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000
FXUS64 KHGX 181737
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1237 PM CDT Thu Apr 18 2024

...New AVIATION...

.SHORT TERM...
(Today through Friday Night)
Issued at 317 AM CDT Thu Apr 18 2024

A consistent onshore flow regime continues to characterize the
synoptic pattern across the region, with warm and humid conditions
prevailing into the weekend prior to the approach of a surface cold
front on Sunday (see Long Term section). For the time being, the
presence of broad surface high pressure over the Southeastern CONUS
and a developing surface low centered over the Oklahoma Panhandle
maintains a moderate southeast wind and thus the steady influx of
warm and moist Gulf air.

A further increase in this afternoon`s highs, driven by increases in
850mb temperatures, persistent WAA, and more scattered cloud
coverage, can be expected. While it`s not particularly likely that
we will approach daily record values, we`ll nonetheless see many
locations reaching the upper 80s inland and the lower 80s along the
immediate coast. Models continue to depict the passage of a few weak
shortwaves embedded within the midlevel flow, but forecast soundings
continue to show the presence of a capping inversion that will work
to inhibit any widespread precipitation.

High resolution models continue to show the approach of a cold front
associated with the aforementioned low this evening, but the
boundary remains expected to stall just to our north. Nonetheless,
given lingering uncertainty regarding the exact progression of the
front, the potential for a few storms across the northern zones
can`t be ruled out should the boundary progress further to the south
than currently expected. As such, have included the mention for a
slight chance of thunderstorms in this morning`s package.

Warm and humid conditions continue to prevail on Friday with highs
yet again reaching the mid/upper 80s across much of the area.
Locations well to the north of I-10 may see a slightly cooler and
drier day depending on the exact progression of the boundary, though
large-scale changes to the overall pattern are not expected until
Sunday. Overnight lows will continue to sit in the upper 60s to
lower 70s.

With humid conditions prevailing for the next several days and
temperatures remaining elevated, most of the area looks poised to
reach WBGT values in the lower 80s. With this being the beginning of
the warmer season and thus heat acclimation being limited at this
time, heat safety actions for those planning any strenuous outdoor
activities may need to be considered.

Cady

&&

.LONG TERM...
(Saturday through Wednesday)
Issued at 317 AM CDT Thu Apr 18 2024

The quasi-stationary frontal boundary will still be hanging around
near the Brazos Valley throughout most of the day on Saturday. It`s
worth mentioning that the global deterministic models keep the front
just north of Southeast TX throughout most of the day, but the
higher resolution NAM shows the front right over the Brazos
Valley/Piney Woods. The preceding zonal flow aloft is the cause of
the front just biding its time before getting a push from an
embedded shortwave trough pushing in from the Four Corners region.
With PW values surging up to 1.8"-2.0" (MAX percentile: ~1.91")
along the frontal boundary, we`ll certainly have plenty of moisture
in place (in addition to various other ingredients) for a heavy
rainfall threat.

The higher rainfall amounts will be focused along a line with the
greatest frontogenetic forcing, which as of the 00Z model suite is
split between either being over the Brazos Valley/Piney Woods or
just north of there. Currently expecting 1-3" of rainfall for the
Brazos Valley, but there are still a few models showing totals of
4+" being possible within the vicinity. It`s just going to be a
matter of where the frontogenetic band sets up as that is going to
hold the higher rainfall rates. The main window for heavy rain will
be late Saturday night/early Sunday morning. The WPC has outlined
the Brazos Valley/Piney Woods in a slight risk of excessive rainfall
(level 2 out of 4) and a marginal risk (level 1 out of 4) elsewhere
generally north of I-10. Locally heavy rainfall could lead to
isolated street flooding especially in low-lying areas and areas
with poor drainage. We`ll also have to monitor for responses along
area rivers/creeks/bayous where the heavy rain falls along with its
subsequent runoff. There may be a few lingering showers into late
Sunday morning/early afternoon, but the bulk of the rain will be
finished early Sunday morning.

This cold front isn`t a strong one by any means, but you`ll
definitely be able to feel its effects. We`ll go from daytime highs
on Saturday in the low to mid 80s to the upper 60s to low 70s on
Sunday. The Saturday night temperature forecast one remains a little
tricky depending on how far south the front sags initially, but for
now we have lows in the mid to upper 50s across the Brazos Valley
and low to mid 60s elsewhere. Sunday night may be the coolest
temperatures we`ll see for at least a week or so with widespread
lows in the 50s. Drier air (PW values ~0.8-1.0") will be fully in
place on Sunday night, but quickly modifies into a more humid
airmass as surface high pressure exits to the east allowing for
onshore flow to return. In addition to that, the synoptic pattern
looks to transition into ridging aloft, so we can expect a warming
trend going into next week. We`ll go from the upper 70s on Monday to
the low 80s on Tuesday and mid 80s on Wednesday...and the warming
trend may not end there. Chances for showers/storms return towards
the end of the long term period with elevated moisture being lifted
by passing embedded shortwaves. This gives off the appearance
of being a sea breeze/diurnal type of convective activity.

Batiste

&&

.AVIATION...
(18Z TAF Issuance)
Issued at 1222 PM CDT Thu Apr 18 2024

South to southeasterly winds and VFR conditions can be expected
this afternoon. Isolated showers may develop in areas along and
south of the I-10 corridor this afternoon, with the occasional
thunderstorm possible at times. MVFR CIGS fill back in this
evening as winds become light, potentially dropping to IFR levels
overnight into the early morning hours of Friday. Light patchy fog
may accompany these CIGS during this early morning period.
Conditions improve after sunrise with fog clearing and CIGS
lifting during the day. Areas along and south of the US-59
corridor could see VFR conditions return during the afternoon on
Friday.

03

&&

.MARINE...
Issued at 317 AM CDT Thu Apr 18 2024

With onshore flow prevailing, an elevated rip current risk continues
through the end of the week along with the potential for
intermittent periods of haze/fog mainly during the evening through
early morning hours. If sea fog develops, it is not expected to be
dense or create significant visibility restrictions. That will all
come to an end once a cold front pushes offshore late Saturday
night/early Sunday morning. Expect the cold front to bring in a
round of showers/storms that may linger into early Sunday afternoon
in the Gulf waters. Moderate northeasterly winds prevail in the wake
of the front before shifting back to southeasterly on Monday night.

Batiste

&&

.HYDROLOGY...
Issued at 317 AM CDT Thu Apr 18 2024

Only one River Flood Warning remains in effect as of early Thursday
morning. The Trinity River at Riverside (RVRT2) crested into minor
flood stage and is now on a slow descent. It is forecast to fall out
of flood stage on Friday afternoon. We`re also continuing to monitor
the Trinity River at Moss Bluff (MBFT2) as its secondary crest is
forecast to reach into minor flood stage on late Friday/early
Saturday. Additional rainfall is expected Saturday/Sunday, but
latest model consensus keeps the higher rainfall amounts just north
of Southeast Texas. It is definitely still worth monitoring though
especially for those in and around the Brazos Valley/Piney Woods, so
stay up to date on the latest forecast.

You can monitor current and forecast conditions at this weblink:
water.weather.gov/ahps2/forecasts.php?wfo=HGX

Batiste

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)  88  68  83  67 /  10  10  10  10
Houston (IAH)  88  71  86  71 /  20  20  10   0
Galveston (GLS)  80  72  80  71 /  20  20  20   0

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&

$$

SHORT TERM...Cady
LONG TERM....Batiste
AVIATION...03
MARINE...Batiste