Texas Winter 2021-2022

[bubba hotep]

Tried to do a break down of this weekends potential system... First part of the story is a streamer of energy moving onshore in Alaska today and then our eventual system is still out over the Pacific. I gave up at that point lol

Now to the ensembles, EPS not much change with about 20% of members showing winter wx for DFW. The 12z GEFS is at about 30%, which is a jump from previous runs. Also of note, the 12/26 18z GEFS had zero members, so this has been a pretty quick onset of a trend.

[cheezyWXguy]

18z gfs keeps the trend going, and is a couple degrees colder

[Ntxw]

18z gfs keeps the trend going, and is a couple degrees colder

18z GFS would be a significant event.

[Haris]

The GFS, ECMWF, and ICON ensemble means continue to show no freezes for Austin through the end of their runs.

The GFS ensemble mean has barely freezing temperatures (30°) for lows in Dallas this coming weekend but no freezes thereafter. It also forecasts 0.20 inches of sleet/snow this weekend, but with air temperatures no lower than 30° and very warm soil temperatures, the impacts would be mainly on elevated roads. The GFS operational is colder but totally dry for this weekend, as is the ECMWF operational.

I would not 6 days out really advise using an ensembles' average low definitively for a forecast. It is just an average of the various scenarios. Sure, it maybe only 30 or 31, but it could be 39 or 19! NAM and operations will be way more preferred if indeed a cold front looks to come. Too early to make specific calls

[Ntxw]

Looks like another set up winter storm threat 7-8th but that's even further out. There's only been flash hints of that one, but hey as quickly as this closer one ramped up. Who knows? That's some wild swings out in the Pacific.

[Cerlin]

Looks like another set up winter storm threat 7-8th but that's even further out. There's only been flash hints of that one, but hey as quickly as this closer one ramped up. Who knows? That's some wild swings out in the Pacific.

That’s what’s intriguing me about the January setup. Models are showing the New Year’s storm but I’ve also seen decent support for a set up on the 7th/8th and the 12th/13th too..multiple chances so even if one fizzles out, we still have the potential for a different one!

[cheezyWXguy]

Looks like another set up winter storm threat 7-8th but that's even further out. There's only been flash hints of that one, but hey as quickly as this closer one ramped up. Who knows? That's some wild swings out in the Pacific.

Yeah looks interesting but the depicted pattern is wildly different than the 12z. Lots of turbulence in the models these days, but it’s better than consistently showing warm solutions like it used to.

This weekend’s setup reminds me a lot of January’s setup. Just hope it doesn’t trend too far south so that we can cash in up here this time.

[Iceresistance]

Looks like another set up winter storm threat 7-8th but that's even further out. There's only been flash hints of that one, but hey as quickly as this closer one ramped up. Who knows? That's some wild swings out in the Pacific.

That 2nd cold wave looks bigger too!

[Ntxw]

Looks like another set up winter storm threat 7-8th but that's even further out. There's only been flash hints of that one, but hey as quickly as this closer one ramped up. Who knows? That's some wild swings out in the Pacific.

Yeah looks interesting but the depicted pattern is wildly different than the 12z. Lots of turbulence in the models these days, but it’s better than consistently showing warm solutions like it used to.

This weekend’s setup reminds me a lot of January’s setup. Just hope it doesn’t trend too far south so that we can cash in up here this time.

At 500H pattern a lot is at stake with the N Pacific ridge. The good runs sends it poleward, the bad runs keep it in place. That's where a lot of the discrepancies lay.

Preferably we'd want it to shoot up to the Chuckchi/Alaska and then retrograde to Siberia and kick off a wave 1 event.

[bubba hotep]

[Iceresistance]

KFOR has a high of 20 with a 50% chance of snow on New Years Day


If I recall correctly, there was another winter storm that happened in 2020-2021, also known as the New Years Winter Storm of 2020-2021

[Ntxw]

Snippet from the FW AFD this afternoon.

.LONG TERM... /NEW/
/Tuesday Night through the Weekend/

The remainder of the workweek should be rather mundane to the
laity with continued warm weather under partly to mostly cloudy
skies. However, there will be a lot of interesting meteorology
ongoing. A weak cold front -- that functionally acts more like a
dryline given the negligible cold advection -- will be flirting
with the forecast area through Thursday. It should first approach
Tuesday (as mentioned above) and stall across the forecast area
overnight, roughly from Paris to Comanche. South flow just above
the surface will promote low-level isentropic ascent, helping to
develop isolated to scattered showers Tuesday night into Wednesday
morning over North Texas. The low-level flow aloft will veer
during the day, shunting a majority of the precip into East Texas.
Instability will be weak, but we can`t rule out an occasional
rumble or two of thunder.

The clinging front/dryline will lift back north to the Red River
by daybreak Wednesday, before moving east through the entire
forecast area Wednesday afternoon, effectively ending our precip
chances and drying things out a bit through Thursday. The front
will stall just to the south of our forecast area before lifting
north, again, as a warm front Thursday night into Friday.

The warm front should eventually stall near the Red River and
attach to a deepening surface low near the Panhandles Friday
night/Saturday morning. Meanwhile, a cold and deep upper trough
will overspread the Southern Plains and enhance frontogenetic
forcing near the stalled warm front. This should help develop
scattered to widespread showers over far North Texas Friday night
with most rain occurring generally east of I-35. As the upper
trough ejects east, it will drive a strong cold front south late
Saturday. A dryline, which will likely precede the cold frontal
passage, may develop additional showers/thunderstorms over the
eastern parts of the forecast area Saturday afternoon. At this
time range, it`s too soon to know if the dryline will convect
and/or how strong the potential storms would be.

Much cooler temperatures and gusty north winds will trail behind
the cold front Saturday night into Sunday. The upper trough should
lag behind the cold frontal passage by several hours, and the
timing and depth of this trough will prove consequential to the
sensible weather forecast. If the upper trough remains progressive
and largely attached to the mean flow, all precip should end by
the time temperatures become cool enough to support wintry precip.
If the upper trough`s vorticity maximum becomes detached and is
slower, then there is a good chance of snow across North Texas
Saturday night and Sunday morning. We did not include the mention
of snow in the official forecast at the moment since calibrated
NBM precip-type probabilities are less than 15%. We will have to
closely monitor the evolution of the upper trough passage over the
next couple days since temperatures will likely be cold enough to
support snow.

Speaking of cold temperatures, we are projecting everyone in the
forecast area to drop below freezing both Saturday night and
Sunday night. We are not anticipating a hard freeze, but many
north of I-20 should drop into the upper teens/lower 20s both
nights, with areas across Central Texas falling into the upper 20s
Sunday night. It would be a good idea to turn off your sprinkler
systems and protect any exposed outdoor plumbing that may freeze.
The cold temperatures shouldn`t last long as the high shifts east
and another strong ridge builds over the central/southwest CONUS
next week.

Bonnette

&&

.AVIATION... /Issued 1256 PM CST Mon Dec 27 2021/
/18z TAFs/

[Golf7270]

Snippet from the FW AFD this afternoon.

.LONG TERM... /NEW/
/Tuesday Night through the Weekend/

The remainder of the workweek should be rather mundane to the
laity with continued warm weather under partly to mostly cloudy
skies. However, there will be a lot of interesting meteorology
ongoing. A weak cold front -- that functionally acts more like a
dryline given the negligible cold advection -- will be flirting
with the forecast area through Thursday. It should first approach
Tuesday (as mentioned above) and stall across the forecast area
overnight, roughly from Paris to Comanche. South flow just above
the surface will promote low-level isentropic ascent, helping to
develop isolated to scattered showers Tuesday night into Wednesday
morning over North Texas. The low-level flow aloft will veer
during the day, shunting a majority of the precip into East Texas.
Instability will be weak, but we can`t rule out an occasional
rumble or two of thunder.

The clinging front/dryline will lift back north to the Red River
by daybreak Wednesday, before moving east through the entire
forecast area Wednesday afternoon, effectively ending our precip
chances and drying things out a bit through Thursday. The front
will stall just to the south of our forecast area before lifting
north, again, as a warm front Thursday night into Friday.

The warm front should eventually stall near the Red River and
attach to a deepening surface low near the Panhandles Friday
night/Saturday morning. Meanwhile, a cold and deep upper trough
will overspread the Southern Plains and enhance frontogenetic
forcing near the stalled warm front. This should help develop
scattered to widespread showers over far North Texas Friday night
with most rain occurring generally east of I-35. As the upper
trough ejects east, it will drive a strong cold front south late
Saturday. A dryline, which will likely precede the cold frontal
passage, may develop additional showers/thunderstorms over the
eastern parts of the forecast area Saturday afternoon. At this
time range, it`s too soon to know if the dryline will convect
and/or how strong the potential storms would be.

Much cooler temperatures and gusty north winds will trail behind
the cold front Saturday night into Sunday. The upper trough should
lag behind the cold frontal passage by several hours, and the
timing and depth of this trough will prove consequential to the
sensible weather forecast. If the upper trough remains progressive
and largely attached to the mean flow, all precip should end by
the time temperatures become cool enough to support wintry precip.
If the upper trough`s vorticity maximum becomes detached and is
slower, then there is a good chance of snow across North Texas
Saturday night and Sunday morning. We did not include the mention
of snow in the official forecast at the moment since calibrated
NBM precip-type probabilities are less than 15%. We will have to
closely monitor the evolution of the upper trough passage over the
next couple days since temperatures will likely be cold enough to
support snow.

Speaking of cold temperatures, we are projecting everyone in the
forecast area to drop below freezing both Saturday night and
Sunday night. We are not anticipating a hard freeze, but many
north of I-20 should drop into the upper teens/lower 20s both
nights, with areas across Central Texas falling into the upper 20s
Sunday night. It would be a good idea to turn off your sprinkler
systems and protect any exposed outdoor plumbing that may freeze.
The cold temperatures shouldn`t last long as the high shifts east
and another strong ridge builds over the central/southwest CONUS
next week.

Bonnette

&&

.AVIATION... /Issued 1256 PM CST Mon Dec 27 2021/
/18z TAFs/

Is there any model you favor over the other right now based on the pattern or is it literally not sure type scenario?

[Ntxw]

Is there any model you favor over the other right now based on the pattern or is it literally not sure type scenario?

In the medium to long range I like the EPS suite, it's done okay. I'd favor the poleward ridge -> Aleutian trough because I still think the MJO will deliver, it's just been slow. The recent GFS/GEFS shift to the Euro suite in the North Pacific helps with some confidence.

[Ntxw]

Lets also not forget with the recent weeks and months clash between very cold and very warm air masses is possible severe weather event. If the upper trough is negative tilt we might see some severe storms outbreak along the gulf coast.

[Ntxw]

I would not 6 days out really advise using an ensembles' average low definitively for a forecast. It is just an average of the various scenarios. Sure, it maybe only 30 or 31, but it could be 39 or 19! NAM and operations will be way more preferred if indeed a cold front looks to come. Too early to make specific calls

Ensembles are a great tool to clean up some muddied solutions but they are not be all end all. I'd definitely have more 'faith' long range with ensembles but they too can be at fault. As you mention they cannot always decipher real world solutions as a blend when you're within closer range. Reality isn't a blend of different solutions, one result wins. Example below, which is clearly going to be a failure.

0z Weds forecast for 18z the 2nd of January. Torch.



It isn't going to torch on the 2nd now in closer range. Quite the opposite.



There's nuances in there such as cold overpowering the upper flow.

[Cpv17]

Could we see the beginning of a warming trend on the models again as we get into the midrange like we usually do? Latest GFS might be showing that for southeast TX. Definitely not as cold as the 12z.

[harp]

Could we see the beginning of a warming trend on the models again as we get into the midrange like we usually do? Latest GFS might be showing that for southeast TX. Definitely not as cold as the 12z.

Huh? Did you see the second front?

[Ntxw]

Could we see the beginning of a warming trend on the models again as we get into the midrange like we usually do? Latest GFS might be showing that for southeast TX. Definitely not as cold as the 12z.

I think it's possible. If you're talking about this weekend yeah, the stronger the ULL trends the more warm air it pumps ahead of it. A weaker dry, positive tilted trough is better for driving cold.

[Cpv17]

Could we see the beginning of a warming trend on the models again as we get into the midrange like we usually do? Latest GFS might be showing that for southeast TX. Definitely not as cold as the 12z.

Huh? Did you see the second front?

I’m talking about this weekends front. Temps are about 3 degrees warmer compared to 12z.