093
FXUS64 KHGX 112101
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
401 PM CDT Sat May 11 2024

...New SHORT TERM, LONG TERM, MARINE, HYDROLOGY...

.SHORT TERM...
(This evening through Sunday Night)
Issued at 346 PM CDT Sat May 11 2024

Some light showers/virga has been moving through the area this
afternoon, but all-in-all a relatively quiet day with seasonal
temperatures and breezy easterly winds. This quiet stretch ends this
evening as showers and thunderstorms begin to pop-up. Activity
begins to ramp up overnight tonight through Sunday night as a train
of weak shortwaves/vort maxes slide through E Texas. Exactly where
the storms develop tonight is a bit uncertain with CAM guidance
firing off storms at either the coast or across the B/CS area. The
vast difference in location is likely due to lingering mesoscale
features that develop this afternoon/evening. PWATs tonight will be
around 1.8-2.1", so the storms that develop tonight will have a
chance of producing localized downpours. As we enter into Sunday
morning, the showers and thunderstorm activity will be predominately
within the B/CS area out through the Pineywoods region as a larger
upper level low begins to cross through the Plains. Showers and
thunderstorms will remain likely through the evening hours with
lingering isolated storms into Monday morning.

Unfortunately yet again, it looks like the heaviest rainfall will
fall over the Pineywoods region. Generally up to around 2-4" of rain
will be possible through Monday morning, but the HREF LPMM has been
showing isolated amounts of 6" possible. Rain totals decrease
further south with generally up to 0.5-2" south of I-10, and the
showers and thunderstorms will be more hit-or-miss so some locations
may see no precipitation. WPC has placed the northern half of
Houston County in a Moderate Risk (level 3/4) in a Moderate Risk of
Excessive Rainfall, a Slight Risk (level 2/4) down to I-10, and a
Marginal Risk (level 1/4) down to the coast. The 1 and 3 hour FFG
within the Pineywoods region is only around 2-3", so the additional
heavy rainfall may be quick to produce minor flooding or flash
flooding. A Flood Watch has been issued for Houston, Trinity, Polk,
San Jacinto, Walker, and Madison counties Sunday morning through
Monday morning. Portions of the Trinity and Brazos Rivers remain in
flood from the previous heavy rain events, and this additional
rainfall may result in additional rises. More on this in the Hydro
section below.

To put into perspective how wet the Pineywoods region has been this
year, Huntsville has had 45.16" of rain so far this year. The normal
total for the *entire year* is 43.65".

In addition to the flood threat, there is a chance for isolated
strong to severe thunderstorms Sunday afternoon into Sunday night.
The southeasterly fetch will pump CAPE values of up to around 2000-
2500 J/kg with EBWD values around 40-50kt, so there will be fuel in
place for storms to tap into. The cap should be strong enough for
areas south of Conroe to prevent severe storm development, but the
cap is a bit more susceptible northwards. SPC has increased the
Severe Weather Outlook for tomorrow to include most of SE Texas in
Marginal (level 1/5) and a Slight Risk (level 2/5) for areas north
of Conroe. Large hail and strong winds would be the main concern
*if* severe storms develop, but cannot out-rule a brief tornado
either. The strong to severe thunderstorm threat continues into
Monday, but more on that in the Long Term below.

Low temperatures tonight will be in the upper 60s to low 70s, but
the more southeasterly flow Sunday night will bring overnight lows
into the low to mid 70s area-wide. High temperatures on Sunday will
be close to seasonal with areas along and south of I-10 in the low
to mid-80s. The Pineywoods region will be slightly cooler thanks to
the showers and thunderstorms with highs only into the mid to upper
70s.

Fowler

&&

.LONG TERM...
(Monday through next Friday)
Issued at 346 PM CDT Sat May 11 2024

The stormy weather pattern is expected to continue through at
least Monday evening. Upper level disturbances embedded in the
base of the an upper level trough moving over the Southern Plains
will be move over Southeast Texas throughout the day as a cold
front makes it way south southeast from the central Texas region.

On Monday morning, periods of isolated to scattered activity will
be possible. However, will depend on how strong the cap is and
how much low level moisture decreases during the overnight hours.
As stated, although a slight decrease in low level moisture could
occur Sunday night into Monday morning, global models show
another period of moisture convergence over our area late Monday
morning into Monday evening as moisture transport continues and
the cold front approaches the Brazos Valley and Piney Woods region
and PWs could rise back into the 1.8 to 2.1 inches range.
Forecast soundings continue to indicate CAPE values between 3000
to 4500 J/kg over much of the region for the afternoon to early
night hours, with the highest values situated over areas north of
the I-10 corridor. They also depict steep mid level lapse rates,
SFC-6km shear values between 40-50 knots, PWs of 1.8 to 2.0 inches
and dewpoints in the mid 70s. This set up also occurs as a couple
of vort maxes move across our area. Oh and let`s not forget that
we will also have added lift from the approaching cold front to
consider as well.

Thus, overall, confidence of Monday being another stormy and wet
day continues to increase. There is the potential for periods of
locally heavy rainfall, which could result in flash flooding and
additional rises along small creeks and rivers. WPC`s EXcessive
Rainfall Outlook continues a Slight Risk (threat level 2 out of 4)
for areas southeast of the Brazos Valley and a Marginal Risk
(threat level 1 out of 4) for the rest of Southeast TX. Our
estimated rainfall totals from Sunday into Monday are generally
2-4 inches with isolated higher amounts over areas north of I-10
and 1-2 inches with isolated amounts elsewhere.

There is also the potential for strong to severe thunderstorms
capable of producing large hail and damaging winds. Although
conditions are not ripe for tornadoes, a brief tornado or two
cannot be ruled out. SPC continues a Slight Risk (threat level 2
out of 5) for severe thunderstorms for all of Southeast TX.

Shower and thunderstorm activity is expected to end Monday
evening into Monday night from northwest to southeast as the cold
front pushes across the region. We should start to see
improvements over the Brazos Valley near sunset and end over the
coastal areas near midnight. A respite in storms is expected on
Tuesday and Tuesday night as drier air filters in behind the cold
front.

Isolated showers are possible on Wednesday afternoon and
Wednesday night as moisture from the Gulf begins to move back into
the region and a mid to upper level disturbance moves over Texas.
Rain chances will increase on Thursday, as disturbances move
aloft, moisture rises, good instability is in place, a warm front
moves over the region followed by the approach of another cold
front. Although it is too early to say how much rain or how strong
storms can be on Thursday, guidance is hinting at another set up
for periods of heavy rainfall and strong storms. Stay tuned.

Conditions will improve sometime Thursday night into Friday
morning as the cold front moves across Southeast Texas. At this
time, tranquil conditions look to prevail through the upcoming
weekend.

Cotto (24)

&&

.AVIATION...
(18Z TAF Issuance)
Issued at 1223 PM CDT Sat May 11 2024

VFR conditions will prevail through the afternoon, but MVFR to IFR
conditions will develop this evening and continue through Sunday
morning at least. CIGs will drop to around 1500 to 2500ft between
sunset and midnight from south to north. CLL and UTS will also
have the chance to see CIGs around 700-800ft by sunrise Sunday
along with some patchy fog. Breezy easterly winds today will
diminish tonight, then become breezy southeasterly winds through
the day on Sunday.

There will be scattered showers with the potential of isolated
thunderstorms this afternoon through Sunday morning - but
determining exactly where they will develop is not known. Areas
along the coast will have the best chance this afternoon, moving
up through SGR/HOU this evening, up towards IAH around midnight,
and then potentially to UTS/CLL late tonight. But again,
confidence is not high on the location of these storms, so have
done with mainly PROB30 TS groups at this time. There will be a
lull during tomorrow morning, but will see some redevelopment of
showers and storms tomorrow afternoon/evening. Highest coverage
of these storm will stay north of CXO, but may see some isolated
showers and storms down to the I-10 corridor.

Fowler

&&

.MARINE...
Issued at 346 PM CDT Sat May 11 2024

Moderate to occasionally strong east winds and seas of 3 to 5
feet will continue through tonight. Small Craft will need to
continue to proceed with caution. Moderate onshore flow is
expected Sunday and Monday. A cold front will move into the
coastal waters Tuesday morning and will result in variable winds
on Tuesday. Onshore flow could return quickly on Tuesday evening
and is expected to continue through Thursday. Another cold front
is expected to push across the region sometime early Friday
morning. Moderate east southeast winds expected during the
upcoming weekend.

Periods of showers and thunderstorms can be expected tonight through
Monday night, some could be strong at times. Another round of
showers and storms can be expected on Thursday and Thursday night.

Cotto (24)

&&

.HYDROLOGY...
Issued at 346 PM CDT Sat May 11 2024

A Flood Watch will go into effect Sunday morning through Monday for
portions of the Piney Woods due to additional rounds of heavy
rainfall. This rain is expected to fall in an area that received an
excessive amount of rain from last week`s events, so the soils
remain fairly saturated. This means that rainfall will become runoff
quickly leading to additional responses along area
rivers/creeks/bayous. Flash flooding is also a possibility in these
locations. Widespread amounts of 2-4" are expected with isolated
totals of 6+" possible in the watch area.

Minor to major river flooding continues for parts of Southeast
Texas, particularly along portions of the Trinity and Brazos rivers.
The following river points remain in flood stage as of Saturday
afternoon:

- Trinity River (Liberty): Major Flood Stage
- Trinity River (Riverside): Moderate Flood Stage
- Trinity River (Moss Bluff): Moderate Flood Stage
- Brazos River (West Columbia): Moderate Flood Stage
- Trinity River (Crockett): Minor Flood Stage
- Trinity River (Goodrich): Minor Flood Stage
- Brazos River (Richmond): Minor Flood Stage
- Brazos River (Rosharon): Minor Flood Stage
- Brazos River (Sugar Land): Minor Flood Stage

Remember to heed any instructions from your local officials and to
never travel through ANY flooded areas or roadways. TURN AROUND,
DON`T DROWN. Please monitor updated forecasts via the NWS AHPS
website and/or the new NWS NWPS webpage (https://water.noaa.gov/) as
the river flood threat continues.

Batiste

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)  68  81  71  85 /  40  70  50  60
Houston (IAH)  70  82  74  87 /  30  60  40  60
Galveston (GLS)  74  82  76  83 /  30  40  30  50

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...Flood Watch from Sunday morning through Monday morning for
     TXZ163-164-176>179.

     High Rip Current Risk through Sunday evening for TXZ436>439.

GM...Small Craft Advisory until 7 PM CDT this evening for GMZ330-335-
     350-355-375.

     Small Craft Should Exercise Caution from 7 PM this evening to
     midnight CDT tonight for GMZ330-335-350-355-375.

     Small Craft Should Exercise Caution until midnight CDT tonight
     for GMZ370.

&&

$$

SHORT TERM...Fowler
LONG TERM....24
AVIATION...Fowler
MARINE...24
HYDROLOGY...Batiste