Area Forecast Discussion
Issued by NWS Houston/Galveston, TX

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000
FXUS64 KHGX 030007
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
607 PM CST Sat Mar 2 2024

...New AVIATION...

.SHORT TERM...
(This evening through Sunday Night)
Issued at 154 PM CST Sat Mar 2 2024

A stubborn, low-level cloud deck has been slowly eroding overhead
this afternoon. As I type, some areas have managed to break into
full sunshine while others remain under the gray gloom of these
stubborn clouds. More of you will begin to see the sun as the
cloud deck erodes. But some of you, especially near the coast,
could struggle to see the sunshine this afternoon. Areas where the
sun has already come out should make a run for the 80 degree
mark. Most areas should reach at least the mid 70s. Near the
coast, temps will struggle to reach 70F.

Moist, Gulf air will continue to pool into southeast Texas through
tonight. Meanwhile, a low-level inversion is likely to become
more stout, especially if forecast soundings have anything to say
about it. This will provide a prime environment for another round
of low clouds and fog tonight into tomorrow morning. Be advised
that areas of dense fog (visibility at or below 1/4 mile) are
possible. A Dense Fog Advisory may be warranted for later tonight
through tomorrow morning. Temperature wise, overnight lows are
expected to average in the low 60s.

Sunday`s atmosphere is looking similar to today. Therefore, we are
keeping a little more cloud cover into the afternoon since those
pesky low clouds could easily be stubborn again. Afternoon
temperatures are expected to be in the 75-80 degree range.
Probably a little cooler at the coast where patchy fog could
linger into the afternoon. Fog and low clouds will be possible
again Sunday night. As we approach day break on Monday, there
could even be a few rain showers as the next system approaches.
But I`ll let the long term meteorologist get into that.

Take it away long term!

Self

&&

.LONG TERM...
(Monday through next Friday)
Issued at 154 PM CST Sat Mar 2 2024

The long term portion of the forecast is virtually bookended by two
frontal passages with more significant chances for showers and
thunderstorms. In between is a stretch of weather that will be
"drier", but not necessarily fair or even entirely dry as an
unsettled pattern remains aloft, and low level onshore flow quickly
returns. While perhaps not a terribly satisfying forecast, there is
at least a little more confidence in more than just the broadest
strokes, so a step forward from yesterday.

Monday into Tuesday begins things off, and we start with our first
good shot at rain and some thunderstorms. There may even be a chance
at a strong to severe storm, but the limited severe threat is more
likely to be just to the east of our area. We do have some things
working in our favor - persistent onshore flow will push dewpoints
up into the middle to even upper 60s, and we should have ample
moisture and instability with the prevailing warm, humid air.
Directional shear should be good, though it will be mitigated
somewhat by relatively low wind speeds - not even progged to be 50
knots at 500 mb. Further aloft, we have a decent...ish position with
the upper jet Monday and Tuesday. We`ll be in a divergent quadrant
each afternoon, though on Monday we are somewhat removed from the
jet core, and Tuesday`s setup doesn`t look to materialize until
after the weak front is through, at which point rain chances will be
slight to nil. All these words to say...expect shower and storm
development from Monday through to Tuesday morning. The higher end
storms have a chance to become strong to severe, but the threat is
marginal and most storms will be weaker.

Tuesday afternoon into later Wednesday night will be the closest
thing we get to a decidedly post-frontal period after the weak cold
front moves through earlier in the day on Tuesday. But we shouldn`t
really expect a solid period of offshore winds, likely more just
Tuesday will feature variable, generally offshore winds for
most...and out over the Gulf, the front may dissipate before really
turning the winds. The closest we may get there is a leading surface
trough over the Gulf backing winds more to easterly Tuesday morning
before onshore flow returns area-wide Tuesday night. As a result,
post-frontal cold advection will be minimal at most, and we`ll
likely barely notice a temperature change, if there is one at all.
We should get the clouds to scatter out later Tuesday afternoon
and Tuesday night, but the return of onshore flow that night will
bring back clouds and erase whatever little dip in humidity
occurs. There`s a little more confidence in keeping things dry in
the Tuesday afternoon to Wednesday afternoon period, and a drier
Wednesday is now the top cluster in the ensemble cluster analysis,
albeit still without a strong signal that it is becoming the
dominant cluster.

Wednesday night into Friday brings the next window for rain and
storms ahead of another cold front moving through the course of the
day Friday. With a more amplified upper trough helping to support
this one, we could be looking at a more traditional springtime
Plains storm system, complete with non-zero chance at stronger
storms. This is not the prettiest setup though, so there`s not a lot
of confidence yet in where, when, or even if stronger storms will
occur in our area. The upper trough looks amplified, but strung out
and positively tilted, which often enhances the cap for our area.
Frontal timing will also be important, as odds are it will be the
focusing feature for convection. If it comes through wrong,
particularly too early, we`ll be forcing convection without the
benefit of peak diurnal heating. At this lead time, there are some
boxes checked, and others that look like they could be a failure
mode. I`m with SPC on this one right now - "Predictability too low".

Because of the more amplified pattern, however, there is more
confidence at the very very end of the forecast period that we`ll
get a more meaningful post-frontal change of airmass. Offshore winds
will be ushering in noticeably cooler and drier air, which means
fair weather for the weekend. The cooling will be so noticeable,
that our temps look to fall all the way to around or a little below
average! Okay, that`s not the best sell for anyone who likes it
colder...but it will be an improvement, and the warm weather fans
won`t get too chilly with it, so we got that.

&&

.AVIATION...
(00Z TAF Issuance)
Issued at 546 PM CST Sat Mar 2 2024

A mixture of VFR to MVFR ceilings will continue early this
evening, before conditions deteriorate tonight. Low ceilings and
reduced visibility due to fog will develop/move inland from the
coast, resulting in MVFR to IFR conditions. Periods of SCT to BKN
LIFR conditions cannot be ruled out, especially from early
through late Sunday morning. Conditions will slowly improve to
high-end MVFR and VFR conditions in the afternoon. Light south to
southeast winds will prevail through the period.

JM


&&

.MARINE...
Issued at 154 PM CST Sat Mar 2 2024

Fog is the primary concern for marine interests this week, as water
temperatures sit right around 60 degrees, while warm and humid air
with dewpoints in the mid to upper 60s are expected to stream over.
We got a taste of that last night, with patchy fog bringing
visibility down to around 6 miles in spots over the Gulf, and some
of the dense radiation fog over land drifting over Matagorda Bay.
With that air mass only strengthening, we should see fog return
again tonight, and it can already be seen lurking in webcams along
the Gulf coast. While the potential for dense fog may be higher
tonight, I do think impacts will still be more limited for most,
with tomorrow night having a better shot at dense fog. A weak
surface trough over the Gulf will back winds a little more to the
east-southeast, typically a more favorable fetch for sea fog. Where
rain and thunderstorms develop Monday into Tuesday in association
with the incoming cold front, we`ll be able to mix out the fog and
get some improvement on that front...at the cost of rain and storms,
though.

With this weak front unable to scour out moisture or even
meaningfully shift the winds, we can expect to see fog back into the
picture as early as Tuesday night. It turns into rinse and repeat,
as this puts us right back into a pre-frontal environment for the
next cold front sweeping through on Friday. This one will be able to
bring offshore winds and a drier airmass, and should finally put an
end to a sea fog threat.

On the bright side, devoting so much space to fog likely means that
winds and seas are not a serious concern, and that is indeed the
case. Light to moderate winds and low seas should largely prevail
through the week, except in the immediate vicinity of any
thunderstorms both early and late in the week when fronts move
through. We should finally see an increase in winds and seas as
stronger post-frontal northerlies develop Friday night into
Saturday.

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)  62  78  64  81 /   0   0  10  40
Houston (IAH)  62  79  65  80 /   0   0  10  60
Galveston (GLS)  63  72  64  73 /   0   0  10  60

&&

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

$$

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


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