Skip to main content.

National Weather Service Forecast Discussion

Related quick links> 5 Day Forecast, Local Advisories, Drought Monitor, UV Forecast, Air Quality Forecast 
792
FXUS64 KHGX 291659
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1159 AM CDT Wed Jul 29 2026

...New DISCUSSION, MARINE...

.KEY MESSAGES...

- Generally hot and dry through the end of the week, with heat
  index values close to Heat Advisory thresholds.

- Isolated showers are possible along the sea breeze boundary
  today and tomorrow.

- Scattered showers and thunderstorms return to the forecast this
  weekend and early next week.

&&

.DISCUSSION...
Issued at 1200 PM CDT Wed Jul 29 2026

Our main concern today will be heat and humidity resulting in heat
index values that are very close to our Heat Advisory threshold.
We have decided to not issue an advisory today with the latest
forecast update, and here is some of our reasoning. It looks like
temperatures will climb into the upper 90s once again today--very
similar to yesterday. Also similar to yesterday, the boundary
layer should deepen and sufficiently mix surface dew points into
the low 70s, perhaps the upper 60s for a few locations across the
west/northwest portions of our forecast area. This will result in
heat index values between 105-107 for most locations, with a few
spots meeting criteria (108-109) for an hour or two. The locations
that are forecast to meet criteria are isolated and generally more
sheltered. Due to the splotchiness of locations just reaching
criteria, we did not feel it necessary to issue an advisory in
this situation. We will continue to assess current data and
adjust as necessary.

It`s worth noting that we`re still forecasting heat index values
between 105-108. At the end of the day, the human body and an
animal`s response to heat does not vary much between 107 and
108...therefore proper heat safety messaging and precautions
should continue to be taken regardless of the presence of an
advisory or not.

Aside from the heat, we have 10-20% PoPs over eastern Harris
county this afternoon and areas extending north of the Houston
Metro near sunset. It looks like a seabreeze circulation will
develop off the Gulf and Galveston Bay that should provide enough
low-level convergence to trigger an isolated shower or two this
afternoon from about 4-8 pm. Forecast soundings indicate a
sufficiently moist/unstable boundary layer to support shallow
showers, but individual updrafts should not be strong enough to
overcome a capping inversion around 700mb/10kft, as well as the
strong subsidence and dry-air entrainment aloft. Therefore, we
only mention a slight-chance of showers in the official forecast
and capped thunderstorm chances at less than 15%. A similar setup
is forecast tomorrow, so we have similar PoP/precip trends for
tomorrow afternoon as well.

Thursday and Friday`s weather will be quite similar to today (and
yesterday and the day before that) with temperatures in the upper
90s and heat index values between 105-108 for most locations. The
stagnant weather pattern should start to break down as we head
into the weekend. The surface high to our southeast and intense
mid- and upper-level ridge/high to our northwest will give way to
a trough over the eastern CONUS early next week. As this ridge
breaks down, a backdoor cold front is forecast to slide into
Southeast Texas this weekend. We use the world cold very loosely,
since there won`t be much a cool-down (we go from the upper 90s to
the mid 90s) with it. It should at least bring increased rain
chances to the region. Unfortunately rain chances are only around
20-30% for most of the area, with 50+% PoPs further east toward
the Golden Triangle. There is a chance that the upper trough digs
more south than southeast, which would nudge those 50+% PoPs west
into our forecast area, but only about 25% of the global guidance
is favoring this solution at this time. The global guidance is in
agreement that the front will not be here for a long time and wash
out/lift north as we head into early next week with a more staunch
fetch of southerly flow blowing across the region. This pattern
usually results in temperatures in the mid/upper 90s with daily
diurnal seabreeze induced shower/storm chances.

Bonnette

&&

.AVIATION...
(12Z TAF Issuance)
Issued at 619 AM CDT Wed Jul 29 2026

A forecast of persistence looks tough to beat. A few isolated
patches of higher end MVFR cigs/fog north and west of the metro
area will burn off early this morning, with VFR conditions
anticipated area-wide for the rest of the day. Will keep an eye
on the possibility of a late day seabreeze/baybreeze shower or
tstm around the metro (similar to yesterday), but will not include
the mention in the 12z TAFs.  47

&&

.MARINE...
Issued at 1200 PM CDT Wed Jul 29 2026

Light to moderate onshore flow and 2 to 4 foot seas will continue
for most of the week. Winds may become more southerly during the
afternoon and hours. Southwesterly winds increase and seas build
somewhat over the weekend, which may prompt the issuance of
caution flags. We also expect an increase chance of isolated to
scattered showers and thunderstorms by the weekend and early next
week.

Bonnette

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)  76  98  75  98 /   0   0   0   0
Houston (IAH)  78  99  78  99 /  20  20  10   0
Galveston (GLS)  82  92  82  91 /   0   0   0   0

&&

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

$$

DISCUSSION...Bonnette
AVIATION...03
MARINE...Bonnette

NWS HGX Office Area Forecast Discussion