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395
FXUS64 KHGX 131127
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
627 AM CDT Mon Apr 13 2026

...New AVIATION...

.KEY MESSAGES...

- The Flood Watch has been cancelled early. Scattered showers and
  storms remain possible overnight especially around the Brazos
  Valley and the Piney Woods.

- Increasingly summer-like weather by the second half of the week.

- Rain chances increase next weekend as a cold front moves into
  the region.

&&

.DISCUSSION...
Issued at 1018 PM CDT Sun Apr 12 2026

Well that escalated quickly...multiple rounds of heavy rain led to
instances of flooding across portions of Southeast Texas generally
along and north of the I-10 corridor. Areas from northern Colorado
County through northwestern Harris County received 3-5+" of rainfall
with rainfall rates peaking above 4" per hour at times. For more on
today`s rainfall and its impacts on area streams/rivers, see the
Hydrology discussion down below. The environment is fairly worked
over following this afternoon`s convection, so the probability of
another round of rain of similar caliber overnight are on the slim
side. That being said, PW values remain above the 90th percentile
(~1.53"). With additional embedded shortwaves passing through,
remnant boundaries lingering from earlier convection, a nearby
25-30 kt LLJ, and elevated low-level moisture remaining in place,
we certainly have the ingredients for scattered showers and storms
overnight. This is most likely to occur north of the Brazos
Valley/Piney Woods. We`ll continue to monitor radar and model
trends. As I write this (around 10pm CDT), I`m looking at a
cluster of storms in central Texas moving southeastward and storms
just northwest of the Brazos Valley tracking northeastward. The
hope is that northeastward moving convection works over the
environment before the southeastward moving convection moves in to
allow for a quieter night for us. That wasn`t confusing at all to
describe!

As a result, the flood threat overnight remains rather conditional
as it`ll depend on if additional convection is able to move into
our area. The latest trends of the CAMs keeps the bulk of the
nocturnal convection to the north of the Brazos Valley, but
they`ve been a bit wishy washy on the placement of convection
throughout the day. There remains a slight risk (level 2 of 4) of
excessive rainfall for most of Southeast Texas (except right along
the coast) as a result. Just remember that this is a conditional
threat as all of the favorable ingredients remain in place. It`s
just a matter of if convection manages to move into the area and
sustain itself. Since confidence is not too high on this playing
out, the Flood Watch for Southeast Texas was cancelled early. Some
of the CAMs do bring some convection into the Brazos Valley/Piney
Woods overnight, so the chances definitely aren`t zero for
isolated instances of minor flooding.

Going into the work week, we remain in a pattern with southwesterly
flow aloft with embedded shortwaves bringing occasional chances for
showers and storms around midweek in our northern counties. May have
to watch for an isolated storm or two developing to our west on
Monday afternoon as it could potentially drift eastward into our
area. As an upper level trough sweeps through the central CONUS
around midweek, it will aid in the development of storms off of a
dry line over in western Texas. It`s not entirely out of the
question for a few storms to clip portions of the Brazos
Valley/Piney Woods, but there will be a cap that needs to be
overcome (especially on Tuesday). PW values begin to increase
towards the end of the work week as moisture converges along a
frontal boundary that stalls out to our north, so some isolated
streamer showers will be possible. Speaking of frontal boundaries,
we`re monitoring the potential for a cold front next weekend. Now
it`s too early to say it`s a sure thing one way or the other...but
the NBM temperature envelope (e.g. all percentiles) do trend
slightly downward so that`s something! We can take a look at things
probabilistically as well...the probability of high temperatures
below 80 degrees increases sharply to 60-90% range in the latter
half of next weekend. Plenty of time for things to change and
evolve, but this does look to be our next best chance of rain as
well.

Speaking of temperatures, they will go a gradual upward trend
throughout the week with highs on Monday mainly in the low 80s then
in the mid to upper 80s by midweek and solidly in the upper 80s by
the end of the work week. Isolated spots reaching the 90 degree mark
aren`t entirely out of the question either towards the end of the
week. Low temperatures will mainly be in the upper 60s to the low
70s throughout most of the forecast period. We already discussed the
potential cold front in the paragraph above, so we`ll let that speak
for itself even though I`m sure y`all wouldn`t blame me if we talked
about it twice! :)

Batiste

&&

.AVIATION...
(12Z TAF Issuance)
Issued at 617 AM CDT Mon Apr 13 2026

MVFR CIGS this morning should scatter/lift with VFR conditions
returning by the late morning/afternoon. Breezy south to southeast
winds are expected during the daytime, later easing down this
evening. Isolated showers will also be possible throughout the
day, though rain chances are too low to warrant a mention in the
TAFs. MVFR CIGs fill in again overnight into Tuesday. IFR CIGs
could briefly develop during this early morning period as well.

03

&&

.MARINE...
Issued at 1018 PM CDT Sun Apr 12 2026

Moderate southeasterly winds and elevated seas (4-6 ft) persist, so
small craft should continue to exercise caution through at least
Monday morning. Southeasterly winds weaken a bit early this week,
but there may be intermittent periods where caution flags may be
necessary. Due to the persistent onshore flow, slightly elevated
water levels during high tides remain possible. P-ETSS guidance
continues to reflect water levels reaching 2.5-3.0 ft above MLLW
during times of high tide throughout most of the work week. While
coastal flooding is not a concern at this time, some wave run-up is
certainly possible along Gulf-facing beaches along with increased
risk of rip currents.

Batiste

&&

.HYDROLOGY...
Issued at 1018 PM CDT Sun Apr 12 2026

Clusters of strong storms began to move into northern Colorado
County early this afternoon and gradually drifted east-northeastward
into northwestern Harris County. These storms were slow-moving at
times with rainfall rates peaking above 4" per hour in the heaviest
downpours. Storm total QPE shows an axis of high rainfall totals
extending from northern Colorado County to southern Austin/Waller
Counties and into northeastern/northern Harris County. The highest
rainfall totals peaked in the 4-5" range with the winners of the day
being 5.08" in southern Waller County just north of Pattison and
5.34" in northwestern Harris County near Jersey Village. This led to
instances of street flooding across this corridor with numerous
reports (pictures, images, etc.) sent in. Thankfully, there were no
reports of flood waters entering any homes or structures.

This heavy rainfall also led to isolated instances of flood gauges
reaching, or expected to reach, action stage. Langham Creek at
Addicks is already in action stage this evening. Bedias Creek at
Madisonville, Davidson Creek at Lyons, and the Lavaca River at
Hallettsville are all forecast to crest in action stage over the
next day or so. Some of these forecasts are based off of QPF, so the
forecast may change based on radar/model trends. Remember that you
can monitor updated river forecasts via the NWS NWPS webpage
(https://water.noaa.gov/).

There is potential for additional rounds of rainfall overnight
into early Monday morning. In Southeast Texas, this is most likely
to occur over the Brazos Valley/Piney Woods which is well north of
the axis of high rainfall totals. Isolated instances of minor
flooding cannot be completely ruled out though. The Flood Watch
was cancelled since confidence isn`t high on this occurrence.

Batiste

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)  83  68  84  69 /  30   0   0   0
Houston (IAH)  83  70  84  70 /  30   0  10   0
Galveston (GLS)  79  73  79  73 /  10   0  10   0

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...Small Craft Should Exercise Caution until 7 AM CDT this morning
     for GMZ330-335-350-355-370-375.

&&

$$

DISCUSSION...Batiste
AVIATION...03
MARINE...Batiste

NWS HGX Office Area Forecast Discussion