-- Discussion containing changed information from previous version are highlighted. --
929
FXUS64 KHGX 290854
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
354 AM CDT Wed May 29 2024

...New SHORT TERM, LONG TERM, MARINE...

.SHORT TERM...
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(Today through Thursday Night)
Issued at 342 AM CDT Wed May 29 2024

We have gotten out of the hot and humid pattern (for now) and into a
pattern of active weather during the afternoon/evening periods. This
pattern is expected to continue today and Thursday as more MCS
structures impact SE Texas.

We have an area of showers continuing to work their way through the
area this morning...at this point the atmosphere may be pretty
worked over, so thinking after these showers exit the area, we
should be fairly quiet through the morning. Another round of showers
and thunderstorms may initiate along the sea breeze this afternoon.
Later in the day, going into the nighttime hours, another MCS is
projected to sag SE from the Dallas/Fort Worth area. Hi-res models
continue to be pretty spread on timing and strength of the next
system. The pattern has been that the Hi-Res models have been
underdoing any activity and have been late on timing...So, that
being said, I want to point out a few things...

There are three necessary ingredients for thunderstorms to form.
Moisture is one of those ingredients, and looking at today and
Thursday, PWAT values are in the 1.5-2.0" range with a pretty deep
moisture column. So we have that available...

Next, we need instability... That is certainly available. CAPE
values once again will be in excess of 4000 J/kg towards western
counties with 3000-4000 J/kg elsewhere. The capped layer appears to
break down with daytime heating, so once that erodes, all of that
energy will become available. Lifted Index values suggest a highly
unstable environment over the entirety of SE Texas. Lapse rates
aren`t as steep in the mid-levels as what was observed yesterday,
which suggests a pretty marginal hail threat. DCAPE values are
hovering around 1000 J/kg (anything above 1000 J/kg suggests an
increased potential for severe winds).

Lastly, we need a source of lift. We have a few ripples of energy
within the synoptic flow in the 500mb layer as well as a shortwave
in the 700mb layer today and Thursday. These along with the
afternoon seabreeze may provide enough lift to get storms going.

SPC has a Marginal Risk (level 1 of 5) in place for the entire area
today and a portion of SE TX for Thursday(generally north of I-10
and west of I-45). Damaging wind and large hail would be the main
threats with storms.

WPC also has the area in a marginal risk for excessive rainfall
through the short-term period. Some storms could produce heavier
downpours, which may contribute to street flooding or flooding in
low-lying and urban areas.

The good news is that the combination of rain, cloudy skies, and
lower 850mb temperatures will lead to a lesser heat threat. Highs
for today and Thursday will be in the 80s area wide. A few locations
closer to the metro may touch 90 degrees. Lows will be on the warmer
more humid side as cloud cover acts as an insulator and traps the
daytime heating. Temperatures tonight and Thursday night will be in
the 70s.

Adams
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&&

.LONG TERM...
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(Friday through Tuesday)
Issued at 342 AM CDT Wed May 29 2024

There will not be much of a pattern change in the long term, so
expect continued chances for showers and thunderstorm pretty much
each day. High moisture content will remain in place thanks to the
onshore flow with PWATs remaining near 1.5-2". There will be passing
upper-level shortwaves almost each day (sometimes more than once per
day) through early next week. The first one will be moving through
Friday morning/afternoon bringing with it showers and storms. This
shortwave may pass just to the north, meaning that the Pineywoods
would likely have the best chance for seeing the storm activity.
Then the next shortwave moves in pretty shortly thereafter, sometime
Friday evening into Saturday morning. And this one is looking to
track a bit further south, bringing the shower and storm activity
across much of the area. Conditions are looking favorable for
isolated strong to maybe severe thunderstorms on Friday, so the
SPC has placed most of SE Texas in a Slight Risk (level 2 of 5)
in their Severe Weather outlook for Friday. Similarly, WPC has SE
Texas in a Marginal (level 1 of 4) to Slight Risk (level 2 of 4)
for Excessive Rainfall on Friday as those high PWATs will mean
that locally heavy rainfall would be possible. Looking like we
will get a break from the activity during the day on Saturday, but
the next shortwave moves in Sunday morning bringing again a
chance of showers and storms. Weak riding looks to build in late
Sunday through Monday giving us a reprieve from the storms, but
another disturbance looks to arrive on Tuesday.

All these systems moving through will provide us with a bit of a
reprieve from the extreme heat. High temperatures Friday and
Saturday will generally be in the mid to upper 80s. A gradual warm
up is expected Sunday through Tuesday with highs rising into the low
90s. Overnight lows will be well above normal through the long term
with minimum temperatures in the mid to upper 70s are expected.

Fowler
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.AVIATION...
(06Z TAF Issuance)
Issued at 1221 AM CDT Wed May 29 2024

GLS at MVFR with CIGs. All other sites at VFR. Have some light to
moderate rain moving into the area from the west over the next
couple of hours, likely affecting terminals along and south of
IAH. Still seeing some lightning strikes within this cluster of
storms, but winds have weakened substantially. Gusts to 25 kts
will still be possible overnight as this system moves through.
MVFR CIGs may develop overnight, with improvement to VFR expected
by 14-17Z. Another round of scattered SHRA/TSRA expected during
the late afternoon into early evening hours. A repeat of MVFR CIGs
Wednesday night into Thursday morning is expected. Thursday will
also feature another shot at storms.

&&

.MARINE...
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Issued at 342 AM CDT Wed May 29 2024

Light to occasionally moderate onshore flow will persist into
next week with seas around 3 to 5ft. Small craft may need to
exercise caution through this morning as the onshore flow peaks at
around 15kt with gusts to 20kt possible. Additional periods of
cautions may be needed at times through the remainder of the week,
especially during the overnight periods. Showers and
thunderstorms will be possible this morning and this afternoon,
with additional chances possible through the start of next week.
The persistent onshore flow will also lead to a high risk of
strong rip currents through the weekend.

Fowler
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&&

.HYDROLOGY...
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Issued at 426 PM CDT Tue May 28 2024

There are currently three River Flood Warnings in effect: two along
the Trinity River and one on the Navasota River. The Trinity River
at Liberty is currently in moderate flood stage through Tuesday
night, then drops out of minor flood stage later this week. The
Trinity River at Moss Bluff will remain in minor flood stage until
further notice. The Navasota River at Normangee has reached its
crest in minor flood stage and is forecast to drop below flood stage
later this week.

Please monitor updated forecasts via the NWS AHPS
website and/or the new NWS NWPS webpage (https://water.noaa.gov/)
as the river flood threat persists.

Batiste
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&&

.PRELIMINARY POINT TEMPS/POPS...
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College Station (CLL)  87  74  87  73 /  60  30  50  20
Houston (IAH)  87  76  87  75 /  60  30  60  10
Galveston (GLS)  85  79  86  79 /  60  30  50  10
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&&

.HGX WATCHES/WARNINGS/ADVISORIES...
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TX...Wind Advisory until 7 AM CDT this morning for TXZ195-197-210-211.

GM...Small Craft Should Exercise Caution until 11 AM CDT this morning
     for GMZ330-335-350-355-370-375.
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&&

$$

SHORT TERM...Adams
LONG TERM....Fowler
AVIATION...Adams
MARINE...Fowler