Area Forecast Discussion
Issued by NWS Houston/Galveston, TX

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FXUS64 KHGX 230907
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
407 AM CDT Sat Mar 23 2024

...New HYDROLOGY...

.SHORT TERM...
(Today through Sunday Night)
Issued at 306 AM CDT Sat Mar 23 2024

Today is ridging day! Water vapor imagery shows the axis of a weak
midlevel ridge is currently over West Texas and the Panhandle, and
will traverse across the state today. Light, generally northwesterly
winds are currently prevailing across the area, thanks to the last,
lingering effects of our coastal low - now making a mess around the
Delmarva. However, that low will continue to move off, and a
decently strong high moving from the Northern Plains to the western
Great Lakes will gradually assert its influence over the midsection
of the country. This far south, the influence will not be strong,
but should succeed in turning our winds more to the northeast and
even easterly through the day.

Of course, with the ridging building in and a stretch of subsidence,
we can expect a mostly sunny sky today. This should make for a
seasonably cool start today, almost exactly on the button for late
March averages. The spring sun will also help push in the other
direction this afternoon, and I chose to overshoot the guidance a
little bit, going with highs for most in the middle to upper 70s,
and even some isolated hot spots gunning for 80. The main exception
is up north, where some remnant cooler, post-frontal air remains.

Tonight does not look as chilly as early this morning, but still not
much warmer than seasonal averages, so it will still feel pretty
seasonable out there. As the surface high drifts off to the eastern
Great Lakes, we`ll see winds tonight continue to veer around to
become onshore. This will be enhanced by lee cyclogenesis off the
Front Range, with a developing surface low over the Central Plains
spurred by the next incoming upper trough. As usual, when onshore
flow begins to funnel in Gulf moisture, our temperature floor begins
to rise. We`re just starting this process, so the impact will be
small tonight. Expect a bigger change tomorrow night, as lows in the
50s give way to lows in the 60s Sunday night. In between, Sunday
looks warm again, but I keep the temps toned down to the consensus
of guidance in the lower to middle 70s, as clouds should be on the
increase. Today pretty clearly looks like the warmer of the weekend
days.

Finally, very late Sunday night, some low chances for rain starts
to creep across our northern border. That low from the last
paragraph? It should be in eastern Nebraska, on its way across the
Missouri River towards Iowa. While its cold front should just be
making its way out of the Panhandle at this time, there looks like
there will be some sort of pre-frontal trough or dryline that
will provide a focus for convective development. But most of the
action here is really holding off until Monday, so I`ll not get
too much into it here, and hand it off to the long term forecaster
now (which, thankfully with quieter weather tonight, is not also
me).

&&

.LONG TERM...
(Monday through Friday)
Issued at 306 AM CDT Sat Mar 23 2024

As promised by the short term forecaster, the weather becomes more
active on Monday. A deep layer trough over the Rockies will eject
eastward, increasing PVA over southeast Texas. Mid/upper synoptic
forcings will allow for the continued intensification of the
aforementioned sfc low as it moves northeastward over the
central/northern plains. The resulting steepening LL gradient will
strengthen southeasterly / onshore flow, surging tropical
moisture into southeast Texas from the Gulf. Deterministic and
ensemble guidance suggest PWATs reaching 1.50-1.60" by the morning
and early afternoon hours on Monday. These rising LL moisture
levels coupled with the approaching cold front and large scale
mid/upper ascent will bring a CWA-wide chance of showers and
thunderstorms. But PoPs will vary quite a bit across the CWA.
Generally speaking, large scale ascent should increase as one
heads north. Monday`s PoPs range from as low as 20-30% in our CWAs
far southwest (Matagorda Bay area) to 60-70% along I-10 to as
high as 80-90% across our northern Piney Woods counties. Some of
the dynamics in place are expected to support a few stronger
thunderstorms. But Monday`s set up is by no means a slam dunk for
severe weather. For now, the severe threat is considered
conditional with strong winds being the primary concern.

Beyond Monday, the weather appears mostly quiet. An UL disturbance
is expected to bring more cloudiness to our northern counties on
Wednesday. If we can muster enough moisture, perhaps Wednesday`s
system could produce a few showers. We are keeping the forecast
for Wednesday dry for now. The Tuesday-Friday time frame is also
expected to feature a warming trend thanks to increased mid/upper
ridging and WAA on the backside of an eastward progressing sfc
high. Tuesday-Wednesday high temperatures are expected to range
from the upper 60s in our northern counties to low/mid 70s farther
south. Lows are forecast to be in the 40s and 50s. By week`s end,
much of inland southeast Texas could be in the low 80s (70s near
the coast) with overnight lows struggling to drop below the 60s.


&&

.AVIATION...
(06Z TAF Issuance)
Issued at 1148 PM CDT Fri Mar 22 2024

Skies cleared out this evening, and the latest models are showing limited
cloud return. Will carry FEW025 for possible redevelopment and see how
things unfold over the next several hours. Also, winds have been slow
to weaken, but still expecting this to happen overnight. The rest of
the TAFs have for the most part been left the same with just cirrus
for clouds. Winds should still come down overnight (5-10 knots inland,
10-15 knots coast), and look for these speeds to mostly persist into
the early afternoon hours tomorrow. By tomorrow evening, SE winds are
back as high pressure moves off to the east, and look for these winds
to increase to 15 to 20 knots and gusty during the day on Sunday under
a tightening pressure gradient.  42

&&

.MARINE...
Issued at 306 AM CDT Sat Mar 23 2024

Today`s winds will gradually weaken while veering to the east,
then eventually southeast. A strengthening and elongating
southeasterly fetch is expected to develop on Sunday into Monday,
ahead of an approaching cold front. Small Craft Advisory level
winds are possible as early as Sunday and likely by Monday. The
fetch will result in increasing seas, reaching 7 to 10 feet
(occasionally higher offshore) Sunday night into Monday. Winds
gusts could approach gale force offshore on Monday morning. Showers
and possibly a few thunderstorms are possible on Monday as the
front pushes offshore. Weaker northwest winds are expected in its
wake by Tuesday, before winds gradually veer to the northeast on
Wednesday and southeast by late Thursday or Friday.

&&

.HYDROLOGY...
Issued at 405 AM CDT Sat Mar 23 2024

Flood warnings continue overnight on the San Bernard River at Boling
and Sweeny. Both have crested and are now seeing river levels fall,
and should be below flood stage later this morning.

Elsewhere on the San Bernard, river rises have come in just below
previous forecasts, and so revised forecasts now crest the river at
this gage just below flood stage. Given that the forecast crest is
less than a foot below flood stage, we will continue to closely
monitor the gage.

As a more long term concern, the Trinity River and Riverside is just
below bankfull, and forecasts still eventually bring it to just
below flood stage. Of note, these forecasts do not yet incorporate
any potential rainfall early next week, so we`ll need to continue to
keep a close eye on future forecasts at this point.


&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)  74  57  74  64 /   0   0   0  20
Houston (IAH)  79  57  75  67 /   0   0   0   0
Galveston (GLS)  73  63  73  67 /   0   0   0   0

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...Small Craft Should Exercise Caution until 7 AM CDT this morning
     for GMZ330-350.

     Small Craft Advisory until 7 AM CDT this morning for GMZ335-355-
     370-375.

&&

$$

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


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