959
FXUS64 KHGX 152052
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
352 PM CDT Sat Jun 15 2024

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

.SHORT TERM...
(This evening through Sunday Night)
Issued at 232 PM CDT Sat Jun 15 2024

The remainder of the weekend will continue to be characterized by
warm, humid, but otherwise seasonable conditions before things
become quite a bit more active next week (see Long Term section
below). In general, the synoptic pattern has remained fairly
steady with a surface high centered over the SE CONUS and broad
low pressure located near the Yucatan Peninsula. This will
continue to promote a light to moderate SE flow which will supply
a steady stream of Gulf moisture to the area. Look for overnight
lows tonight to sit a couple of degrees higher as a result of
sustained WAA, with inland locations in the mid 70s and the
immediate coast likely remaining around 80-82.

A mild tightening of the surface pressure gradient will increase
onshore winds somewhat heading into Sunday, resulting in the
approach of a plume of deeper Gulf moisture (PWs increase to ~1.75
in). This increase in moisture may be sufficient to support some
isolated thunderstorm activity mainly driven by diurnal heating,
but overall rainfall coverage will not become particularly
widespread prior to the arrival of more conducive upper level
support heading into the early part of next week. High
temperatures once again will approach the mid 90s, with overnight
lows a touch higher as greater moisture leads to an increase in
overnight cloud coverage.

Cady

&&

.LONG TERM...
(Monday through next Friday)
Issued at 232 PM CDT Sat Jun 15 2024

On Monday, a surface low is progged to spin up over the Rockies,
deepening later in the week as an upper trough digs in over the
Northwestern CONUS. With surface high pressure spanning the eastern
sea board, this should tighten the pressure gradient, increasing
onshore flow over the region. Combined with an upper level trough
overhead, this will funnel humid Gulf air into SE Texas, creating a
corridor of deep moisture (+2" PWs) and numerous shortwave impulses
passing aloft. The end result will be wetter conditions with rounds
of showers/thunderstorms possible throughout the upcoming week. The
upper level trough axis appears to be slightly further west in
comparison to yesturday`s model runs. Consequently, this seems shift
the "train" of shortwave impulses further into SE Texas, steering
heavier storms/rainfall into our area. Global models now suggest
that a coastal trough will develop off the Deep S Texas Coastline on
Tuesday. This disturbance looks to track northward overnight, moving
over SE Texas on Wednesday. A 30-40 knot LLJ looks to accompany this
trough, bringing strong winds along the coast and likely further
amplifying rainfall totals. Forecast soundings through mid week
still show ample instability and saturated conditions indicative of
high precipitation efficiency. Cloud layer winds and Corfidi upshear
winds skew lower (more-so early in the week) suggest slower moving
storms will could further amplify the potential for locally heavy
rainfall.

With all those factors in consideration, WPC has a Slight (level
2/4) Risk of excessive rainfall across portions of SE Texas for
Monday, Tuesday and Wednesday. Any storms that develop during this
period may be slower-moving in nature, capable of producing locally
heavy rainfall. This heavy rainfall threat looks to be greatest
closer to the coastline. For next week, rainfall totals in areas
south of US-59 are expected to range from 4-8 inches with isolated
higher amounts possible. Areas to the north will generally receive 2-
4 inches during this same period. This rainfall will likely result
in rises in rivers, streams and creeks. The heavy rainfall threat
currently looks to be greatest on late Thursday into Wednesday,
especially so if soils become saturated from prior rainfall and thus
more prone to runoff. Wet conditions look to continue through the
end of the week as a broad upper level low traverses through the
Gulf of Mexico.

Another component of uncertainty to this forecast will be an area of
low pressure, which is currently anticipated to develop over the
Southwestern Gulf of Mexico/Bay of Campeche during the first half of
the week. Currently this system is expected to track
west/northwesterly into Mexico late in the week. The fully impacts
of this potential tropical system remain relatively uncertain at
this time, in part due to uncertainties in the forecast track and
it`s northern extent. The heavy rainfall threat to SE Texas may
shift drastically depending on how this system evolves. Stay tuned
over the next several days as we monitor this possible system.

On a more minor note, a weak plume of Saharan Dust may pass overhead
early next week. NASA`s GMAO shows low optical thickness with this
plume of dust, so the impacts from this dust will likely be minimal.
This dust may create some hazy-white skies on Monday and Tuesday,
assuming there are some breaks in the cloud cover to see it in the
first place.

03

&&

.AVIATION...
(18Z TAF Issuance)
Issued at 1246 PM CDT Sat Jun 15 2024

VFR conditions will prevail for the current TAF period, with skies
remaining mostly clear through the remainder of the day and
overnight. SE winds will become light and variable overnight,
redeveloping tomorrow morning and remaining near or just below 10
knots. A few isolated showers/storms may develop tomorrow morning,
but (for now) coverage is expected to be low enough to justify
any wording in the current package. Looking ahead, an extended
period of unsettled weather is expected next week with frequent
thunderstorm activity.

Cady

&&

.MARINE...
Issued at 232 PM CDT Sat Jun 15 2024

Winds and seas will increase over the next several days as the
pressure gradient tightens while a long fetch sets up over the Gulf
of Mexico. Ample Gulf moisture will bring numerous showers/storms
daily, beginning on Sunday. Small Craft advisories will be needed
early next week as a coastal trough sets up near the Texas coastal,
bringing strong winds of 20 to 30 knots with gusts in excess of Gale-
Force possible. Seas are expected to reach 7 to 11 feet at times.
These strong onshore winds over a long fetch will also bring a high
risk of rip currents and potentially some coastal flooding across
the Texas coastline as early as Tuesday.

An area of low pressure is expected to develop over the Southwestern
Gulf of Mexico/Bay of Campeche by mid week. While this system is
currently expected to track west to northwesterly into Mexico later
in the week, there is much uncertainty. Forecasted winds and seas
may vary drastically depending on how this system evolves. Stay
tuned over the next several days as we monitor this possible system.

03

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)  72  94  75  92 /   0  10   0  30
Houston (IAH)  75  93  77  89 /   0  20  20  70
Galveston (GLS)  82  89  81  87 /   0  20  50  80

&&

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

$$

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