351
FXUS64 KHGX 192013
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
313 PM CDT Sun May 19 2024

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

.SYNOPSIS...
Issued at 313 PM CDT Sun May 19 2024

For the first time in a while, we have several days without
rainfall forecast. And even when we do have rain chances on
Wednesday and Thursday, activity may struggle to push too deeply
into our area from the north. Despite that, however, things are
not really quieting down here at The Bureau. Area rivers remain
swollen, with roughly a dozen gages at or forecast to be in flood
stage, with major flooding persisting on the Trinity River. Also,
as rain chances take a break from plaguing us, it will be spelled
by early summer heat, and temperatures may find themselves firmly
into the range of full summer. Some key things to remember about
the week ahead:
- Major flooding continues on the Trinity River, moderate flooding
  on the East Fork San Jacinto, and minor flooding on other area
  rivers and streams. Please continue to heed the advice of local
  officials, and try to avoid flooded areas as possible.
- Expect heat to build through the week, as we may see highs begin
  to push towards the mid-90s and peak heat index values around
  105 degrees towards the end of the week. Though not rising to
  the level of our heat advisory threshold, this is still strong
  early heat, and it will be important to practice heat safety as
  we acclimate to summer conditions. This is particularly
  important for any remaining areas with significant power
  outages, as it will be difficult to find respite in air
  conditioned locations.
- The "sneakier" avenue of heat will also be on the scene this
  week, with warm temperatures overnight. After Monday morning, it
  will be difficult for anywhere in the area to fall below 70
  degrees, and later in the week, lows only in the upper half of
  the 70s are expected to expand out from the Gulf coast to become
  widespread.


&&

.SHORT TERM...
(This evening through Monday Night)
Issued at 313 PM CDT Sun May 19 2024

A weak shortwave at 700mb coupled with onshore flow has led to a
scattering of cumulus clouds across SE Texas this afternoon. These
won`t amount to anything more than little cotton ball clouds as WV
imagery reveals a pretty bone-dry airmass and subsidence from high
pressure will suppress vertical growth.

Tonight will feature pretty mild and humid weather as lows loom in
the 70s for most of the area. Locations in the Piney Woods and
Brazos Valley may dip into the upper 60s. With low-levels/surface
allowed to dry out more today, this should keep fog development a
little more sparse tonight into Monday morning. Patchy fog may still
be possible across portions of the Brazos Valley and Piney Woods.

Monday will feature another day of benign weather, and this
meteorologist is pretty thankful for that! The warming trend will
continue as the work week kicks off. Highs for Monday will be in the
upper 80s to low 90s.

One thing to bear in mind, that while the weather will feature
beautiful sunny skies and warm temperatures, the increasing humidity
combined with increasing temperatures will lead to heat indices in
the upper 90s approaching 100F...

Breezier winds may provide some relief from the rising temperatures
tomorrow. A shortwave trough will push through the Great Plains and
generate an area of low pressure. This area of low pressure will
deepen and swing eastward which will lead to a tightening pressure
gradient and consequently increasing winds.

Monday night`s lows will provide little relief from the daytime heat
as temperatures remain in the mid to upper 70s with a muggy feel.
This will be the beginning of the warm trend that will continue
through the long-term period. Echoing the words of the previous
forecaster: Please take precautions to protect yourself and loved
ones from the heat. Make sure to stay hydrated, take frequent
breaks, avoid strenuous activity during the hottest part of the day,
and LOOK BEFORE YOU LOCK!

&&

.LONG TERM...
(Tuesday through next Saturday)
Issued at 313 PM CDT Sun May 19 2024

There is not a lot in the way of PoPs even in the long term, so
let`s just get our chat about that out of the way. Our traditional
summertime subtropical ridge is trying to work its way into the
picture - hence the lack of PoPs - but it is not yet dominant,
with an active northern stream shooting a near continuous string
of upper troughs through, beating back the ridge. Since they`re
only blunting the ridge, I`d expect the impact to our area will
generally be minimal but this is the time of year where we still
have to watch developing convective complexes warily. A
sufficiently developed complex could alter the mesoscale
environment enough to persist into parts of Southeast Texas, even
though the models insist they will all die out before arriving.
Right now, the best days I see for that are Wednesday and
Thursday evenings, when a trough running through the subtropical
jet stream may phase up well with a more significant northern
stream trough. Even then, however, I still only bring slight
chance to chance PoPs to the northernmost stretch of our area,
roughly from Brenham to Huntsville to Lufkin northwestward.

Beyond that, the big story is the emerging summertime conditions,
particularly by next weekend. The NAEFS ensemble mean has 850 mb
temps generally over the 90th percentile (and occasionally
higher, like Monday and Tuesday nights), and by the weekend,
consistently topping the 97.5th percentile. The Euro ensemble mean
850 temps are right in the same ballpark, though perhaps just a
touch lower for the weekend...but only in the sense that large
swaths of the area see things reach the 97.5th percentile, instead
of most/all of the area. In exploring potential alternate
scenarios, I checked out our multi-model ensemble clustering
tool. And...well...it wasn`t very interesting. The top cluster was
consistently very near the multi-ensemble mean for high temps, and
only sporadically in lower clusters showed spotty deviation
slightly up or down. Ultimately, I am seeing pretty high
confidence that we`ll see some typically full summertime
conditions going into the Memorial Day weekend.

What do I mean by "full summertime"? I`m looking at temperatures
rising into the 90s area-wide, with a number of places pushing
into the middle 90s. Combine that with Gulf Coast humidity, and
this will bring us to heat index values peaking out around 105
degrees. These kinds of numbers would be perfectly in place in
July and August, but it is a bit on the high side for late May.
We`re not quite at the point where we`d need heat advisories, but
it is kinda close, it`s a holiday weekend, and a number of people
may still be without power due to last Thursday`s storms as a
complicating factor.

On top of that, things don`t get any better at night. With
persistent onshore flow, high dewpoints will be the overnight
temperature floor elevated. After Monday night, we`ll struggle to
see anywhere in the area fall below 70 degrees, and deep into the
week, lows in the middle to upper 70s will spread outward from the
Gulf Coast to swallow much of the area. This will be particularly
important if getting into air conditioned places overnight is a
challenge, since being unable to find times to shed the
accumulation of heat stress creates a more dangerous situation for
heat illness/injury. Heat stress also tends to have greater
impacts in a largely unacclimated population, which we may see
with this first big outdoor holiday weekend of the summer. Should
numbers drift any higher, advisories are something we might need
to give more serious thought to.

&&

.AVIATION...
(18Z TAF Issuance)
Issued at 1231 PM CDT Sun May 19 2024

VFR prevailing through the period. Included TEMPO for 12-14Z for
a few sites for potential for patchy fog that could lead to MVFR
VSBYs. Otherwise, high clouds expected with light SE winds.

&&

.MARINE...
Issued at 313 PM CDT Sun May 19 2024

Though still drifting back to being more ESE at times, generally
southeasterly winds are coming to prevail across the area today,
and this onshore flow can be expected to persist through the week,
generally around 15 knots across the waters. While most of the
time this will be in the 10-15 knot range, at times they will
drift upwards into the 15-20 knot range, and occasionally prompt
stretches of caution flags.

&&

.HYDROLOGY...
Issued at 312 AM CDT Sun May 19 2024
Updated at 313 PM CDT Sun May 19 2024

Minor to major river flooding continues for parts of Southeast
Texas, particularly along portions of the Trinity, Brazos, and San
Jacinto rivers. The following river points are either currently in
flood stage or are forecast to reach flood stage (as of early Sunday
morning):

MAJOR//
-------
- Trinity River, Liberty
- Trinity River, Goodrich

MODERATE//
----------
- Trinity River, Riverside
- Trinity River, Moss Bluff
- East Fork San Jacinto, New Caney

MINOR//
-------
- Menard Creek, Rye
- Lake Creek, Sendera Ranch Rd.
- West Fork San Jacinto, Humble
- Navasota River, Normangee
- Brazos River, Rosharon
- Brazos River, Richmond (forecast)
- Brazos River, Sugar Land (forecast)
- Brazos River, West Columbia (forecast)

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

Batiste/Luchs

&&

.CLIMATE...
Issued at 312 AM CDT Sun May 19 2024

Still amazed with how much rain parts of our northern counties have
received so far this year. Through May 17th, Huntsville`s (UTS) 50.14
inches was 35.01 inches above normal and was the wettest on record
start to the year (previous record was 22.37 inches in 2004). Huntsville`s
records date back to 4/1/1998.

42

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)  69  89  73  90 /   0   0   0  10
Houston (IAH)  71  90  74  90 /   0   0   0   0
Galveston (GLS)  75  83  77  84 /   0   0   0   0

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&

$$

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