JANUARY 2018 - Seasonal WX Week/Pacific Front Saturday

[unome]

disregard, sry - that was a retweet by CenterPoint but from the 11th


http://www.wrh.noaa.gov/zoa/mwmap2.php?map=zhu
http://www.wrh.noaa.gov/zoa/mwmap2.php? ... =0&limit=2

[don]

Area Forecast Discussion
National Weather Service Houston/Galveston TX
357 PM CST Mon Jan 15 2018

.DISCUSSION...
It is so nice to see temperatures in the mid/upper 60s today. So
wish I could be outside to enjoy instead of bringing the bad news.
What`s that saying? If you don`t like the weather in Texas just
wait 5 minutes? That`s the forecast for tonight/tomorrow. So let`s
get to it.

Currently the arctic cold front is pushing into Red River region
and north Texas. Latest surface obs at 12Z show a 1048-1050mb high
sitting over NE Montana/NW North Dakota. Water vapor imagery shows
that nice closed low over the Great Lakes and broad vorticity
maximum over the Plains swinging southward. Upper air analysis
shows highly amplified pattern with ridge over the western U.S.
driving the polar jet due south over the Plains.

Tuesday...This is probably one of my top 5 toughest most
challenging forecasts to make and one of the toughest forecast
decisions to make. Big thanks to our forecast team collaborating
on this but 12Z models all show very similar trends. Ensembles
like SREF/GEFS seem to be showing something similar.

First thing we saw was temperatures in the boundary layer are
trending colder so we had to trend surface temperatures colder and
sooner than previous forecast. This calls for freezing
temperatures for most of the day on Tuesday with precipitation
falling.

Second the transition of precipitation types looked on track with
a transition Tuesday morning from rain - freezing rain - sleet -
snow. Model soundings from NAM/GFS show this trend. The ECMWF also
showed colder 850MB temps by 18Z Tuesday indicating a similar
trend. There is a fight between the moisture over the frontal
surface and precip falling versus the drier boundary layer air
coming into from the north. This could allow for precip to end
sooner than expected but it will have to overcome quite a bit of
thermodynamic wet bulbing to do it.

Third increase in frontogenetic lift at several levels. GFS/NAM
all show frontogenesis at 925-850mb and 850-700mb layers. There is
also jet stream configuration with the right entrance region over
much of SE Texas and quite a bit of 500-300mb Q vector
convergence supporting large scale lift. These seem to come
together a little bit late but still lift over the area 18Z
Tuesday to 00Z Wednesday. This all suggests possible banded
precipitation and you even see hints of that in the QPF output in
the models. I`m not going to get into a discussion of CSI and
lapse rates but cross sections do show pockets of CSI and steeper
lapse rates in these areas. Frontogenesis will be driving most of
the banding anyway.

Fourth we need to emphasize freezing rain/sleet as the primary
threat for most of the area. Most ice accumulations will be from a
few hundredths to a tenth of an inch. Banding could lead to
higher amounts of ice leading to need a winter storm warning. With
this potential in mind, we decided on a winter storm warning for
areas along and north of Interstate 10. Farther north there could
be a band of snow from Brenham/Conroe/Livingston north with
generally 1 inch of snow possible which would fall on already icy
conditions from freezing rain/sleet prior to snow. There very
well could be some sleet/snow late afternoon/evening in the
Houston area but freezing rain will be the main issues south of
Conroe.

Precipitation should come to an end Tuesday night with low
temperatures Wednesday morning requiring a hard freeze warning. In
the extended forecast there looks to be a chance of rain Friday
with warm air advection. This continues Saturday into Sunday with
another front pushing through Sunday. This time it looks like a
line of showers and a few thunderstorms Sunday. High pressure
builds in with more cold conditions.

Overpeck

[MontgomeryCoWx]

While we are focused on our imminent winter worries, I couldn’t help but notice the large volcanic eruption in the Philippines. Events like this tend to effect weather patterns greatly.

[sau27]

Noticed it will also be quite windy tomorrow. Curious how this is going to impact the speed with which ice accretion begins due to evaporative cooling of surfaces.

[MontgomeryCoWx]

Brazos, Walker and Grimes county schools already closing...

[stormlover]

Rgem is really nice
https://www.tropicaltidbits.com/analysi ... 11518&fh=6

[WeatherDuck]

Hutto ISD in Williamson County announced it will be closed Tuesday.

[DoctorMu]

Texas A&M classes are cancelled tomorrow. That virtually NEVER happens.

[MRG93415]

Waller ISD just announced school closed tomorrow.

[MRG93415]

Cy-Fair just cancelled school. HISD should be next.

[WeatherDuck]

Several Central Texas ISDs have already announced closures for tomorrow.

[srainhoutx]

Light rain falling across NW Harris County. In about 12 hours it should be a different story in my neighborhood. Stay safe and stay off the Freeways and Beltway if possible tomorrow.

[Cromagnum]

Schools in lake Jackson closed tomorrow. Give me a break...

[MRG93415]

HISD just cancelled

[sambucol]

GCCISD in Baytown have cancelled school tomorrow

[jasons2k]

Conroe ISD has cancelled.

[mckinne63]

Stay safe and stay off the Freeways and Beltway if possible tomorrow.

I'm in Stafford and work in SW Houston, Beltway 8 Westchase area. I can work from home so probably a good idea to just stay put? I usually get in early and would be able to leave early.

[srainhoutx]

Stay safe and stay off the Freeways and Beltway if possible tomorrow.

I'm in Stafford and work in SW Houston, Beltway 8 Westchase area. I can work from home so probably a good idea to just stay put? I usually get in early and would be able to leave early.

Since you can work from home, why risk this event over achieving current expectations? I continuing to see more and more evidence of mesoscale banding features developing around noon and continuing into the afternoon/early evening suggesting potentially higher precipitation totals. Typically we only get about 4 to 6 hours of advance indications where the heaver precipitation will fall. It does not take much ice to create a travel nightmare in Metro Houston from my experience of winter weather events in SE Texas over the last 50+ years. If I were in your shoes, I'd stay put... but that's me...

[kayci]

any info on Brazoria and Galveston Counties as far as timeline? Nervous about sending my young son driver to work.
Input would be appreciated.
Thanx

[kayci]

Alvin ISD just cancelled.