Damaging Winds in Texas, August 24, 2023

Area Forecast Discussion
National Weather Service Houston/Galveston TX
348 PM CDT Thu Aug 24 2023

...New SHORT TERM, LONG TERM, MARINE, FIRE WEATHER...

.SHORT TERM...
(This evening through Friday Night)
Issued at 338 PM CDT Thu Aug 24 2023

Today is National Weather Complaint Day and ohhhhh my goodness
gracious do I have some complaints! Firstly, did you know that today
is our 26th consecutive day with heat alerts in effect for at least
some part of Southeast Texas?! We already have heat alerts locked in
for Friday as well, which will make it 27 days in a row...almost two
full fortnights! I know it's usually hot in the summer, but this
year has been flatout ridiculous! By 12pm today, both Galveston and
Houston-Hobby Airport had already broken their daily maximum
temperature records and College Station was at 104°F. I don't even
want to look at my electricity bill these days...but the good news
is that a few of you may get a brief reprieve from the outrageously
hot temperatures in the form of rain! The bad news is that most of
you won't get any rain...may the odds be ever in your favor.

The midlevel high has retreated just northwestward enough to allow a
shortwave embedded in the flow aloft to drift through. That combined
with a weak surface trough moving in (explains the light and
variable winds that are allowing us to bake) along with PW values
ranging from 1.6"-1.9" means that we have the potential for isolated
to widely scattered convection to develop this afternoon. The high-
res models are more onboard with this than the global models for
today...and vice versa for Friday. Anything that does develop will
need to be monitored for gusty wind potential with very steep sfc-
3km lapse rates (~10°C/km), DCAPE greater than 1500 J/kg, and dry
air extending from the surface to about 2.5 km (inverted-V
sounding). Expect any convection that develops to dissipate shortly
after sunset. Based on today's temperatures, sunset can't come soon
enough. As of 2pm, we are seeing widespread values of 100+°F
temperatures at pretty much all of our sites except for coastal
locations...and even then Galveston was sitting at 98°F. Heat index
values are subsequently elevated with values ranging from 107-114°F.
As a result, Excessive Heat Warnings and Heat Advisories remain in
effect.

By Friday, the midlevel high will be a bit further to the north so
it won't be as hot as it is today...but still fairly hot.
Temperatures will top out in the 101-106°F range with heat index
values in the 107-113°F range. As a result, another round of
Excessive Heat Warnings/Heat Advisories will be in effect for Friday
with the dividing line between the two generally being the I-10
corridor. A similar setup is in place as far as another shortwave
wrapping around the midlevel high, but confidence for rain is
generally higher the further north you go. This is because some
models are indicating a pocket of drier air (PW values < 1.4")
sliding in from the east along the coast around the time convection
begins developing. PoPs are generally in the 20-30% range with
higher values up north towards the Brazos Valley/Piney Woods. This
will not be anywhere near enough to even put a dent into recovering
from the ongoing drought. In case you haven't seen today's drought
monitor update, all of Southeast Texas is now AT LEAST in an extreme
drought (D3). Far eastern locations and portions of Matagorda County
are in an exceptional drought (D4), which is as high as it can go.
Rain is badly needed here, and we're going to complain until we get
it!

Batiste

&&

.LONG TERM...
(Saturday through next Wednesday)
Issued at 338 PM CDT Thu Aug 24 2023

This weekend, the mid to upper level ridge over the TX/OK
Panhandle should drift westward towards the southwestern CONUS.
Weaker influence from the ridge should provide slight relief from
the heat, though 850mb temperatures upwards of 22-25C should still
bring widespread highs in excess of 100 degrees (outside of the
immediate coast). Weak capping and reduced subsidence will provide
a slight chance of isolated storms over the weekend, especially
with help from afternoon heating and other mesoscale processes
(i.e. the sea/bay breeze).

Heading into next week, an upper level trough axis over the Great
Lakes should deepen, pushing a weak frontal boundary across the
Plains on Monday. Moisture should pool ahead of this boundary as
PWs near 1.8-2.1 inches across the region. This will coincide
with the arrival of weak impulses passing overhead, bringing
higher rain chances for Monday. However, temperatures should
still be especially hot in areas that don't receive rainfall. The
weak frontal boundary is progged to reach SE Texas on Tuesday,
later stalling and becoming quasi-stationary along the coastline
on Wednesday. Interactions between this boundary and the sea/bay
breeze will further enhance storm development, putting our highest
rain chances in for Tuesday afternoon. Increased cloud cover,
reduced 850mb temperatures and northerly flow ushered in by this
boundary should bring more substantial relief from the heat, with
highs dropping into the upper 90s to lower 100s. This is still
contingent on the front making it to SE Texas. Should the front
stall further north than currently expected, relief from the heat
may be greatly limited.

03

&&

.AVIATION...
(18Z TAF Issuance)
Issued at 1140 AM CDT Thu Aug 24 2023

Winds will remain relatively light and variable over the next few
hours as a weak surface boundary pushes through the area. Expect
winds to become southeasterly and gradually increase from the
coast northward as the sea breeze rolls in. High resolution model
guidance continues to point towards scattered convection
developing between 20Z-02Z from north to south. Confidence of
development is higher the further north you go, so VCSH has been
included for HOU/SGR and northward. Any convection that develops
will dissipate shortly after sunset. Winds trend towards becoming
light and variable overnight and will be predominantly
southeasterly on Friday. Another round of isolated to scattered
showers/storms will be possible Friday afternoon.

Batiste

&&

.MARINE...
Issued at 338 PM CDT Thu Aug 24 2023

Light to moderate, sea and land breeze driven winds are expected
over the next several days, with sea of 1 to 3 feet. Rain chances
increase on Monday as a weak frontal boundary approaches the area.

03

&&

.FIRE WEATHER...
Issued at 338 PM CDT Thu Aug 24 2023

Although winds are light today due to a weak surface boundary moving
into the area, minimum relative humidity values are still fairly low
to go along with critically to extremely dry fuels and excessive
heat. As a result, fire weather conditions will continue to remain
elevated over the next few days. Relative humidity values this
afternoon will mainly range from 20-30% and increase to 30-40% for
Friday afternoon. Winds will remain light today, but will be a bit
higher out of the southeast on Friday around 10-15 mph. Regardless
of a Red Flag not being out, extreme caution should still be taken
if working outdoors with any flammable materials. Please keep in
mind that all of the counties in Southeast Texas are under a burn
ban, so be sure to follow your local ordinances. Forecast fire
danger from the Texas A&M Forest Service remains high to very high
for areas north of I-10 over the next few days, and all of Southeast
Texas is now in at least an extreme drought.

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)	  81 105  77 104 /  20  30  20  10
Houston (IAH)			  81 103  80 104 /  20  20  10  20
Galveston (GLS)			  83  92  82  92 /  20  20  10  20

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...Excessive Heat Warning until 9 PM CDT Friday for TXZ163-164-
     176>179-195>200-210>212.

     Excessive Heat Warning until 10 PM CDT this evening for TXZ213-
     227-300.

     Heat Advisory from 10 PM this evening to 9 PM CDT Friday for
     TXZ213-227-300.

     Heat Advisory until 9 PM CDT Friday for TXZ214-226-235>238-313-
     335>338-436>439.

GM...None.
&&

SHORT TERM...Batiste
LONG TERM....03
AVIATION...Batiste
MARINE...03
FIRE WEATHER...Batiste