level Saharan Dust. However, various satellite Saharan
Air Layer analyses indicate that the dust levels aren`t as high as
the often shared NASA Dust Extinction Aerosol Optical Thickness
model suggests. In addition, the bulk of the dry mid-level air may
not reach our area until Monday. So wouldn`t that suggest the high
PWATs will win out? Well....there`s one other factor, vorticity.

The National Hurricane Center`s forecast has Tropical Depression Two
becoming a minimal Tropical Storm before moving ashore into Mexico
this evening. As the system gets a little better organized, the
overall vorticity field may contract somewhat. There`s a plethora of
guidance suggesting a scenario like this, where a stream of enhanced
vorticity becomes a potential focus for deeper convection offshore
to our south. This scenario doesn`t completely rid our region of
showers and storms. But the deeper convection to the south /
offshore hogs some of the inflow and moisture, limiting the coverage
and the depth of convection across our neck of the woods.
Considering this forecast has managed to become more uncertain than
I thought it was yesterday, I`ve decided to go along with the lower
PoPs the NBM is selling. HOWEVER, PoPs across much of the region
remain 50-70%, which is higher than recent days. The exception is
across our Brazos Valley counties where PoPs are 20-40%. In the case
of Monday, the battle will be between the LL tropical moisture and
the increasing influence of the Saharan Air aloft. Monday`s PoPs
range from 20-30% across our northern counties to 30-50% in our
southern zones.

For the remainder of the week, increased ridging and lingering mid-
level dust results in a lower PoP regime with higher temperatures.
Inland highs are expected to average in the mid 90s. But we are not
expecting the atmosphere to be suppressive enough to eliminate the
chance of diurnal showers/thunderstorms. Therefore, the daily risk
of showers/storms remains in the forecast through the end of the
week.

Self

&&

.AVIATION...
(12Z TAF Issuance)
Issued at 615 AM CDT Sun Jun 29 2025

Combination of some low level speed convergence near the coast
and increased surge of Gulf moisture is leading to scattered
showers along the coast and offshore. This activity will
transition inland later this morning and afternoon compliments of
daytime heating. Precip coverage should generally be highest
across southern parts of the region (CXO southward), but terminals
further north are fair game late in the day. Doesn`t look like a
situation where we`ll see widespread coverage, but persistent
scattered activity that`s hard to pinpoint timing at any
individual location. After some intermittent MVFR cigs in the mid
morning hours, VFR conditions should mostly persist (with the
exception of in/near an isolated stronger cells). With the loss of
heating, rain should taper off in the early-mid evening hours. 47


&&

.MARINE...
Issued at 1200 AM CDT Sun Jun 29 2025

The National Hurricane Center is issuing advisories for Tropical
Depression Two in the Bay of Campeche. The system is forecast to
become a minimal tropical storm by the time it reaches the coast of
Mexico near in the vicinity of Tampico. Despite this track well to
the south of our region, moisture from the system is expected to
bring scattered showers and thunderstorms to the area today. In
addition, southeasterly swell is expected to increase somewhat later
today, possibly reaching 5-6 feet in our marine zones farther
offshore. For the rest of the week, we are expecting continued daily
chances of isolated to scattered showers/thunderstorms, along with
light to moderate onshore winds and 2-4 foot seas.

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)  92  75  94  74 /  40  10  20  10
Houston (IAH)  90  77  93  76 /  60  20  40  10
Galveston (GLS)  89  82  89  81 /  50  20  30  10

&&

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

$$

DISCUSSION...Self
AVIATION...47
MARINE...Self