Area Forecast Discussion
Issued by NWS Houston/Galveston, TX

Home |  Current Version |  Previous Version |  Graphics & Text |  Print | Product List |  Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45
601
FXUS64 KHGX 111729
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1229 PM CDT Thu Jul 11 2024

...New AVIATION...

.SHORT TERM...
(Today through Friday Night)
Issued at 309 AM CDT Thu Jul 11 2024

The current synoptic pattern, largely characterized by a mild but
steady onshore flow and daily rainfall chances driven mainly by
diurnal heating, will prevail through the remainder of the week. A
slight retrograde of the prevailing surface high offshore of the
Eastern Seaboard will promote a more uniform southeast wind, though
an overall weak pressure gradient will keep wind speeds light.
Meanwhile, a weak but nonetheless present stationary boundary will
remain situated just offshore, enhancing the potential for diurnally
driven showers and storms this afternoon.
Have maintained PoP values in the 40-60% range this afternoon for
areas along and south of the I-10 corridor, with expected storm
coverage looking to be similar to that of yesterday. High
temperatures, while remaining near seasonal normal values (low to
mid 90s), will nonetheless aggravate the risk for heat-related
illnesses due to the ongoing widespread power outages across Greater
Houston. With heat index values again rising into the triple digits,
a Heat Advisory has once again been issued in consideration of the
post-storm conditions. If planning any outdoor work today, remain
aware of the signs of heat related illnesses, stay hydrated, plan
work to avoid the hottest parts of the day, and use municipal
cooling centers if available.

Friday is shaping up to be a similar day to today, with rainfall
chances concentrated along the immediate coast and highs generally
in the lower 90s. Another Heat Advisory may be needed depending on
the ongoing power outage situation. For both tonight and tomorrow
night, expect lows to sit in the upper 70s to around 80.

Cady

&&

.LONG TERM...
(Saturday through Wednesday)
Issued at 309 AM CDT Thu Jul 11 2024

The overall long term period can be summarized by saying there will
be a chance for showers and storms nearly every day along with a
gradual warming trend...but y`all are stuck with me on the forecast
desk so we`re gonna take a deeper dive and discuss exactly why
that is. Let`s get started! We pick things up on Saturday, which
is when we have the highest rain chances for the forecast period.
Lingering deeper moisture (PW values greater than 2.0") continues
to sit over Southeast TX along with PVA from a nearby upper level
inverted trough. Combine that with daytime heating and sea
breeze/outflow boundary interactions and we should see some decent
coverage of afternoon showers and storms. Daytime temperatures on
Saturday start out in the low 90s...and it doesn`t get any
"cooler" than that going forward.

On Saturday night, upper level high pressure over the southeastern
CONUS expands westward and increases 500mb heights over Southeast TX
to around 594-596 dam. This does grant us a degree or two bump in
our high temperatures on Sunday and Monday, but it also
significantly drops rain chances due to the increased subsidence
aloft. We`ll go from rain chances peaking around 60% on Saturday
down to 30% on Sunday and less than 10% on Monday (sad stonks).
Things get a little bit interesting on Monday as the previously
mentioned upper level inverted trough drifts into the TX panhandle
and evolves into an embedded upper level low. The main implications
from this is decreasing our 500mb heights a bit which brings back
our typical summertime pattern of shower/storms developing along the
seabreeze in the afternoon and dissipating after sunset beginning
again on Tuesday. So, locations near and south of I-10 will have the
best chances of seeing rainfall through midweek. While we were
talking about rain chances, that warming trend kept on truckin`
along and now we`re looking at high temperatures in the mid to upper
90s by midweek. Some portions of the Brazos Valley may even flirt
with the 100F mark. It`s a verrry early look, but we`ll have to
monitor heat index values around midweek as they look to at least
approach the Heat Advisory threshold ( 108F).

Batiste

&&

.AVIATION...
(18Z TAF Issuance)
Issued at 1223 PM CDT Thu Jul 11 2024

SHRA/TSRA developing along the sea breeze boundary in our coastal
counties should push northward this afternoon. Right now we show
VCTS as far north as CXO. Models disagree regarding how far north
TC activity will extend before the loss of daytime heating weakens
the storms. SHRA/TSRA possible again tomorrow, especially from IAH
south to the coast. Chance of rain increases in the morning. But
uncertainty exists regarding SHRA/TSRA coverage. For now, we opted
for VCSH in the TAFs tomorrow. Winds should remains light with
mostly VFR cigs/vis. The exception will be in locations
experiencing a thunderstorm. Patchy fog cannot be ruled out
tonight in areas that receive rainfall. However, confidence is low
regarding patchy fog development.

&&

.MARINE...
Issued at 309 AM CDT Thu Jul 11 2024

Overall a relatively benign period of marine conditions continues
with light to occasionally moderate onshore flow and 2-3 foot seas
persisting into early next week. Most days throughout the forecast
period will feature a chance for isolated to scattered showers and
thunderstorms (especially on Saturday), and mariners can expect
locally higher winds and seas near and within any thunderstorms.

Batiste

&&

.HYDROLOGY...
Issued at 309 AM CDT Thu Jul 11 2024

As of early Thursday morning, there are three Flood Warnings in
effect following the heavy rainfall and subsequent runoff from
Hurricane Beryl. The Tres Palacios River at Midfield crested in
major stage on Tuesday and is continuing to recede...it is forecast
to fall below flood stage by early Friday morning. The San Bernard
River at Boling crested in minor flood stage Tuesday and has fallen
back into action stage, but it is expected to have a secondary crest
into minor flood stage this afternoon. Lastly, Cypress Creek at
Sharp Road in western Harris County remains above flood stage and it
may take a day or so to recede.

There are a couple more sites that may need Flood Warnings at some
point over the next few days. The East Fork of the San Jacinto River
at New Caney is expected to crest into minor flood stage late this
evening and into the weekend. The Trinity River at Moss Bluff is
forecast to barely crest into minor flood stage over the weekend.

The excessive rainfall from Beryl along with subsequent unrelated
rounds of rainfall have left portions of Matagorda, Brazoria, Fort
Bend, Galveston, and Harris counties with above normal soil
moisture. With rain chances remaining elevated (~40+%) through
Saturday, it`s important to note that additional rainfall in these
areas will turn into runoff quickly.

Remember to heed any instructions from your local officials and to
NEVER travel through ANY flooded areas or roadways. TURN AROUND,
DON`T DROWN. Please monitor updated forecasts via the NWS NWPS
webpage (https://water.noaa.gov/).

Batiste

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)  74  93  74  94 /  10  30   0  30
Houston (IAH)  76  91  76  93 /  30  60  10  50
Galveston (GLS)  81  88  81  89 /  50  50  20  40

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...Heat Advisory until 8 PM CDT this evening for TXZ163-164-176>179-
     195>200-210>214-226-227-235>238-300-313-335>338-436>439.

     High Rip Current Risk until 10 PM CDT this evening for
     TXZ436>439.

GM...None.
&&

$$

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