460
FXUS64 KHGX 070914
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
414 AM CDT Tue May 7 2024

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

.SHORT TERM...
(Today through Wednesday Night)
Issued at 307 AM CDT Tue May 7 2024

While flooding on area rivers remains, and will remain, an issue
for quite some time (see Hydrology section below), we will at
least get a stretch in which the atmosphere will not be actively
making things worse. That`s not to say it will be *totally* dry.
The same gentle isentropic upglide from onshore flow responsible
for giving us our typical nocturnal and early morning stratus this
time of year might manage to squeeze out a short sprinkle in
isolated spots. But the key word here really is "sprinkle". I`m
talking something that you might notice on the windshield at most,
and certainly not even measurable, much less something that would
cause any problems.

No, in the short term, the key concern is going to be one of heat.
Yup, summer is coming...by some unscientific, informal
measures...it already is here. That measure? This specific
forecaster is cranky about having to be outside for any
appreciable length of time. More scientifically, we are looking at
afternoon highs coming in right around 90 degrees, give or take a
few degrees. I`d shade a bit on the cooler end of that range
today, and a bit towards the warmer side tomorrow, based on the
potential for slightly greater cloud cover today. Functionally,
though, this is largely splitting hairs. Either way, we`ll be
looking at temperatures that are a little on the warm side of
early May averages, and plenty of humidity (plus an extra source
of local moisture from floodwaters and saturated ground).

This gives us a couple days where peak heat index values look to
range from the middle 90s to low 100s away from the Gulf today and
tomorrow. This is easily shy of our heat advisory threshold of 108
degrees. However, I did still give a bit of thought to something
simply because this will be our first hot stretch of the year, and
for many places, their first 90 degree-day of 2024 (yes, College
Station, we know, you got one in March). I came down on it being
still too low and not far enough from climatological norms for any
sort of advisory, but our lack of acclimation to the heat did at
least force me to think about it.

And while we`re talking about getting acclimated, take it slow in
doing that. It`s a long summer, there`ll be a lot of heat, and
we`re just getting started here. Most of our bodies aren`t quite
ready for our typical big time summer numbers yet. And while we`re
not there yet, heat illness tends to try to creep in at lower
levels. Another way of looking at heat - the wet bulb globe
temperature - tries to be more applicable to those out doing work
in hot conditions, as opposed to the heat index, tuned to
locations in the shade. If you`ve been in the military, marching
bands, or are a competitive distance runner, you may already be
familiar with the WBGT! Our forecast WBGT values are in a range
that is considered elevated, and indicates a need for more
frequent water and rest breaks, particularly when not heat
acclimated. And that sounds like some real good advice to me.

&&

.LONG TERM...
(Thursday through Monday)
Issued at 307 AM CDT Tue May 7 2024

On Thursday, a frontal boundary/dry line will be stalled out near
the Brazos Valley, just north of our area. Compressional heating and
unimpeded WAA/moisture advection should allow for highs to reach the
80s to lower 90s. A shortwave trough is expected to move overhead
during the day, tapping into PWs of 1.5-1.8" to bring scattered to
isolated storms during the afternoon. The thermodynamics in this
environment look favorable for these storms, featuring ML CAPE in
excess of 3000 J/KG, DCAPE of +1000 J/KG, TEI values in the range of
20-30 with steep midlevel lapse rates over 8 degC/KM. Effective bulk
shear looks to be in excess of 50 knots with cloud layer shear
surpassing 80 knots. However, SRH looks to be weaker, generally
under 100m2/s2 in the lowest 3km. SPC has areas north of I-10 under
a Slight (level 2/5) Risk of Severe weather for Thursday, with areas
to the south under a Marginal (level 1/5) Risk. The strongest of
these storms will be capable of producing damaging winds and large
hail.

The aforementioned boundary should push south Thursday evening as an
upper level trough digs through the Central Plains/Central
Mississippi River Valley, with the front pushing offshore during the
early morning hours of Friday. This will usher in drier and slightly
cooler conditions through the weekend, with highs in the upper 70s
to 80s. Expect benign weather through Saturday as surface high
pressure slides east through our area. Shortwave energy from a
cutoff low over the Desert Southwest passes overhead on Sunday,
allowing rain chances to return as PWs rise to 1.0-1.5 inches. Long
range guidance shows the aforementioned cutoff low traversing
eastward into Texas on Monday, bringing more active weather next
week.

&&

.AVIATION...
(06Z TAF Issuance)
Issued at 1149 PM CDT Mon May 6 2024

Widespread MVFR ceilings have been spreading inland this evening, and
this trend should continue overnight and on into early in the morning.
Areas of IFR ceilings along with patchy fog are possible too. Winds
will start out SW in the morning then become S to SE in the afternoon.
Expecting to see low end VFR ceilings in the afternoon followed by
lowering/expanding ceilings in the evening/overnight hours.

42

&&

.MARINE...
Issued at 307 AM CDT Tue May 7 2024

Light to moderate onshore flow is expected through Thursday ahead of
a frontal boundary. This persistent fetch will bring seas of 3-6
feet in the Gulf, elevated tide levels along the coast, and a high
risk of rip currents across Gulf-facing beaches. High flows from
rivers, creeks and streams will lead to above normal water levels in
the bays and intercoastal water way through midweek, which may make
navigation difficult at times. A weak cold front pushes offshore
during the early morning hours of Friday, potentially warranting
caution flags into the early weekend. Lighter winds and calmer seas
develop on Saturday as high pressure passes overnight.

&&

.HYDROLOGY...
Issued at 246 PM CDT Mon May 6 2024

Although there are periodic chances for scattered showers/storms
this week, this is not expected to result in any additional
flooding. Rivers will remain swollen for days (possibly weeks).
Do NOT go around barricades and stay out of the floodwaters.
Do NOT return to homes until officials deem that it is safe.

Minor to major river flooding continues for parts of Southeast
Texas, particularly along portions of the Trinity, San Jacinto, and
Navasota rivers. The following river points are either at or
forecast to go into Major flood stage as of Monday afternoon:

- Trinity River (Liberty): Major Flood Stage
- Trinity River (Goodrich): Major Flood Stage
- Trinity River (Moss Bluff): Major Flood Stage
- West Fork San Jacinto (Humble): Major Flood Stage
- Navasota River (Normangee): Moderate to Major Flood Stage

Remember to heed any instructions from your local officials and to
never travel through 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 continues.

Also of note is that the downstream runoff from the previous
rainfall will cause continued rises along the Brazos River through
the end of the week. The Brazos River at Sugar Land, Rosharon, and
West Columbia are forecast to rise into minor flood stage at the end
of the work week and through the weekend.

Batiste

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)  90  73  90  74 /   0   0  10   0
Houston (IAH)  89  75  90  75 /  10  10  10   0
Galveston (GLS)  83  76  85  76 /  10  10  10   0

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...High Rip Current Risk through this evening for TXZ436>439.

GM...None.
&&

$$

SHORT TERM...Luchs
LONG TERM....03
AVIATION...42
MARINE...03