Flash Flood Warning 41, NWS Houston/Galveston, TX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
130 PM CDT Wed Sep 2 2026

...New AVIATION...

.KEY MESSAGES...

- Tropical Depression Edouard will continue to bring a significant
  threat for heavy rainfall across the Piney Woods for the next 24
  hours.

- Additional rainfall amounts of 2 to 6 inches will be possible in
  areas that have already received significant rainfall.

- Scattered afternoon sea breeze showers and thunderstorms will be
  possible through the end of the week.

&&

.DISCUSSION...

&&

.SHORT TERM...
(This evening through Thursday Night)
Issued at 104 PM CDT Wed Sep 2 2026

The main concern this afternoon through Thursday will be continued
very heavy rainfall from the remnants of Tropical Depression Edouard.
Latest radar and satellite imagery indicates that the center of the
depression is located over eastern Houston County just east of
Crockett with GOES derived PW values approaching 2.3 inches in this
area. With weak mid and upper level steering flow noted, the system
will tend to meander slowly westward over the next 24 hours as mid
level ridging over the eastern CONUS begins to expand westward.
Until then, focused low level convergence in the vicinity of the
circulation will continue to support a re-invigoration of
convection periodically over the next 24 hours. Visible satellite
imagery confirms this with an expansive congested cumulus field
around the western periphery of the circulation. Radar imagery
also supports an uptick in convective intensity over the last hour
likely corresponding to increasing instability due to afternoon
heating. The main threat will be locally intense rainfall in the
convective bands wrapping around the circulation, mainly across
parts of Houston and Trinity Counties in the immediate short term.
Additional rainfall amounts of 2 to 6 inches will be possible
over the next 24 hours near the center of the circulation with
isolated spots picking up 10 inches through Thursday.

Additionally, low level convergence to the south of the circulation
may peak late this afternoon along and just north of the I-10
corridor aided by a weak sea breeze. The sea breeze influence may be
limited somewhat by the broader flow around the center of Edouard,
but high resolution guidance is signaling an uptick in convection in
a narrow band in this area. While heavy rainfall would certainly be
a concern in this area based on the potential for training over a
more urban area, the convection itself would likely be more robust
given ample mixed layer instability >2000 J/kg.

We'll have the highest PoPs (~100%) near the center of the
circulation across our far northern counties through late this
evening with an increase in PoPs (20-50%) along and just north of I-
10 late this afternoon and early evening. Otherwise, convection
should be tied closely to the center of circulation overnight
tonight. The remnant circulation should track farther west on
Thursday with additional rain chances mostly across our north and
northwest counties. Scattered afternoon sea breeze activity is
expected and we'll maintain some storm chances farther south through
the afternoon.

Dunn

&&

.LONG TERM...
(Friday through next Tuesday)
Issued at 104 PM CDT Wed Sep 2 2026

By Friday, the low level circulation will largely be absorbed into
the mean flow, but a pronounced weakness in the 700-500 mb heights
will linger south of an expanding ridge axis. There will likely be
some weak forcing for ascent tied to the mid level disturbance and
with precipitable water values still above 2 inches, we should see
additional widely scattered afternoon showers and storms tied to an
active sea breeze. PoPs will remain relative high both Friday and
Saturday to account for this. While the upper ridge does expand
westward through the weekend, its influence will primarily be across
the Southern Plains leaving a deep easterly flow in place across
southeast TX. Ample deep layer moisture and a lack of broad upper
subsidence should support daily afternoon storm chances into next
week.

Dunn

&&

.AVIATION...
(18Z TAF Issuance)
Issued at 129 PM CDT Wed Sep 2 2026

As TD Edouard passes to our NW, we can expect occasional bands of
showers and thunderstorms with MVFR cigs/vis to impact most of
our TAF sites. Within more intense SHRA, gusts of 20 to 25 kts can
occur. CAMs are honing in on a band of SHRA, with potential TSRA,
to impact the TAF sites along and north of I-10 within the 20 to
03Z period. Since uncertainty remains regarding the coverage and
intensity of these storms, PROB30s were used. Past 03Z, VFR
conditions prevail until another round of rain from the remains of
Edouard arrives. While significant uncertainty remains concerning
the timing and intensity of this second round of rain, there is
enough of a signal in the CAMS to place a PROB30 with MVFR
cigs/vis and -SHRA for the most northern TAF sites in the 12Z to
18Z period. There is potential for the MVFR cigs/vis to reach IAH,
but confidence is too low to include it currently. To account for
rain reaching further south, PROB30s with SHRA were included for
tomorrow morning and afternoon for IAH, HOU, and SGR. Winds will
generally be out of the SE throughout today before turning more S
overnight and Thursday.

JMG

&&

.MARINE...
Issued at 104 PM CDT Wed Sep 2 2026

Southwest winds around the broader circulation of TD Edouard will
gradually give way to onshore flow later today and tonight. Winds
will generally be around 10 kt with intermittent higher gusts
especially in scattered thunderstorms. Seas 2 to 3 feet will become
1 to 2 feet later tonight through the end of the week. Low storm
chances will persist into next week.

Dunn

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)	  76  93  75  95 /  30  40  20  30
Houston (IAH)			  79  92  78  94 /  50  50  20  60
Galveston (GLS)			  84  91  83  91 /  10  30  30  30

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...Wind Advisory until 7 PM CDT this evening for TXZ163-164.

     Flood Watch through Thursday morning for TXZ163-164-176>179-196-
     198>200-212-213-300-313.

GM...None.
&&

DISCUSSION...Bailey
AVIATION...JMG
MARINE...Bailey