Flash Flood Warning 8, NWS Houston/Galveston, TX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
648 PM CDT Sun Jun 14 2026

...New AVIATION...

.KEY MESSAGES...

- Rounds of showers and thunderstorms will persist through the
  next few days. Rainfall totals of 2 to 4 inches is forecast,
  with locally higher amounts of 6-8 inches possible in the more
  organized storms. Flash flooding is possible, especially as we
  head towards Tuesday.

- After a brief break from the heat and humidity on Monday and
  Tuesday, dangerous heat builds back in by midweek. Peak
  afternoon temperatures will rise into the low to mid 90s (31-36
  Celsius) with peak heat indices near 103-107 (39-42 Celsius).

- Moderate to high risk of rip currents this weekend, likely
  continuing into portions of next week with elevated high tides.

&&

.DISCUSSION...
Issued at 207 PM CDT Sun Jun 14 2026

A bit of an active pattern is taking shape over the area, as deep
Gulf moisture continues to filter through the area. That,
combined with outflow boundaries from earlier storms, has allowed
for scattered to numerous showers/storms. Despite weaker upper
level flow, so far storms have been moving quickly enough, and
rainfall rates are low enough to not cause any flooding concerns
for now. Outside of thunderstorms, the heat continues to build,
with heat indices climbing into the triple digits. The storm
activity will start to weaken and diminish later this evening,
with the loss of daytime heating.

Rain chances really begin to increase early on Monday, as a
frontal boundary drifts southward and provides a renewed focus for
convection. Given the abundance in moisture (PWs near the
climatological max), rainfall will be heavy at times and the flash
flooding potential will increase, especially in areas that see
the multiple rounds of heavy rain. This will increase further by
Tuesday, as the aforementioned boundary drifts further south and
our moisture continues to increase. Although there isn't a lot of
upper level forcing, instability will remain high so robust
thunderstorms are still possible. In the more organized storms,
rainfall rates could exceed 2 inches at times. Despite drier
soils, these rates will fall as mostly runoff, increasing the
threat for flash flooding. That said, there remains some
uncertainty with regard to where the heavier precip falls and
refinements to the totals are likely over the next couple of days.
There is enough confidence in flash flooding to warrant a Flash
Flood Watch, which is in effect through Wednesday morning.

Areas that don't see a lot of rain, or if there are larger breaks
during peak heating, will have the potential for dangerous heat.
This will especially be the case Wednesday and onward, as rain
chances increase. While high temperatures may only reach into the
lower 90s, RHs will remain elevated and heat indices will approach
the 105-108 degree range. Additionally, overnight lows will be
quite warm towards the end of the week, as lows only fall into
the upper 70s to 80 degrees. This will make overnight relief hard
to come by and heat concerns will increase during the latter half
of the week.

One caveat to the forecast, especially during the middle of the
week, as low pressure develops over SE TX/northern Mexico early
in the week. Guidance is fairly consistent on this low developing
and tracking eastward; however, there remains discrepancies in
the location and timing of the surface low. At this point, the low
will move over the area on Wednesday, during the latter half of
the week, which would mean higher rain chances and a renewed
potential for flash flooding. This is conditional on where the
low tracks, but it's something to monitor in the coming days.

&&

.AVIATION...
(00Z TAF Issuance)
Issued at 628 PM CDT Sun Jun 14 2026

Showers and thunderstorms along and north of I-10 are currently
moving NE should being to weaken in the next few hours. Winds are
generally out of the S/SSE and become light and variable
overnight. Expect a lull in precipitation this evening and
overnight, before ramping up again tomorrow morning. As the
frontal boundary pushes south,from early tomorrow morning through
tomorrow evening, expect scattered to numerous showers and
thunderstorms at terminals throughout the day. As for CIGS, an IFR
deck is expected to move in from the north tomorrow morning,
mainly effecting KCLL, KUTS, and KCXO. Elsewhere, MVFR CIGS are
expected tomorrow morning before lifting to low-end VFR in the
afternoon.

&&

.MARINE...
Issued at 200 PM CDT Sun Jun 14 2026

Light to occasionally moderate onshore winds and seas of 3 to 6 feet
are expected through early next week. Scattered showers and
storms become more widespread overnight through Monday as a weak
front stalls out over SE Texas. A passing disturbance along the
Texas coast will bring moderate to strong onshore winds and higher
seas early Wednesday through Friday afternoon. Continued onshore
flow will result in a moderate to high risk of rip currents with
elevated tides around 3.1- 3.6 ft (MLLW).

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)	  75  83  73  85 /  70  80  60  70
Houston (IAH)			  78  86  75  84 /  50  80  80  90
Galveston (GLS)			  83  88  79  86 /  20  40  80  90

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...Flood Watch through Wednesday morning for TXZ163-164-176>179-
     195>200-210>214-226-227-235>238-300-313-335>338-436>439.

     Beach Hazards Statement through Monday morning for TXZ436>439.

GM...None.
&&

DISCUSSION...JTC
AVIATION...MLG
MARINE...JTC