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National Weather Service Forecast Discussion

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140
FXUS64 KHGX 151201
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
601 AM CST Sun Nov 15 2026

...New UPDATE, AVIATION...

.KEY MESSAGES...

- A storm system will bring multiple weather hazards Sunday

- There is a risk of strong to severe thunderstorms today in our
  coastal and marine areas.

- Heavy showers and thunderstorms may result in localized flash flooding
  today, especially near the coast.

- Strong marine winds expected through Monday. Gales Warning in
  effect for Galveston Bay and the Gulf waters. Small Craft
  Advisory in effect for Matagorda Bay.

&&

.UPDATE...
Issued at 601 AM CST Sun Nov 15 2026

Lead shortwave that brought areas of light rain overnight is
pushing ewd into Louisiana. There is a zone of low level
convergence near the coast where we`re seeing moderate rain along
the beaches in Matagorda and Brazoria Counties that have produced
1-3" so far. Attention turns to the next batch of rain across
north and north-central TX will be making its way across the
region during the day today. Overall model trends have been more
progressive...so although some localized heavy downpours can be
anticipated, continued sewd movement should somewhat limit the
excessive totals. The warm sector probably won`t make it too far
past the beaches which should also help in terms of rain total
inland. But still concerned about the coastal counties where
totals should be highest. Keep in mind that tide levels are up, so
drainage will be slow.

I bumped up the start time of the Gale Warnings for our eastern
waters (Galveston Bay and adjacent Gulf) to begin immediately.
HRRR has been consistently showing the gradient tightening
faster...and we`re seeing that in current observations with
30-37kt already showing. Look for these speeds to increase further
by mid morning. Still anticipating the highest speeds this evening
and tonight when some 45kt gusts can`t be ruled out over the
waters. 47

&&

.DISCUSSION...
Issued at 1130 PM CST Sat Nov 14 2026

A variety of weather hazards will effect southeast Texas on
Sunday. A mid/upper low is currently pushing into the Texas
Panhandle and drifting eastward towards Oklahoma. A strengthening
and increasingly diffluent mid/upper jet is located ahead of and
to the south of the low. These ML/UL dynamics are also helping to
foment LL cyclogenesis, with a developing sfc low over NW Texas
(south of the Panhandle). Meanwhile, a rather cold sfc high is
drifting southeastward over the Mississippi River Valley. Colder
dense air from the east is advecting westward towards the low, and
enhancing a temperature gradient across the Lone Star State. The
sfc low will track southeastward Sunday, roughly parallel to the
temperature gradient. To the north of the low`s associated warm
front, one can expect widespread light to moderate showers, with
some embedded heavier showers and thunderstorms. But those south
of the warm front will find themselves in the system`s warm
sector, where high atmospheric buoyancy coupled with a strongly
sheered and veering vertical wind profile will set the stage for
stronger thunderstorms. As discussed in my discussion yesterday,
there was some uncertainty regarding the exact placement of these
boundaries and the overall extent of the warm sector over our CWA.
But today, it appears there is increasing confidence that the
warm front will be more suppressed southward, limiting the warm
sector zones to the coast (especially near Matagorda Bay) and the
offshore Gulf waters.

Through the early morning hours on Sunday, the highest chance of
showers will be across our western counties. There is a risk
strong to severe thunderstorms in the vicinity of Matagorda Bay
overnight into Sunday morning. Already, we have observed discrete
supercells offshore the Coastal Bend this evening, with some
"side lobe-y" looking cells offshore of Matagorda. Therefore, I am
not going to be surprised if we manage to see a few waterspouts
in our Gulf waters in the vicinity of Matagorda before most people
wake up on Sunday. We also cannot rule out a tornado in this area
either. Rain and thunderstorm coverage should generally increase
over our region later this morning and into the afternoon. With
trends pointing towards a farther south warm front, it`s quite
possible that most (maybe all) areas north of I-10 will hold in
the 50s all day. There`s even some hi-res guidance suggesting our
northern zones could drop into the 40s by late afternoon. There
will likely be a steep temperature gradient south of I-10. The
warmest parts of our CWA (coastal areas of Brazoria, Matagorda,
and Jackson Counties) could top out in the 70s.

The highest risk of heavy rainfall capable of flooding will be
near the coast. However, locally heavy rainfall capable of
localized flooding cannot be ruled out farther inland. Widespread
totals of 1-2 inches are expected inland, while coastal areas are
forecast to average in the 2-4 inch range. Locally much heavier
totals are likely at the coast, with some spots possibly receiving
over 6 inches of rainfall. The highest rainfall rates are still
expected to peak 2-3"/ per hour near the coast. Therefore, flash
flooding is a concern.

Rain and thunderstorms are not the only hazards associated with
this system. Strong, gusty coastal and marine winds will continue
through Monday. There is even a Gale Warning in effect for the
majority of our marine zones for later today into Monday. Please
see the marine discussion for more details.

Colder air should push southward towards the coast as the low
exits offshore, resulting in breezy and chilly conditions Sunday
night. Lows are expected to be in the 40s north of I-10, with low
to mid 50s farther south. Yesterday, Monday was appearing murky
and quite chilly. Today, there`s increasing uncertainty regarding
how murky it will be on Monday. Some of the guidance is suggesting
a shorter isentropic lift period and more dry air than initially
expected, opening the door to breaking clouds and more sunshine.
If the sun breaks out by early/mid afternoon, then we may make a
run for the 60 degree mark. But if clouds prove more resilient,
then I could see us struggling to warm past the mid 50s. Monday
night will be chilly, with widespread lows in the 40s. Areas near
the coast and within the heart of Houston`s urban heat island may
remain in the 50s.

We still anticipate a warming trend beyond Monday. By Wednesday
and Thursday, most of the region is expected to be in the 70s.
Couldn`t rule out a few locations reaching 80 by week`s end.

Self

&&

.AVIATION...
(12Z TAF Issuance)
Issued at 601 AM CST Sun Nov 15 2026

With the exception of coastal areas, we`ll see a brief break in
precipitation until a band of rain and embedded storms to our
northwest tracks across the region later this morning and off the
coast late in the day. Stronger, embedded cells will be capable of
producing some heavy downpours, reduced visibility, and gusty
winds. Ceilings are currently mixed, but look for things to trend
down into MVFR territory this morning and eventually IFR as the
day and evening progresses. Moderate rain should come to an end
over all locations by early evening, but we`re looking for some
wrap around drizzle/light rain during the overnight hours. Can`t
rule out some ceilings 238-313-335>338.

     Beach Hazards Statement through Monday morning for TXZ436>439.

     Wind Advisory until 6 PM CST Monday for TXZ436>439.

GM...Small Craft Advisory until 3 PM CST Monday for GMZ330.

     Gale Warning until 6 AM CST Monday for GMZ335.

     Small Craft Advisory from 6 AM to 3 PM CST Monday for GMZ335.

     Small Craft Advisory until 6 PM CST this evening for GMZ350-370.

     Gale Warning from 6 PM this evening to 3 PM CST Monday for
     GMZ350-370.

     Gale Warning until 3 PM CST Monday for GMZ355-375.

&&

$$

DISCUSSION...Self
AVIATION...47
MARINE...Self

NWS HGX Office Area Forecast Discussion