January 2020: Unsettled WX Week Ahead

[Kingwood36]

GEFS Members starting to get awfully noisy for frozen precip next Friday Jan. 17th into the following week across parts of Tex

[don]

Yeah i wouldnt be surprised if the winter storm showed back up in the models. As the operational GFS still shows a ice storm next week but has pushed it up north into Oklahoma and Arkansas. I wouldnt be surpised if the convegence zone shifted back south into Texas as weve sometimes seen in the past with these setups. I also think something looks fishy on the way the models are handling the shallow cold airmass as some of the models show a 1045mb+ High coming down the plains and then getting shunted to the east without even a freeze in southeast Texas if you believe the 12z GFS. I find that hard to belive with such a strong high comming down the plains and our source region being so cold. Just something to watch over the next week.

[Cpv17]

Yeah i wouldnt be surprised if the winter storm showed back up in the models. As the operational GFS still shows a ice storm next week but has pushed it up north into Oklahoma and Arkansas. I wouldnt be surpised if the convegence zone shifted back south into Texas as weve sometimes seen in the past with these setups. I also think something looks fishy on the way the models are handling the shallow cold airmass as some of the models show a 1045mb+ High coming down the plains and then getting shunted to the east without even a freeze in southeast Texas if you believe the 12z GFS. I find that hard to belive with such a strong high comming down the plains and our source region being so cold. Just something to watch over the next week.

I’m also wondering the same thing. Doesn’t make sense to me.

[harp]

Yeah i wouldnt be surprised if the winter storm showed back up in the models. As the operational GFS still shows a ice storm next week but has pushed it up north into Oklahoma and Arkansas. I wouldnt be surpised if the convegence zone shifted back south into Texas as weve sometimes seen in the past with these setups. I also think something looks fishy on the way the models are handling the shallow cold airmass as some of the models show a 1045mb+ High coming down the plains and then getting shunted to the east without even a freeze in southeast Texas if you believe the 12z GFS. I find that hard to belive with such a strong high comming down the plains and our source region being so cold. Just something to watch over the next week.

I’m also wondering the same thing. Doesn’t make sense to me.

How strong is that SE ridge? Isn't that a key player here?

[don]

That can vey well be the case,having said that models sometimes underestimate the ability for dence shallow air to over power the effects of the ridge. As we've seen many times throughout the years.

[kyzsl51]

If I remember correctly the models backed off and on for most recent winter events?

[Cromagnum]

Main line looks to be in central texas by mid morning. I dont like that discrete look ahead of it.

https://ibb.co/K0MCG87

[MontgomeryCoWx]

If I remember correctly the models backed off and on for most recent winter events?

Every winter event in recent memory has jumped on and off the models. The only one that really took me by surprise was the December snow in 2017, when it popped up on the HRRR the day of, then dumped 5.5 inches in CS and an inch in Magnolia.

[Cpv17]

Main line looks to be in central texas by mid morning. I dont like that discrete look ahead of it.

https://ibb.co/K0MCG87

If we can remain rain free with some peaks of sun throughout the day then watch out!! To me that’ll be key.

[Cpv17]

Yeah i wouldnt be surprised if the winter storm showed back up in the models. As the operational GFS still shows a ice storm next week but has pushed it up north into Oklahoma and Arkansas. I wouldnt be surpised if the convegence zone shifted back south into Texas as weve sometimes seen in the past with these setups. I also think something looks fishy on the way the models are handling the shallow cold airmass as some of the models show a 1045mb+ High coming down the plains and then getting shunted to the east without even a freeze in southeast Texas if you believe the 12z GFS. I find that hard to belive with such a strong high comming down the plains and our source region being so cold. Just something to watch over the next week.

I’m also wondering the same thing. Doesn’t make sense to me.

How strong is that SE ridge? Isn't that a key player here?

Actually the CPC is thinking that the cold could work it’s way down to Louisiana, but not so much Texas.

[Cpv17]

After just looking at the latest NAM and HRR, neither of them look very impressive for southeast TX especially south of 10.

[don]

Area Forecast Discussion
National Weather Service Houston/Galveston TX
359 PM CST Thu Jan 9 2020

.DISCUSSION...

Bottom Line...The main forecast concern remains the development
of severe storms on Friday evening and into the overnight hours
(see Long Term section for details). The Storm Prediction Center
continues to place most of our forecast in an Enhanced risk area
for severe weather. Initial discrete storm development is possible
in the late afternoon to early evening hours ahead of an
advancing surface cold Front. The threat will later transition to
a squall line/QLCS along the frontal boundary as it moves eastward
across SE TX between around 10PM to 3AM. Severe threats
associated with this line of storms will include strong damaging
winds, hail, and isolated tornadoes embedded within the line. Be
sure to have a way to receive up to date forecast and warning
information, as well as a plan in place to take action in the
event a warning is issued.

Cady


.SHORT TERM [Tonight Through Friday]...

Mostly cloudy to cloudy skies can be expected across Southeast Texas
tonight and Friday ahead of the next storm system. Today`s gusty
south to southeast winds will weaken a little tonight but are
expected to be even stronger during the day tomorrow with the help
of a strengthening low level jet. Wind advisories might be needed.
Periods of rain/showers can be expected too with rainfall totals on
the light side due to the rapid northward movement of the activity.
Instability begins to increase as the day progresses, and we could
see some thunderstorm development starting in the afternoon (lower
chances of anything strong or severe). The much bigger risk for
severe weather is later Friday night (see Long Term section
below).


Temperatures will struggle to cool down tonight with the onshore
flow in place. In fact, the forecasted lows in the mid to upper 60s
are warmer than the expected high temperatures for this time of the
month, and record high mins might be possible (especially the
Houston and Galveston areas that should not cool down prior to
midnight). After the warm start in the morning, high temperatures
should easily reach the mid 70s (maybe upper 70s) areawide. 42


.LONG TERM [Friday Night Through Thursday]...

Confidence remains high regarding the potential for the
development of severe storms on Friday evening and into the
overnight hours. Global models continue to indicate the entrance
of an amplified upper level trough into the south central CONUS on
Friday afternoon. An associated developing surface low will
accompany the entrance of this feature, tracking northeastward
into the central plains. Convective lift ahead of and along a
surface cold front extending southwestward from this area of low
pressure will be the main driver of severe storms heading into
Friday evening as the frontal boundary pushes eastward through
Central and Eastern TX.

Today`s model guidance continues to indicate an environment
favorable for severe convection. A strong low level jet of around
50 to 60 knots will provide enhanced moisture to SE TX throughout
the day on Friday, with both global and high resolution models
showing PWAT values reaching the 1.5 to 1.75 in range. This
enhanced moisture, along with widespread bulk shear values
upwards of 50 kts and 0-1km SRH values of around 300 m2/s2, will
favor the development of storms beginning Friday evening. Furthermore,
models remain trending upward with CAPE values (potentially
reaching up to 2000 J/kg in the near storm environment) and
continue to show mid level lapse rates of 7-8 degC/km by late
Friday afternoon.

The initial, but less certain severe threat for SE TX will be
ahead of the advancing cold front. Initial convective development
during the afternoon appears to be limited by a decent capping
inversion. However, should the cap erode sufficiently with daytime
heating, the formation of discrete supercells in the early evening
hours (around 6PM to 9PM) is not out of the question. Latest high
resolution guidance is split regarding the extent of any
development ahead of the line. However, should any development
occur, all severe threats will be present (strong winds, hail,
and tornadoes).

The main threat, and more certain one for the area, will be the
development of severe storms along the surface cold front as it
advances to the east. By around 10PM, the convective mode is
expected to transition to become linear in nature (i.e. a QLCS).
As the line of storms progresses eastward across SE TX, there
will be a significant threat of strong amd damaging winds as well
as the potential for isolated tornadoes embedded within the line.
The latest guidance continues to push the line through a bit
slower than the previous few forecast periods, reaching the
western zones and Brazos Valley around 10PM-12AM, the metro area
around 12AM-2AM, and the eastern counties/coast around 2-4AM.
Timing of the line will likely continue to be refined as
additional high resolution guidance becomes available.

With this being a nocturnal convective episode, we continue to
stress the need to prepare to take action should a warning be
issued for your area. Nighttime events are especially dangerous
because any storms will be hard to see in the darkness, and many
people are generally asleep and as a result may miss warnings. Be
sure to have a safe place identified, ideally an interior
windowless room in a sturdy structure, that you can quickly get to
if a warning is issued. Furthermore, be sure to have multiple
ways to receive warnings. This might include a mobile app, NOAA
Weather Radio, the internet, or updates from local media outlets.

A clearer weekend looks ahead following the expected severe
weather tomorrow night, as high pressure will settle into the
area. This will result in fairly calm and clear conditions through
early Monday, when the eastward moving surface high will allow for
a shift to onshore winds. As a result, there will be a potential
for scattered showers through the middle of next week. Our next
cold front appears to cross the area on late Wednesday or early
Thursday.

[jasons2k]

I know one thing - the LLJ is starting to really crank now.

[MontgomeryCoWx]

Holy mother of Arctic cold fronts on the 18z GFS. 50 degree drop the beginning of the week of the 20th

[MontgomeryCoWx]

I know one thing - the LLJ is starting to really crank now.

That it is. Got some branches in the yard

[kyzsl51]

Holy mother of Arctic cold fronts on the 18z GFS. 50 degree drop the beginning of the week of the 20th

That would be insane! Has us below freezing for a few days If it were to pan out.

[Cromagnum]

Frankie chimed in. We're screwed now.

https://youtu.be/JSCDhBam-mo

[Cpv17]

Models are looking more and more unimpressive with each passing run for tomorrow’s storms.

[Cromagnum]

Its abnormally warm tonight and tomorrow, then a broken line of windy thunder for 20 minutes. Whoopteedoo.

[Cpv17]

Its abnormally warm tonight and tomorrow, then a broken line of windy thunder for 20 minutes. Whoopteedoo.

My thoughts exactly lol