Area Forecast Discussion
Issued by NWS Houston/Galveston, TX

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FXUS64 KHGX 241139
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
539 AM CST Tue Jan 24 2017

.AVIATION...
Strengthening and gusty south winds develop later this morning through
early this evening ahead of a cold front. The day starts with just some
cirrus, then moisture levels rise as the day progresses resulting in
gradually increasing clouds into the evening and overnight hours. Went
with MVFR ceilings at most TAF sites, and have some MVFR visibility
at GLS for possible fog development. Some guidance has IFR/LIFR levels
developing area wide, but currently think winds might stay up enough
to keep the area mostly in MVFR levels. Looking for winds to shift
to the northwest late tonight through tomorrow morning with the passage
of a cold front, followed by gradually decreasing cloud cover as the
day progresses.  42
&&

.PREV DISCUSSION... /ISSUED 341 AM CST Tue Jan 24 2017/

DISCUSSION...
A clear and cool night tonight with light, onshore winds. Some
shallow ground fog may crop up the next night or two in the
foggiest spots, but should not be impactful. Beyond tonight,
there`s not much that stands out - warm temperatures today will
threaten daily records. clouds will also increase ahead of a cold
front expected to pass late Tuesday night/early Wednesday morning.
There may be some isolated showers, but should generally be dry
with the best chance for any rain showers over the Gulf.
Temperatures behind the front look to get knocked down to around
or a bit below seasonal averages, and before they can warm up too
much late in the week, get taken back down to those values with a
front on Saturday. At this time, the first half of next week also
looks quiet.

Today through Wednesday...
Obs across the area are clear and refreshingly cool. IR and WV
satellite imagery show some high clouds scooting from the Big Bend
region across North Texas as a very subtle shortwave moves across
Texas. We look too dry to support those high clouds, but look to
see some lower clouds crop up as low level moisture continues to
be bulked up by the onshore flow. A warm day is expected as a
deepening low in the Central Plains increases southwesterly flow
across the area. A tie of the current record high is explicitly
forecast at Intercontinental, and the other three climate sites
(College Station, Hobby, Galveston) are all within 4 degrees of
the record, so we`re looking for at least an outside shot for
records across the area.

Cloud cover tonight will keep low temperatures up considerably
higher than Monday night. Truth be told, the lows are not likely
to be much cooler than Wednesday`s highs, as the front crossing
the area through the morning hours should allow cooler air to
significantly blunt the rise in temps. Beyond that and the wind
shift, there`s not likely to be much else to notice the frontal
passage. Much of the guidance suggests isolated to scattered
showers popping up near the coast, and wouldn`t be surprised by
that at all, but generally think the column will not be able to
recover enough, and most should stay dry. Generally a fan of how
the NCAR ensemble members are handling things, with showers really
not cranking up much (or at all) until the front is offshore.

Thursday through Saturday...
The upper trough supporting the low attached to our Wednesday
front promptly does a faceplant, leaving a midlevel pattern with
such a positively tilted trough, it nearly looks zonal. As such,
don`t expect things to get much colder, opting instead to keep
temps roughly near normal. Expect some subtle warming, likely due
to some veering in winds and sunnier skies than anything else. But
before things get too warm, another front comes through Saturday.
Surprisingly enough, this front is a long stringer from a low over
Northeast Canada that`s at least partially related to our
Wednesday low/front. As one might expect, a front so far removed
from its parent cyclone isn`t bound to pack much punch, and precip
looks even more sparse with this front. Though this broad, flat
trough will filter some colder air in, the coldest air will be
trapped far to our north, so just take temps right back to where
they were before the late week warming.

Next week...
An amplifying ridge near the Pacific coast will give some pep back
to the flabby trough, but should do so largely to our east, so
little impact for us. But, what`s interesting is that the Euro,
GFS, and Canadian all leave behind a little patch of vorticity and
lowered heights that don`t quite fill over the DesertSouthwest/Northwest
Mexico, making a little closed/cutoff upper low. That looks to
drift eastward in the first half of next week, but do so in
varying ways, along with significant differences in the northern
stream pattern. Ultimately, this is probably only interesting to
weather nerds like me, without much impact to sensible weather as
a surface high drifts across the northern Gulf Coast. Still, a
stronger low in the Euro implies a need for some low PoPs towards
midweek - I just didn`t get too crazy with it.

Luchs

MARINE...
Onshore winds will strengthen today and tonight. For now, small
craft should exercise caution across the offshore waters (an
advisory is possible), and these caution flags might be needed for
nearshore waters and/or maybe the Bays later this afternoon or
tonight. Some fog development is possible late this afternoon and on
into tonight along the coast and in/around the Bays. A cold front
will swing winds around to the west and northwest tomorrow, and
caution flags are anticipated for parts of the area (especially
offshore waters) through Thursday morning for this strengthening
offshore flow. We will close out the week with light to moderate
mainly northeast to east winds. A reinforcing front will move
through the area over the weekend. Caution and/or advisories are
anticipated behind this front.  42

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)      80  54  66  39  60 /   0  20  10  10   0
Houston (IAH)              82  62  71  43  61 /   0  20  20  10   0
Galveston (GLS)            75  64  70  51  60 /   0  20  30  10   0

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION through late tonight for the
     following zones: Waters from Freeport to the Matagorda Ship
     Channel from 20 to 60 NM...Waters from High Island to
     Freeport from 20 to 60 NM.

&&

$$

Discussion...25
Aviation/Marine...42



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