690
FXUS64 KHGX 091749
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1249 PM CDT Fri Aug 9 2024

...New AVIATION...

.SHORT TERM...
(Today through Saturday Night)
Issued at 257 AM CDT Fri Aug 9 2024

The Heat Miser`s grasp on Southeast Texas continues with yet another
day of above normal temperatures. That`ll be in spite of a frontal
boundary backing in from the northeast later this morning and
lingering around the I-45 corridor throughout the day. This`ll be a
key factor into our rain chances this afternoon, but heat is the
most important impact so let`s discuss that first. With upper level
high pressure remaining overhead along with 850mb temperatures in
the 99th to MAX percentiles, surface temperatures this afternoon
will be able to reach the upper 90s to low 100s. Moisture
convergence along the frontal boundary will increase PW values up to
1.9-2.2", especially along and west of I-45. Above normal heat and
elevated moisture isn`t exactly a good combination as it results in
elevated heat indices. It`s not too surprising that a Heat Advisory
is in effect for all of Southeast Texas through this evening with
heat indices between 108-112F being possible. Now let`s discuss
what all of this daytime heating means for rain chances in the
afternoon.

With PW values reaching the 75th to 90th percentile this afternoon
along with a lingering frontal boundary/sea breeze, some fairly
decent daytime heating should be able to allow some convection to
break through the cap for isolated to widely scattered
showers/storms to develop. This mainly looks to occur south of I-10
and west of I-45. While this is going on, another frontal boundary
will be gradually drifting southward through North Texas. The 00Z
CAMs are in fairly good agreement on a cluster of storms forming
along then racing ahead of this frontal boundary as it tracks
southward into the Brazos Valley in the late afternoon to early
evening hours. While shear is essentially non-existent, moderate
instability and steep low-level lapse rates will be enough to
support some isolated strong wind gusts in the strongest storms. As
a result, SPC has outlined a marginal risk of severe weather (level
1 out of 5) for portions of the Brazos Valley today.

The frontal boundary will still be lingering around Southeast Texas
on Saturday. Although the moisture will be lower and the capping
will be a bit stronger, there still looks to be enough support
between the lingering boundary and daytime heating to kick off some
isolated convection mainly south of I-10 and west of I-45 in the
afternoon. 850mb temperatures will be ever so slightly lower, which
translates to surface temperatures being ever so slightly lower by
about a degree or so compared to Friday. Heat indices will be more
borderline for a Heat Advisory on Saturday, but areas west of I-45
would be the most likely to see another issuance if need be. Low
temperatures on both nights will mainly be in the upper 70s to low
80s, so there won`t be much relief from the heat overnight.

With heat indices around or above Heat Advisory criteria ( 108F),
please continue to keep heat safety at the forefront of any plans
that you make (especially if outdoors). Know the signs of heat
related illnesses (heat stroke/heat exhaustion), drink plenty of
water to stay hydrated, take frequent breaks from the heat, avoid
strenuous outdoor activities during the hottest part of the day,
wear sunscreen and loose/light-colored clothing, and ALWAYS ALWAYS
ALWAYS LOOK before you LOCK your vehicle. Don`t forget about your
pets as well! If the ground is too hot for the palm of your hand,
then it is too hot for their paws.

Batiste

&&

.LONG TERM...
(Sunday through Thursday)
Issued at 257 AM CDT Fri Aug 9 2024

Mid/upper level ridging remains in place and helps to bring above normal
temperatures to a majority of the area. A mainly light onshore flow
persists as the area resides on the west side of a Gulf of Mexico surface
high. High temperatures each day will be in the mid to upper 90s with
a few locations possibly reaching 100 degrees. Heat index values do
not peak until the Tuesday through Thursday time period when 108-112
readings are expected and a Heat Advisory will probably be needed. Even
if there is no Advisory in effect, continue to take all heat precautions.
Subtle weaknesses in the ridge could allow for some rain to edge back
into the forecast starting on Monday, mainly in the morning near the
coast and inland in the afternoon with the inland extent generally in/
around the Highway 59/69 corridor. 42

&&

.AVIATION...
(18Z TAF Issuance)
Issued at 1230 PM CDT Fri Aug 9 2024

For the most part, VFR conditions are expected through the forecast
period, but there could be some issues later this afternoon for NW/
W portions of the CWA. A weak almost stationary surface front along
with jet streak activity aloft could produce some isolated showers/
storms generally along and west of a line from Madisonville to Ang-
leton from 21Z-02Z if near-term models verify. There has not been a
whole lot of run-to-run consistency with these rain chances, so go-
ing to opt to only keep VCSH in for CLL mention at this time. Winds
will remain light NE (3-8kts) during the daytime hours...lighter to
calm and variable overnight. 41

&&

.MARINE...
Issued at 257 AM CDT Fri Aug 9 2024

Light winds and low seas will prevail. During the overnight hours, winds
may intermittently increase to around 10 to 15 knots. Rain chances remain
low.  42

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)  99  78  99  77 /  20  20  10   0
Houston (IAH) 100  80  99  79 /  10  20  10   0
Galveston (GLS)  93  83  93  82 /  10  10  10   0

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...Heat Advisory until 9 PM CDT this evening for TXZ163-164-176>179-
     195>200-210>214-226-227-235>238-300-313-335>338-436>439.

GM...None.
&&

$$

SHORT TERM...Batiste
LONG TERM....42
AVIATION...41
MARINE...42