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642
FXUS64 KHGX 242119
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
419 PM CDT Fri May 24 2024

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

.SYNOPSIS...
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Issued at 257 PM CDT Fri May 24 2024

Hey, it`s summer now...Longhorn out front shoulda told ya. To
commemorate the traditional beginning of summer, the atmosphere is
gifting us with conditions that would be right at home or even on
the warm side in July or August, much less Memorial Day. We`ll
also be doing our near-daily check to see if any late
afternoon/evening storms make their way into the area. Tonight
looks to have some promise as storms now initiating over North
Texas may grow strong enough to survive into northern portions of
the area. But I`m also eyeing next week, as a northwest flow
pattern aloft gets set up.

Speaking of the heat, even though the numbers aren`t too eye-
popping on an absolute scale, they are are definitely on the warm
side for this early in the summer. Early season heat can be sneaky
in that impacts to unacclimated bodies can start being problematic
at lower levels, so working to keep yourself cool early in the
summer, with heat typical of deeper in the season, and during a
holiday weekend with lots of outdoor activities is a wise plan.
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&&

.SHORT TERM...
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(This evening through Saturday Night)
Issued at 257 PM CDT Fri May 24 2024

Today begins the holiday weekend for most (some of us get to be
here working all weekend!), and we`re already getting an initial
taste of hotter conditions. Most obs around the area are reporting
heat index values in the 102-105 range thanks to temps in the
lower 90s and dewpoints in the upper 70s. Isolated spots - hey
there, Katy at 108 - are even higher on the scale.

Going into tonight, those high dewpoints are going to be key for
the overnight forecast. The closer you get to the coast and the
source of this deep, Gulf moisture, the harder we have been
finding it to drop below 80 degrees, and that is not going to
change for at least the next couple of nights.

For those in the northern part of our area - Bryan/College
Station, Madisonville, Crockett...basically those living north of
the big Sam Houston statue, you`ve also got to keep an eye on
those storms getting going in North Texas this afternoon. These
storms will be gradually heading your way. The environment over
most of Southeast Texas isn`t very supportive of storms, but for
those folks up north, there could be just enough for some isolated
strong/severe, but weakening, storms to cause a bit of trouble
tonight before dying out.

Tomorrow slides us up a bit more as far as the heat goes. It won`t
be "too hot", in the sense that 850 mb temperatures are "only"
exceeding the 97.5th percentile in both the NAEFS and Euro
ensemble means. Yeah...I`m looking at my high temp map and
dewpoints, and this just looks like the dog days of summer to me,
not late May. One...nice...thing about Saturday is that the depth
of moisture may not be as great, allowing for some modestly drier
air to mix down in the afternoon. This won`t do a whole lot, with
dewpoints only forecast to get into the lower 70s but it`s better
than nothing. Combine that humidity with temperatures inching up
more towards the middle 90s, and inland heat index values look to
peak out in the 105-107 degree range, with triple digit peaks all
the way to the Gulf.
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&&

.LONG TERM...
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(Sunday through next Thursday)
Issued at 257 PM CDT Fri May 24 2024

The unseasonable heat persists all the way through the holiday
weekend. Ensemble mean 850 temps remain above the 97.5th
percentile, and look more like exceeding the 99th percentile, and
may even threaten the high end of the model climatology. The Euro
ensemble`s Extreme Forecast Index shows Sunday similar to
Saturday, in that a portion of the area is showing a signal for
extreme heat...exceeding 0.5. On Monday, it turns that dial up
some more, with most all of the area above 0.6, and in some
locations going as high as the 0.8 to 0.9 range, indicating high
confidence in that high-end heat. Let`s not discuss the EFI for
overnight lows, which indicates an even stronger signal for high-
end values. If you`ve been outside late at night or just before
dawn in recent evenings...you already know, and it`s not going to
get any better.

There are a few different ways we can try to put this weekend`s
heat into context. One is the traditional heat index, which
considers temperature and humidity, and assumes a shaded location
and ignores wind. This is probably pretty useful if you plan on
being outside, but generally shaded from the sun and wind, and
don`t plan on being particularly active. The 105-107 peak values
on Saturday look similar on Sunday, but nudging upward slightly
into a 106-109 range. This is high enough that if the forecast
holds, we would need to consider heat advisories. As the previous
paragraph hints at, Monday ups the ante even more, as my peak heat
index forecast values push up to around 110 degrees. This is
partly from high temperatures, but also appears to be aggravated
by deepening moisture, keeping afternoon dewpoints from mixing
down as much as I mentioned above for Saturday.

There are a couple other ways to look at heat impacts as well. One
is an experimental product known as HeatRisk, making its way over
from NWS offices in the West. This is particularly useful in
putting the forecast temperatures in a historical context, as it
puts the forecast into risk categories based on high and low
temperatures compared to climatology. For Saturday, Sunday, and
Monday, the bulk of the area falls into the Red/Major (level 3 of
4) category. This highlights that while the numbers we`re
discussing "sound" normal compared to the entirety of summer
around here, it`s actually quite hot relative to what we typically
see around Memorial Day.

Finally, there is the Wet Bulb Globe Temperature that we can also
look at. If you are a veteran, distance runner, and/or competitive
marching band person, there`s a good chance you`re already
familiar with this index! For those unfamiliar, it is a complex
index that takes into account temperature, humidity, wind, and the
intensity of the sun`s rays. This makes it useful for those who
are particularly active outdoors and more exposed to the elements.
This index is also binned into threat categories, and most of the
area peaks in the moderate (3 of 5) category tomorrow, jumps up to
the high (4 of 5) category Sunday, and further increases into the
extreme (5 of 5) category on Monday.

So really...any way you slice it, it`s going to be hot and
unseasonably so. Especially given the holiday weekend and our
relative lack of acclimation to summer conditions, it could
potentially be dangerous if you don`t take steps to keep yourself
cool and minimize exposure to the conditions...especially if your
holiday plans are active ones! Fortunately, being aware of the
expected heat and taking proactive steps to mitigate their impacts
will do much to prevent heat illness/injury.

Beyond Monday afternoon, we do look to see some improvement as far
as the heat goes. A low pressure center passing through the Great
Lakes looks to nudge a weak, backdoor front through the area
Monday night. This won`t do a whole lot to bring relief to the
area, but it will help modestly. Look for temperatures to step
down slightly into the lower 90s on Tuesday, around/just above 90
on Wednesday, and even back to seasonably average around/just
below 90 degree highs on Thursday. Of course, this weak front will
also mean potential for some showers/storms Monday night...and
then we`ll be playing the "Look to North Texas" game deep into
next week, as a northwest flow pattern aloft emerges.
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&&

.AVIATION...
(18Z TAF Issuance)
Issued at 1231 PM CDT Fri May 24 2024

Though conditions have been broadly MVFR, anticipating that trends
will bring us to widespread VFR conditions by or very shortly
after 18Z. Gusty winds out of the south/southeast, with gusts
dropping off in the evening. Winds gradually should come down as
well, though MVFR CIGs should be expected to return as well. Like
today` tomorrow`s return to VFR likely to be around 18Z, but have
only explicitly included it in the extended portion of the TAF at
IAH, and will leave more precise timing to the next cycle.

&&

.MARINE...
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Issued at 257 PM CDT Fri May 24 2024

Moderate southeast and south winds will prevail through the
Memorial Day weekend, occasionally becoming stronger and gusty.
Seas will remain somewhat elevated...generally ranging between
4 and 6 feet. Recreational boaters are urged to exercise caution
this Memorial Day weekend and check the current conditions and
forecast before venturing out.

At area beaches, this moderate to strong onshore flow will also
result in tide levels elevated above the typical astronomical
tides, and also make dangerous rip currents likely. Given the
fair, hot weather for the holiday weekend, beaches will likely be
busy, and beachgoers will need to be alert to water conditions.
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&&

.PRELIMINARY POINT TEMPS/POPS...
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College Station (CLL)  75  95  77  94 /  30   0   0  10
Houston (IAH)  78  94  78  94 /  10   0   0   0
Galveston (GLS)  80  89  82  86 /  10  10  10   0
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&&

.HGX WATCHES/WARNINGS/ADVISORIES...
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TX...Beach Hazards Statement until 11 PM CDT this evening for
     TXZ436>439.

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

$$

SHORT TERM...Luchs
LONG TERM....Luchs
AVIATION...Luchs
MARINE...Luchs