352
FXUS64 KHGX 201138
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
638 AM CDT Sat Jul 20 2024

...New AVIATION...

.SHORT TERM...
(Today through Sunday Night)
Issued at 408 AM CDT Sat Jul 20 2024

Slow moving showers and thunderstorms have been developing and
affecting locations near and south of I-10 early this morning.
Models are not handling this activity well and it has been fairly
impressive how strong they have been over the past few hours. Some
storms produced rainfall amounts of 2-3 inches per hour, leading to
several flood advisories and a flash flood warning over portions of
Galveston and Brazoria counties. Although we are expecting for most
of this activity to ebb during the next few hours, some storms could
remain in the area. The HRRR shows the storms moving south into the
local waters by sunrise with little activity flaring up in the
afternoon and evening. However, the ARW/RAP13/FV3 still show storms
firing up over areas south of I-10 in the morning and then expanding
a little more inland in the afternoon and evening.

Today, we have the lingering frontal boundary just north of the
coastal area with warm and moist airmass along and south of it and
CAPE values around 2500 J/kg. A vort max could also move over the
coastal zones later. For those north of I-10, conditions may not be
as good for storm development and some of these areas may also be
fighting with a bit of a cap. Thus, I was in favor with keeping
isolated to scattered showers and thunderstorms today mainly for the
areas near and south of I-10 (especially if the boundary doesn`t move
south) and isolated activity to the north. With the stronger storms,
rainfall rates of 2-3 inches per hour are possible on occasion and
could lead to minor flooding over urban and poor drainage areas, as
well as ponding of water on roadways. Now, if the boundary does move
southward today, then rain chances will be much less inland.

For tonight, skies will be mostly clear for the Brazos Valley and
Piney Woods region with lows in the low to mid 70s. South of this,
skies will be partly cloudy with lows in the mid to upper 70s.
Slight chances for showers mainly over areas around Galveston Bay.
Rain chances will be on the rise on Sunday as the boundary moves
northward and the warm moist air from the Gulf pushes further
inland. The higher PoPs are once again situated over areas near and
south of I-10. Rainfall rates of 2-3 inches per hour at times isn`t
out of the question again for this region, therefore, the threat of
minor flooding could continue - especially for locations that
receive good amounts of rainfall today.

Although conditions improve Sunday night, the stormy weather pattern
is to continue for the next few days. Please continue to monitor the
latest forecast and have multiple ways of receiving weather alerts.

Cotto (24)

&&

.LONG TERM...
(Monday through Friday)
Issued at 408 AM CDT Sat Jul 20 2024

The long term discussion is beginning to sound like a broken record,
but there is only so many ways to say that next week is gonna be
rainy. A combination of high PWATS (around 2.2-2.4") and a stalled
upper level disturbance over the Central and Southern Plains will
lead to showers and thunderstorms each day through the long term.
While the entire area will likely see at least scattered storms
Monday and Tuesday, areas north of Harris County appear to have a
better set up for more widespread storms thanks to being closer to
the upper level low. This disturbance is looking to meander a bit
further south Wednesday through Friday leading to increased chances
of widespread rainfall across the entire region. Rainfall totals
through the week will generally be up to 3 to 5", but isolated
higher amounts will be possible. WPC has placed the northern third
of the region in a Slight Risk (level 2 of 4) for Excessive Rainfall
and the rest of the region in a Marginal Risk (level 1 of 4) for
both Monday and Tuesday of next week. Then the entire region will be
under the Slight Risk on Wednesday. Not only do the dynamics for
widespread heavy rainfall look better beginning Wednesday, but
saturated soils from the previous few days of rainfall will lead to
higher chances of flooding.

The flip side of the overcast skies and rainfall is that daytime
temperatures will be running around 5 to 10 degrees below normal all
week long, only getting into the mid to upper 80s through the week.
The overnight lows will be near to slightly above normal, in the mid
to upper 70s, thanks to the overcast skies keeping the ground well
insulated.

Fowler

&&

.AVIATION...
(12Z TAF Issuance)
Issued at 623 AM CDT Sat Jul 20 2024

VFR conditions and light VRB winds expected for much of the TAF
period. Iso-sct SH/TS possible today, mainly for areas near and S
of I-10, as a weak frontal boundary meanders across SE TX.
Tranquil conditions expected tonight for inland portions. Winds
become S-SE Sunday as the boundary lifts northward.

Cotto (24)

&&

.MARINE...
Issued at 408 AM CDT Sat Jul 20 2024

A stalled boundary near the coast will bring continued chances of
showers and thunderstorms through the weekend. Gusty winds and heavy
rainfall will be possible with any stronger storms that develop.
Rain chances will persist through next week as well. Otherwise,
light onshore flow and sea around 1 to 3 feet will prevail through
at least mid week next week.

Fowler

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)  93  74  94  75 /  10  10  20  10
Houston (IAH)  92  76  92  77 /  40  20  70  30
Galveston (GLS)  89  80  89  80 /  40  40  80  50

&&

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

$$

SHORT TERM...Cotto
LONG TERM....Fowler
AVIATION...Cotto (24)
MARINE...Fowler