Skip to main content.

National Weather Service Forecast Discussion

Related quick links> 5 Day Forecast, Local Advisories, Drought Monitor, UV Forecast, Air Quality Forecast 
540
FXUS64 KHGX 210506
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1206 AM CDT Sun Jun 21 2026

...New DISCUSSION, MARINE...

.KEY MESSAGES...

- Scattered to numerous showers and thunderstorms are expected
  through early today, with the potential for locally heavy
  rainfall mainly between the I-10 corridor and the coast.

- Heat will remain a concern through midweek, with heat indices
  nearing 107F (41-42C) and overnight lows only falling into the
  upper 70s to lower 80s (26-28C).

- A high risk of strong rip currents will continue through the
  next few days.

&&

.DISCUSSION...
Issued at 1206 AM CDT Sun Jun 21 2026

Scattered clusters of showers and thunderstorms extend across our
offshore waters and closer to the South TX coast early this
morning, feeding off increased southerly flow from the nocturnal
low level jet. The environment was substantially worked over
across much of our land area yesterday afternoon, but the marine
areas were less impacted. As we head through the early part of
today, the more unstable airmass will begin to advect back
onshore and toward the I-10 corridor. With this, convection
currently ongoing over the Gulf will spread along the coast and
perhaps a tier or two of counties inland. Given the moist airmass
nearby and potential for training storms, WPC has posted another
slight ERO highlighting the more coastal areas. High res guidance
shows potential for locally higher amounts as we`ve seen in
recent days, which could result in flash flooding. Rain chances
will generally be lower further inland, where there`s less
confidence in the atmosphere recovering enough to support
convection.

Once again, clouds and rain will play a big role in today`s
temperature and heat index forecast with high res guidance showing
strong potential for rain and cloud debris to disrupt insolation,
particularly early in the day. Clearing, which will become more
likely this afternoon will provide some potential for better
warming. However, confidence in heat indices reaching advisory
criteria remains low for now.

A mid level ridge will begin to strengthen over the Texas coast
heading into the new work week, which will begin to put a cap on
our rain chances over the next several days. High temps will trend
back up toward the mid 90s (34-36C) and heat indices in the
triple digits (38C+) will remain possible each day.

&&

.AVIATION...
(00Z TAF Issuance)
Issued at 645 PM CDT Sat Jun 20 2026

Shower and thunderstorm activity has gradually diminished over
southeast TX early this evening. VFR is forecast to remain
prevalent over the region through the evening hours. MVFR ceilings
are expected to develop again overnight into Sunday morning.
Another round of scattered SHRA and possibly a few TSRA should
also develop primarily after 08-10Z and persist into the morning.
We maintained a PROB30 mention for most terminals overnight into
Sunday morning.

&&

.MARINE...
Issued at 1206 AM CDT Sun Jun 21 2026

Scattered to numerous showers and thunderstorms will be possible
through early today. Otherwise, light to moderate onshore flow
will persist through the upcoming week with seas mostly between 3
to 6 ft.

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)  91  78  93  78 /  40   0   0   0
Houston (IAH)  91  80  94  80 /  50   0   0   0
Galveston (GLS)  88  84  90  84 /  50  10   0   0

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...High Rip Current Risk through this evening for TXZ436>439.

GM...None.
&&

$$

DISCUSSION...DL
AVIATION...CLL
MARINE...DL

NWS HGX Office Area Forecast Discussion