December 2022 Medium-Long Range Disco

[WxUSAF]

Just now, psuhoffman said:

Considering the time range and all the noise between now and then that needs sorting out, the Gfs was pretty close to the same solution as the cmc.
 

Yea I get that for many here the face one is wet and the other 2 feet of snow is lol but synoptically a slightly colder antecedent airmass in front, slightly less amplified primary, and the Gfs would have been the cmc solution. 

Yup. For whatever reason, the last 24-36 hours of Op runs have often wanted to phase in the PV to this event. Ensembles want nothing of the sort. 

[mattie g]

1 hour ago, SnowenOutThere said:

CMC says happy Christmas Eve Eve

Methinks someone saw the 12z CMC.

[Terpeast]

10 minutes ago, mattie g said:

Methinks someone saw the 12z CMC.

This depiction is what I think might happen if a cold disturbance runs over ripe warm waters off the MA coast… then BOOM. 

Not saying we’ll get a foot right here in DC. But someone up the corridor towards the NE is going to get hammered within a few weeks of this pattern. 

[Eskimo Joe]

A preview of the 850 temps on the GFS as we near Christmas

[brooklynwx99]

that system around the 23rd has been showing up on modeling for a while now, and it seems like the ensembles are beginning to parse the broad longwave features. with that said, there are actually a lot of pieces here, and they look like they can come together to produce some significant upside. at this point, it would be late December, and climo is much more favorable than it is now, even along the coast

1. this is the highly anomalous ridge that is going to form as a result of the +EAMT that is going to take place over the next several days. notice how this ridge extends and cuts off into the Beaufort Sea. this is important because it both establishes a very cold antecedent airmass, and it displaces the TPV, which I'll get to in a bit
2. this is the west-based -NAO blocking that forms as a result of this week's system. the Miller B that forms on Friday forces very warm air into the Davis Strait, which helps create a transient block that then decays over this region. this kind of decaying block over the Davis Strait is a precursor to some of our largest storms
3. this is the TPV that has been displaced by the ridging I talked about earlier. this serves to deliver very cold air to the NE US ahead of the potential storm, and it also plays a very important role in establishing confluent flow over SE Canada... it could act as a kind of 50/50 ULL, which is also why the block is so important. both of them work in tandem to deliver HP to SE Canada and prevent a cutter 
4. finally, this is the shortwave that is beginning to get picked out by modeling. this is a very vigorous signal for this far out, but it makes sense given the entire hemisphere forcing it into existence given the +EAMT and extension of the Pacific jet. this would roll off of the ridge and downstream into the confluent flow forced by the TPV and transient blocking

so, overall, there is a lot here to like. pretty much every piece is in place for a large-scale event around this time. now, there are obviously a lot of caveats at this range, as one would expect, and there is a possibility that something like the GFS OP plays out and it rains on everyone. I kind of have to favor inland regions, but that by no means rules anyone out

when I see this kind of longwave configuration, it does get me a bit excited. all of the pieces are in place, so we'll see how it plays out over the next week or so

[Eskimo Joe]

Thank you for the excellent write-up @brooklynwx99. Really appreciate your contributions.

[Chris78]

Great post @brooklynwx99

[mattie g]

17 minutes ago, Eskimo Joe said:

Thank you for the excellent write-up @brooklynwx99. Really appreciate your contributions.

 

15 minutes ago, Chris78 said:

Great post @brooklynwx99

What these guys said.

[WxUSAF]

Nice post @brooklynwx99! Having the ridge along the west coast vs slightly inland would normally favor a coastal runner or inland track. But the Atlantic side, with the PV well west of the canonical 50-50 location will fight against that. Long way out still, but with a very good airmass in place, I’d favor at least SOME frozen for everyone. Best chance at a white Christmas since 2010 without a doubt.

[Met1985]

19 minutes ago, brooklynwx99 said:

that system around the 23rd has been showing up on modeling for a while now, and it seems like the ensembles are beginning to parse the broad longwave features. with that said, there are actually a lot of pieces here, and they look like they can come together to produce some significant upside. at this point, it would be late December, and climo is much more favorable than it is now, even along the 

Excellent post as always! Even though I live in WNC your posts are always on point and thought provoking. 

[Ji]

Hi

[Wonderdog]

35 minutes ago, brooklynwx99 said:

that system around the 23rd has been showing up on modeling for a while now, and it seems like the ensembles are beginning to parse the broad longwave features. with that said, there are actually a lot of pieces here, and they look like they can come together to produce some significant upside. at this point, it would be late December, and climo is much more favorable than it is now, even along the coast

1. this is the highly anomalous ridge that is going to form as a result of the +EAMT that is going to take place over the next several days. notice how this ridge extends and cuts off into the Beaufort Sea. this is important because it both establishes a very cold antecedent airmass, and it displaces the TPV, which I'll get to in a bit
2. this is the west-based -NAO blocking that forms as a result of this week's system. the Miller B that forms on Friday forces very warm air into the Davis Strait, which helps create a transient block that then decays over this region. this kind of decaying block over the Davis Strait is a precursor to some of our largest storms
3. this is the TPV that has been displaced by the ridging I talked about earlier. this serves to deliver very cold air to the NE US ahead of the potential storm, and it also plays a very important role in establishing confluent flow over SE Canada... it could act as a kind of 50/50 ULL, which is also why the block is so important. both of them work in tandem to deliver HP to SE Canada and prevent a cutter 
4. finally, this is the shortwave that is beginning to get picked out by modeling. this is a very vigorous signal for this far out, but it makes sense given the entire hemisphere forcing it into existence given the +EAMT and extension of the Pacific jet. this would roll off of the ridge and downstream into the confluent flow forced by the TPV and transient blocking

so, overall, there is a lot here to like. pretty much every piece is in place for a large-scale event around this time. now, there are obviously a lot of caveats at this range, as one would expect, and there is a possibility that something like the GFS OP plays out and it rains on everyone. I kind of have to favor inland regions, but that by no means rules anyone out

when I see this kind of longwave configuration, it does get me a bit excited. all of the pieces are in place, so we'll see how it plays out over the next week or so

Any concerns that the ridge out west is too far west?

[Ji]

Any concerns that the ridge out west is too far west?

No concern at all

[Heisy]

Hi

Until the ridge is in a better position out west might as well close the shades. Hopefully it’s just euro overdoing things and blowing up storms in the LR.


.

[MN Transplant]

4 minutes ago, Ji said:

Hi

Matching 500

[brooklynwx99]

the ECMWF basically has the shortwave sit in one spot for days and doesn’t move it at all. absolutely weird stuff

i wouldn’t count on this happening. plays into the ECMWF’s overamplification bias as well. i think it broke this run LMAO

[Cobalt]

4 minutes ago, Ji said:

No concern at all

Just a small difference..

 

 

 

[Weather Will]

As I have been saying it will be a December to remember one way or the other!!!!

[RickinBaltimore]

Wow, that's quite a difference between the Euro and GFS. 

[Paleocene]

Yeah, let's wait for the EPS before we throw in the towel based on a day 10 euro op map.

[WxUSAF]

16 minutes ago, Heisy said:

Until the ridge is in a better position out west might as well close the shades. Hopefully it’s just euro overdoing things and blowing up storms in the LR.


.

Close the shades??  This is "close the shades"??  

 

I mean, are we only hunting for HECS here?  That ^^ is like a 9/10 look for snow chances for us. The VAST majority of our snow falls in a long wave pattern that is not a 10/10.   If we can only deal with 10/10 or we only get snow in 10/10 patterns, then it's time to move north or quit this hobby. 

[BristowWx]

^I think that op Euro run was a little jarring with people worried this is the first domino to fall or just a blip

[yoda]

12z EPS just a tad different than the Euro OP at Day 9 lol

 

 

 

[WxUSAF]

3 minutes ago, BristowWx said:

^I think that op Euro run was a little jarring with people worried this is the first domino to fall or just a blip

As I said earlier, the Op runs have been wanting to phase in the PV and make it dig deep in the Rockies over the last day or two.  Not sure why, but the ensemble means want nothing to do with that.  If that dichotomy continues through ~Sunday, then I'll start to get mildly concerned.

[ryanconway63]

can someone share the Euro EPS?

[SnowGolfBro]

Just now, yoda said:

12z EPS just a tad different than the Euro OP at Day 9 lol

 

 

 

We still need the proper level of panic and sacrifices to the Reaper to get a good snowstorm. Weenie Handbook 101

[anotherman]

Just now, ryanconway63 said:

can someone share the Euro EPS?

[CAPE]

33 minutes ago, Ji said:

Hi

Hi!

 

[WxUSAF]

2 minutes ago, anotherman said:

Looks disastrous.  Better pack it up and maybe we get lucky in March before spring arrives for good.  

[Buddy1987]

8 minutes ago, BristowWx said:

^I think that op Euro run was a little jarring with people worried this is the first domino to fall or just a blip

Yea I agree. @brooklynwx99 touched on the bias of over-amplifying but the Euro also has known biases when it comes to not ejecting systems out of the southwest and holding the energy back, thus imo why 500 and surface look the way they do based on what JI shared.