-- Discussion containing changed information from previous version are highlighted. --
826
FXUS64 KHGX 230412
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1112 PM CDT Sun Sep 22 2024

...New LONG TERM, AVIATION, MARINE, TROPICAL...

.SHORT TERM...
(This evening through Monday Night)
Issued at 250 PM CDT Sun Sep 22 2024

Hmm...the calendar says that it`s the first day of Fall, but when
I walk outside it still feels all summer-like. Why is it hot and
humid in Fall and where`s my FROPA?! The temperatures will
eventually simmer down a bit later this week due to a FROPA, but
that`s in the long term period. Here in the short term, we`re
still on the tail-end of influence from an upper level ridge.
That`s combined with onshore flow pulling in low-level moisture
and increased humidity from over the Gulf creating the hot and
humid conditions we`re all used to (and sick of at this point).
The main ridge axis will continue sliding off to the east as an
upper level trough drifts eastward from the Four Corners region
over to the Central Plains. This upper level trough has already
spurred the development of surface low pressure in W/NW Texas,
and as this low transitions northeastward it will drag a cold
front towards SE Texas. Now it won`t push through in the short
term forecast window though...so expect high temperatures in the
low to mid 90s both today and Monday.

As the front gets closer on Monday, it will lead to a surge in PW
values (1.6-2.0") as moisture converges along the frontal
boundary. As a result, we could see isolated to scattered showers
as early as Monday morning along the coast. Rain chances extend
further inland in the afternoon, but the higher end of the chances
generally remain near and south of I-10. Another impact from the
increase in low level moisture is patchy fog during the
overnight/early morning hours mainly for areas west of the I-45
corridor. Nighttime temperatures will remain above normal both
tonight and Monday night with lows in the low to mid 70s inland
and upper 70s closer to the coast. For portions of the Brazos
Valley, this does depend a bit on where the frontal boundary
stalls out at as some deterministic guidance has the front ever so
partially into SE Texas on late Monday night.

Batiste

&&

.LONG TERM...
-- Changed Discussion --
(Wednesday through next Sunday)
Issued at 1110 PM CDT Sun Sep 22 2024

Our pattern finally begins to change on Wednesday following a long
stretch of hot-and-humid weather as high pressure dominated over
Texas. An upper level trough digging down from the Northern Plains
will be entering the Lower Mississippi Valley on Wednesday, where it
will become a cutoff low and stall. PVA and moisture convergence
over coastal Texas will lead to increased showers and thunderstorms
activity on Wednesday (not just sea breeze activity), along with
increased cloud cover. The scattered showers and clouds will help
moderate daytime temperatures a bit, but WAA ahead of an approaching
cold front associated with the upper level low will lead to high
temperatures in the upper 80s to low 90s for much of the area. The
Piney Woods region may see the highest coverage of the afternoon
showers, so that are may not rise past the mid 80s. This
aforementioned cold front is expected to move through late Wednesday
into Thursday morning ushering in cooler, drier weather for Thursday.
Temperatures Wednesday night will be driven by the exact timing of
the FROPA, but we can expect low down into the mid to upper 60s for
much of the area, and then low 70s for the Houston Metro and along
the coast. Thursday is looking rather pleasant for our area with low
humidity and high temperatures generally in the mid 80s.

The upper level pattern gets a bit messy by the end of the week.
That closed low that stalls over the Mississippi Valley ends up
retrograding back westward Friday and into the weekend. This is due
to a tropical system (currently Invest 97L in the western Caribbean,
but likely a named tropical system by midweek) moving through the
eastern Gulf of Mexico effectively blocking the movement of the
upper level low. So, as this system moves back westward, so does the
moisture associated with it. The wrap around moisture may bring
scattered showers and storms to our area Friday into the weekend -
but confidence is not exactly high as it will be determined where
exactly the upper level low retrogrades to and how it interacts with
the tropical system. That upper level low ends up sticking around
through much of the weekend before finally moving off east late
Sunday into Monday. There will be a gradual increase in temperatures
Friday and through the weekend with highs back into the low to even
mid 90s by Sunday.

Fowler
-- End Changed Discussion --

&&

.AVIATION...
-- Changed Discussion --
(06Z TAF Issuance)
Issued at 1110 PM CDT Sun Sep 22 2024

VFR conditions will generally prevail through the 06Z TAF period. A
few areas of patchy fog, mainly between 09 and 15Z, may at times
result in sub-VFR visibilities for a brief period. Otherwise, winds
remain light and variable through the overnight period. Tomorrow, a
SE wind near 10 knots develops by late morning, with scattered
showers initially developing along the immediate coast and expanding
inland during the afternoon. With the latest models showing less
rainfall coverage than previously, have opted to continue to leave
out mentions of TSRA in this package. This potential will
nonetheless still need to be monitored. Winds again become light and
variable around 00Z.

Cady
-- End Changed Discussion --

&&

.MARINE...
-- Changed Discussion --
Issued at 1110 PM CDT Sun Sep 22 2024

Light to occasionally moderate onshore flow (5-10kt during the day,
then 10-15kt during the overnight and early morning hours) and low
seas (1-3ft) will continue through Tuesday. There will be increased
chances of scattered showers and isolated thunderstorms over the
coastal waters beginning through Tuesday as well. The winds
gradually back to the NE on Wednesday ahead of an approaching cold
front, and there will also be increased coverage of the showers and
storms on Wednesday. This cold front is expected to move through the
coastal waters late Wednesday night into Thursday bringing moderate
to strong northerly winds through Thursday night. Seas will likely
increase to 4 to 6 feet due to the increase in winds. Small Craft
Advisories may be needed.

Mariners should be advised that the NHC continues to monitor an area
of low pressure in the western Caribbean for tropical development
over the next several days. This system will gradually move
northwards and then northeastwards through the eastern Gulf of
Mexico through the end of the week. Little to no local impacts are
expected, but may see increased swells and increased risk of
strong rip currents by the end of the week.

Fowler
-- End Changed Discussion --

&&

.TROPICAL...
-- Changed Discussion --
Issued at 1110 PM CDT Sun Sep 22 2024

The National Hurricane Center (NHC) has now designated the area of
low pressure in the western Caribbean as Invest 97L. Gradual
development of this system is expected over the next few days with a
Medium (50%) chance of development into a named tropical cyclone
within 2 days, and a High (80%) chance within the next 7 days. It is
expected to generally move northward across the eastern Gulf of
Mexico through the end of the week, and interests along the
northern and northeastern Gulf of Mexico should closely monitor the
forecast as conditions are favorable for development. Little to no
impacts are expected locally for SE Texas, but there will likely be
increased risk of strong rip currents by the second half of this
week. Please continue to monitor the latest forecasts and updates
from the NHC at www.hurricanes.gov.

Fowler
-- End Changed Discussion --

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)  74  93  74  92 /   0  10  10  30
Houston (IAH)  76  93  76  93 /   0  20  10  50
Galveston (GLS)  80  87  79  87 /  20  30  10  40

&&

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

$$

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