December 2020

General Weather Discussions and Analysis
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tireman4
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Lary Cosgrove mentioned that January could be interesting.
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tireman4
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00
FXUS64 KHGX 231134
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
534 AM CST Wed Dec 23 2020

.AVIATION [12Z TAF Issuance]...

Conditions already beginning to degrade slightly with most
terminals on the edge of VFR/MVFR CIGs, and even some
sprinkles/light showers south of I-10. Winds will become gusty
deeper into the day. Rain chances should generally go up, but
guidance is now focusing more on areas south/east of IAH.
Conservatively hang onto VCTS as far north as UTS, but better
chances for storms will be for terminals closer to the coast.

This evening into tomorrow morning, TAFs pivot to focus on
improving CIGs and increase in winds. Strong, gusty
northwesterlies expected to build once the front passes, with
gusts as high as 40 knots in the windiest spots (likely GLS, given
its location right on the coast). Expect highest winds to be to
the west (mainly west of TAF sites) and along the coast.

&&

.PREV DISCUSSION /Issued 346 AM CST Wed Dec 23 2020/...

.DISCUSSION...

As clouds increase across the area, along with some light
sprinkles beginning to develop west of Houston, we`re seeing the
first indications of our well-advertised cold front, which will be
the primary focus of the weather for the next week. Look for
chances of rain and isolated thunderstorms to increase through the
day, peaking on and along the front, which will move into the area
late this afternoon, crossing Southeast Texas this evening. While
signals are mixed, there is still a marginal threat of getting a
strong to severe storm or two, and any storms could still produce
gusty sub-severe winds, so make sure those holiday decorations
aren`t going anywhere!

After the front passes, strong and gusty northwest winds will
build, providing further chances to send unsecured Santas flying
tonight, primarily west of Houston. Still, frequent strong gusts
will provide a similar threat for cities along and near I-45, even
if the sustained winds aren`t quite as high as to the west. While
winds should begin to come down towards dawn Thursday, stronger
winds are likely to linger near the coast into Thursday morning
before diminishing. On the waters, this is matched by a gale
warning that begins this evening and carries into tomorrow.

Beyond the immediate weather event, we can expect generally fair
weather, disrupted briefly by a weak cold front late Sunday. The
next opportunity for a more significant frontal passage will come
towards the middle of next week, but still many details to work
out there.




.SHORT TERM [Tonight Through Thursday Night]...

Satellite imagery shows that we have both a veil of cirrus moving
over the northern half of our area, while low stratus is
developing over much of Southeast Texas as well. Expect the
cloud cover to only increase as moisture and lift increase in
advance of an incoming strong cold front. Beyond the clouds, radar
reveals that sprinkles/very light showers are beginning to crop up
west of Houston, but surface obs show no reports of rain yet, so
either nothing is reaching the ground quite yet, or more likely,
where any smattering of drops are reaching ground, is not
happening at an observation station. Like the clouds, look for
rain chances to gradually increase during the day, peaking along
the cold front as it sweeps across the area late this afternoon
and this evening.

Timing the front will be tricky as always, but have generally
tended to favor the short range, high res guidance for having a
better representation of any potential surge of shallow cold air.
Another complicating factor will be additional modification of the
advancing front by a convective cold pool for any thunderstorm
complexes that fire on/ahead of the front. I suspect that this
will be more of a concern for the Louisiana coast, as model
guidance continues to orient the low level jet in a way that is
much more conducive for storms in their area than ours, while the
southwesterly flow tends to create capping problems in our area.
Additionally, while a strong upper jet streak is still expected to
move in, it seems to really move in just a little too late to
really provide support for lift in our area. And really, on top of
that, the moisture axis is perhaps not as impressive as progged
previously, with only 1.2 and 1.3 inches widespread over the area
in GOES imagery, and while a swatch of 1.5 inch air is likely out
there over the Gulf, it may well already be too far east to
provide much impact for us, and instead boost potential over
Louisiana.

Now, after all that pooh-poohing, you may think I have no
expectation for storm development in our area. That`s not entirely
true. While multiple failure factors for severe weather in our
area do seem to be showing up, one factor that does appear to be
really showing up is instability. NBM distributions have picked up
markedly, with the deterministic values now hitting 1500 J/Kg
over the coastal plain southwest of the Houston metro. This is
pretty close to the instability shown by the NAM last night that I
considered more of a high end number. Additionally, even though
the jet streak might be a little slow for maximum effect, we still
have strong winds aloft in place as the nose of that jet works in.
The low level jet is no slouch either, so any storms that do get
going could produce gusty winds, even if they are sub-severe. But,
given the time of year, we have no shortage of unsecured, or
poorly secured holiday decorations out and about.

Once the front works through Southeast Texas, reaching the coast
later tonight, expect rain chances to wrap up pretty quickly,
while strong and gusty northwest winds kick up to usher in a
strong shot of colder, drier air. The winds are expected to be
strong enough that outside of the largely forested areas up
towards the Pineywoods, we have a wind advisory in effect for
tonight - roughly from I-45 westward. For the entire stretch of
our Gulf coast, we also have a wind advisory for tonight, but
those gusty winds should linger into Thursday morning -
particularly for barrier islands with a favorable fetch down
Galveston and Matagorda bays. 925 mb winds are progged to be
approaching 50 knots behind the front, so as long as the bulk of
that manages to mix down, we should definitely see gusts in excess
of 30 mph, and 40ish mph gusts are certainly on the table.

As far as the wind goes, sustained winds will be strongest for
areas west of the Houston metro and will likely end up with the
peak winds of the event tonight. But even as you head east towards
I-45, frequent gusts of 30+ mph can produce similar modest
impacts, especially for the aforementioned holiday decorations.
You will probably want to take a minute or two to make sure those
inflatable reindeer are properly staked down, or tonight they
might get a Christmas Eve Eve test flight!

Enjoy those mid- 70s temps today, because by daybreak Thursday,
we`ll be enjoying temperatures that are a good 30-40 degrees
colder! It does look like the coldest air in the invading airmass
will miss us to the east, so that will blunt the cold shot a
modest amount. Still, we should expect widespread lows in the 30s
and 40s for at least tonight and Thursday night, with isolated
cold spots well north of Houston reaching the freezing mark.


.LONG TERM [Friday Through Wednesday]...

Our gift on Friday will be mostly sunny skies thanks to high
pressure moving overhead. Temperatures will remain on the cooler
side with highs struggling to get out of the upper 50s to low 60s.
The high pressure slides to the east over the weekend returning
southerly flow into SE Texas causing a gradual increase in
temperatures and moisture. A weak upper level trough will move
overhead over the weekend, which combined with the increased
moisture (PWATs climbing to near 1 inch) will bring a slight chance
of showers through the weekend.

A weak cold front/boundary will approach the area late Sunday
increasing the chance of precipitation. Guidance is currently
struggling with how far south this front will make it. Yesterday`s
guidance had it making it all the way off the coast, while today`s
has it stalling inland over SE Texas. There is really not much of a
high pressure building behind the front, so I am leaning more
towards the inland, stalled solution. This means that there will be
a chance of showers into Tuesday and that there could be a 10 degree
gradient in high temperatures for the first part of next week (north
of the boundary could struggle to get out of the low 60s, while
south of the boundary will get into the low 70s). Because there is
really no way of figuring out exactly where this boundary will set
up right now, confidence in the temperature forecast is low.

A stronger system will move across central CONUS midweek next week,
though there is quite a range in the timing of this disturbance. The
EC/Canadian solutions are more progressive bringing the associated
cold front through SE Texas during the day on Wednesday. The GFS is
a bit slower and doesn`t bring the front through until late
Wednesday/early Thursday. So, main take away is that unsettled
weather returns midweek next week.|


.MARINE...

Onshore flow is strengthening tonight, building wave heights -
particularly beyond 20 nm. Beyond that distance, winds are around
the threshold for a SCEC, and expectations are that the persistent
fetch will build waves above their SCEC threshold as well. Winds
may lull slightly later today as a weak surface trough moves in
ahead of the advertised cold front. This trough will help generate
scattered showers and isolated thunderstorms, which will continue
into the evening as the stronger cold front crosses the coastal
waters early this evening. Very strong northwesterly winds
develop in the wake of the frontal passage Wednesday night. The
gale watch that had been in effect is now a gale warning, as
confidence in seeing gales has increased. Winds and seas decrease
Thursday afternoon as high pressure moves overhead, but a period
of small craft advisory or a SCEC will likely be needed for at
least some time on Thursday once gale conditions have ended.
Onshore flow returns this weekend along with the possibility of
showers before a cold front late Sunday.

&&

.PRELIMINARY POINT TEMPS/POPS...

College Station (CLL) 76 35 55 33 61 / 20 0 0 0 0
Houston (IAH) 76 38 54 35 60 / 50 40 0 0 0
Galveston (GLS) 70 43 53 44 57 / 60 60 0 0 0

&&

.HGX WATCHES/WARNINGS/ADVISORIES...

TX...Wind Advisory from 6 PM this evening to noon CST Thursday for
the following zones: Brazoria Islands...Coastal
Brazoria...Coastal Galveston...Coastal Jackson...Coastal
Matagorda...Galveston Island and Bolivar
Peninsula...Matagorda Islands.

Wind Advisory from 6 PM this evening to 6 AM CST Thursday for
the following zones:
Austin...Brazos...Burleson...Chambers...Coastal
Harris...Colorado...Fort Bend...Grimes...Inland
Brazoria...Inland Galveston...Inland Harris...Inland
Jackson...Inland
Matagorda...Madison...Montgomery...Walker...Waller...Washington...Wharton.

GM...Gale Warning from 6 PM this evening to noon CST Thursday for the
following zones: Coastal waters from Freeport to Matagorda
Ship Channel TX out 20 NM...Coastal waters from High Island
to Freeport TX out 20 NM...Galveston Bay...Matagorda
Bay...Waters from Freeport to Matagorda Ship Channel TX
from 20 to 60 NM...Waters from High Island to Freeport TX
from 20 to 60 NM.

SMALL CRAFT SHOULD EXERCISE CAUTION until 10 AM CST this morning
for the following zones: Waters from Freeport to Matagorda
Ship Channel TX from 20 to 60 NM...Waters from High Island
to Freeport TX from 20 to 60 NM.


&&

$$

DISCUSSION...Luchs
SHORT TERM...Luchs
LONG TERM...Fowler
AVIATION...Luchs
MARINE...Luchs
tropiKal
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redneckweather wrote: Mon Dec 21, 2020 9:01 amDid you just make that up to hear yourself talk?
No, these are the trends that have been mentioned consistently by the weather analysts on Twitter.
Long range forecasts as of now are showing solid fronts rolling down after the 1st of the year with some storm systems thrown in the mix. I'm liking it.
Of course there will still be fronts - but, as seen with those forecasts, they're just going to be the really quick, progressive ones with dry passages/minimal rainfall shots, rather than the drawn out, deep weather makers that extend wintry precip chances farther south. Temperatures would still be seasonable.
redneckweather
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tropiKal wrote: Wed Dec 23, 2020 10:23 am
redneckweather wrote: Mon Dec 21, 2020 9:01 amDid you just make that up to hear yourself talk?
No, these are the trends that have been mentioned consistently by the weather analysts on Twitter.
Long range forecasts as of now are showing solid fronts rolling down after the 1st of the year with some storm systems thrown in the mix. I'm liking it.
Of course there will still be fronts - but, as seen with those forecasts, they're just going to be the really quick, progressive ones with dry passages/minimal rainfall shots, rather than the drawn out, deep weather makers that extend wintry precip chances farther south. Temperatures would still be seasonable.
I have had a total of 6 inches of rainfall with just the last 2 cold fronts (not dry...lol) that came down. Today's front will have moisture with it and models are showing a good bit of moisture with the big front around the New Year. Also we are below average temp wise for the month of December because the cold has stuck around. I look for this trend to continue as we push into January.

This is a good winter type pattern for us in Southeast Texas. Wintry weather events are rare down here but if it is to happen, I'm liking this pattern setting up for January.
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redneckweather wrote: Wed Dec 23, 2020 11:10 am
tropiKal wrote: Wed Dec 23, 2020 10:23 am
redneckweather wrote: Mon Dec 21, 2020 9:01 amDid you just make that up to hear yourself talk?
No, these are the trends that have been mentioned consistently by the weather analysts on Twitter.
Long range forecasts as of now are showing solid fronts rolling down after the 1st of the year with some storm systems thrown in the mix. I'm liking it.
Of course there will still be fronts - but, as seen with those forecasts, they're just going to be the really quick, progressive ones with dry passages/minimal rainfall shots, rather than the drawn out, deep weather makers that extend wintry precip chances farther south. Temperatures would still be seasonable.
I have had a total of 6 inches of rainfall with just the last 2 cold fronts (not dry...lol) that came down. Today's front will have moisture with it and models are showing a good bit of moisture with the big front around the New Year. Also we are below average temp wise for the month of December because the cold has stuck around. I look for this trend to continue as we push into January.

This is a good winter type pattern for us in Southeast Texas. Wintry weather events are rare down here but if it is to happen, I'm liking this pattern setting up for January.
I agree. It’s looking pretty good and even if we don’t get any winter weather, rain chances and below average temps look promising.
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jasons2k
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Picked up a nice .45”

Front about to plow through like a freight train.
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DoctorMu
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jasons2k wrote: Wed Dec 23, 2020 7:34 pm Picked up a nice .45”

Front about to plow through like a freight train.
Nothing here, but the lawn is still muddy underneath...quite a line developed south of here! Sugar Land - Houston - to Dayton Lakes and beyond.
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DoctorMu
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N25 G35 winds. Major advection up in Brazos County!
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srainhoutx
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Merry Christmas folks. Looks like I'll have a White Christmas in the Smokies this year. The longe range into January is showing promise for the cold weather lovers. Fingers crossed for a wintery start to a New Year for my Texas/Louisiana neighbors.
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Cpv17
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srainhoutx wrote: Thu Dec 24, 2020 8:05 am Merry Christmas folks. Looks like I'll have a White Christmas in the Smokies this year. The longe range into January is showing promise for the cold weather lovers. Fingers crossed for a wintery start to a New Year for my Texas/Louisiana neighbors.
57 on Storm2K says no winter weather for most of Texas for the next 2-3 weeks. Says the pattern is too progressive.
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Rip76
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Cpv17 wrote: Thu Dec 24, 2020 9:41 am
srainhoutx wrote: Thu Dec 24, 2020 8:05 am Merry Christmas folks. Looks like I'll have a White Christmas in the Smokies this year. The longe range into January is showing promise for the cold weather lovers. Fingers crossed for a wintery start to a New Year for my Texas/Louisiana neighbors.
57 on Storm2K says no winter weather for most of Texas for the next 2-3 weeks. Says the pattern is too progressive.
He’s wishcasting warm weather for himself
:D
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Things are so dry today. The driest airmass of the season. Cleveland is registering a 2 degree dew point and my place has a 10 dp with teens humidity!
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DoctorMu
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TexasBreeze wrote: Thu Dec 24, 2020 3:14 pm Things are so dry today. The driest airmass of the season. Cleveland is registering a 2 degree dew point and my place has a 10 dp with teens humidity!
14° DP in CLL. We're Bathed in sweat! :lol:
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Wouldn’t be surprised to see a big temp bust tonight. DP’s are really low, winds have calmed down, skies are fairly clear, and temps are already in the upper 30’s.
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Kind of weird. It was colder at around 8:30 than it was at 11:30. The temp actually rose.
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srainhoutx
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Merry Christmas everyone!
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srainhoutx wrote: Fri Dec 25, 2020 8:16 am Merry Christmas everyone!
What a beautiful sight merry Christmas to you and your family.
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Merry Christmas to all my forum members and your families be safe.
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srain i trust that you are gonna send us some of that wonderful white stuff later.
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srainhoutx wrote: Fri Dec 25, 2020 8:16 am Merry Christmas everyone!
My heart be still!

Merry Christmas!
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