Texas Winter 2020-2021

[cheezyWXguy]

This will be a nice surprise if it pans out, but I don’t think this is THE event of the season. GFS has periodically shown other events in the long range, and seems to show a good number of systems moving through. One of these has got to do it, right?

[Ntxw]

This will be a nice surprise if it pans out, but I don’t think this is THE event of the season. GFS has periodically shown other events in the long range, and seems to show a good number of systems moving through. One of these has got to do it, right?

If the ducks line up right, I think this could be the IT storm for the I-35 corridor. A track like what could potentially happen is really rare for one to dig so far south and then head north/northeast through Texas as a snow event.

We see a ton of neutral and positive tilt systems (they often go negative either to our north or east). There are only a handful of systems that have taken such a track and are often in the history books as notable. You see something like "2 feet in Waco", "a foot in Victoria" etc.

[Cerlin]

This event will very much depend on the freezing line, as it will for sure include a changeover from rain to snow. If the ULL continues to deepen like it does on the CMC, then a changeover will be pretty quick and result in some accumulations. If it stays shallower, it might be a longer time of a wintry mix which might completely change what accumulation potential there is.

[bubba hotep]

A couple of things of note on the 12z GFS, the air mass over the top is not very cold and the system wraps in some pretty warm air, since it dives so far south. So on the GFS DFW is above freezing with a warm layer aloft. That isn't really a great setup for snow but some time to work this out.

ETA: The 12z CMC is much colder than the GFS and is a classic snow storm for DFW.

[orangeblood]

This will be a nice surprise if it pans out, but I don’t think this is THE event of the season. GFS has periodically shown other events in the long range, and seems to show a good number of systems moving through. One of these has got to do it, right?

If the ducks line up right, I think this could be the IT storm for the I-35 corridor. A track like what could potentially happen is really rare for one to dig so far south and then head north/northeast through Texas as a snow event.

Yep, our crazy uncle is showing the perfect Upper Level trajectory for a North Texas winter storm....rain, sleet to moderate wrap around snow as the ULL pulls off to the NE

[bubba hotep]

A couple of things of note on the 12z GFS, the air mass over the top is not very cold and the system wraps in some pretty warm air, since it dives so far south. So on the GFS DFW is above freezing with a warm layer aloft. That isn't really a great setup for snow but some time to work this out.

ETA: The 12z CMC is much colder than the GFS and is a classic snow storm for DFW.

There are a few ways to look at this but one thing that seems to stand out is the flow over the Midwest.

The 12z GFS has a bit of ridging across this area as the ULL has cutoff over Northern Mexico.



The 12z CMC has the opposite, giving our system better access to the deeper cold air.



I don't have this map for the CMC but the GFS has a very thin streamer coming down, typically we would like to see this thicker. If we could produce this same map for the CMC then I would guess that we would see a thick streamer indicating a colder column down the backside of our system.



The 12z GFS is close and a big improvement over the 12z yesterday but we still need to see some improvement in temps up the column over DFW.

[bubba hotep]

If you don't have your coffee stained copy available then you need to print this out and study it http://nwafiles.nwas.org/digest/papers/ ... 7-Ryan.pdf as we track our this system this week.

[Cpv17]

Still need a good amount of improvement in the models before I start buying in. Euro up next.

[bubba hotep]

Through 72hrs the 12z Euro appears to be splitting the difference b/w the CMC and GFS. Not seeing any major differences, so maybe the models are coming into agreement on a final solution? Still about 24hrs until our system moves onshore, so there are still some data gaps out there.

[gboudx]

Waiting for 57 to pop in and crush this.

[Brent]

Euro has the heaviest snow just west and NW of DFW but this would still be a significant snowstorm for lately

[Haris]

UKIE

[Ntxw]

Euro has the heaviest snow just west and NW of DFW but this would still be a significant snowstorm for lately

https://i.ibb.co/XzkP5kR/sn10-acc-us-sc-8.png

We're all watching for upper level improvement. We're getting in the range where every model run is going to be scrutinized. At some point the discussion will be track of the snow axis. Some runs/models go east some go west...oh the joy of that .

[Ntxw]

Through 72hrs the 12z Euro appears to be splitting the difference b/w the CMC and GFS. Not seeing any major differences, so maybe the models are coming into agreement on a final solution? Still about 24hrs until our system moves onshore, so there are still some data gaps out there.

The broad pattern is pretty good agreement with the major players. This is the best snow threat we've had since March 2015. Seasonal favorability of the -AO/-NAO paying off.

If we can get the cold upper levels a little sooner this will really be a huge ticket, something like Christmas Eve 09 but further south and east. A lot of IFs in these sentences.

[bubba hotep]

Through 72hrs the 12z Euro appears to be splitting the difference b/w the CMC and GFS. Not seeing any major differences, so maybe the models are coming into agreement on a final solution? Still about 24hrs until our system moves onshore, so there are still some data gaps out there.

The broad pattern is pretty good agreement with the major players. This is the best snow threat we've had since March 2015. Seasonal favorability of the -AO/-NAO paying off.

If we can get the cold upper levels a little sooner this will really be a huge ticket, something like Christmas Eve 09 but further south and east. A lot of IFs in these sentences.

The track and orientation of our system is going to bounce around a lot shifting the axis of heaviest snow around. One way to decrease the influence of that would be to get more cold air in place, qpf won't be an issue. Need to watch the northern stream s/w that I highlighted earlier. Things that could swing in our favor - stronger thus dumping down more cold in advance of our system or slower (CMC solution) allowing system a direct tap.

[bubba hotep]

Euro has the heaviest snow just west and NW of DFW but this would still be a significant snowstorm for lately

https://i.ibb.co/XzkP5kR/sn10-acc-us-sc-8.png

Blend this with that UKMet snow map

[rwfromkansas]

A blend of the Euro and UK...that’s a snowgasm for DFW.

[Ntxw]

Side stepping..

The ensembles have had the look of retrograding the Atlantic blocking closer to the Davis strait/Northeastern Canada so we'll likely see some more threats the first 2 weeks of January. We've had an unusual start to winter so far regarding the blocking episode. Winter 2020-2021 keeps coming back to the blocks over the far North Atlantic there which has forced storms to deepen as they cross Texas. There hasn't been sustained winter blocking there since 2009-2011 years. We've just lacked the cold air so far. Oklahoma scored a few weeks ago a couple of times.

This is weird since we are in La Nina but in a changing Pacific climate who knows anymore..

[rwfromkansas]

Larry Cosgrove hasn’t said much but that he’s leaning more toward sleet with a little snow at end right now. Hopefully can get some deeper cold.

[Brent]

I don't know if anyone saw Steve McCauley's post on Facebook but he seems to think someone around here will have a real snow