December 2021 Medium/Long Range Discussion Thread

[CAPE]

34 minutes ago, SnowenOutThere said:

Euro looking less amped as the low is in the north central U.S. but goes south and has snow for the d.c area at 105.

From what I can see on the free site it looks like a coating to an inch for most of the area east of the highlands.

Given climo, trajectory of the approaching shortwave/lack of moisture, seeing flakes fall in the lowlands would be a win. It would take more dig and surface low development sooner/ closer to the coast to get something more significant.

[nw baltimore wx]

58 minutes ago, CAPE said:

From what I can see on the free site it looks like a coating to an inch for most of the area east of the highlands.

Given climo, trajectory of the approaching shortwave/lack of moisture, seeing flakes fall in the lowlands would be a win. It would take more dig and surface low development sooner/ closer to the coast to get something more significant.

Putting up Christmas decorations, Sunday football on the tv, and snow falling would make me very happy.

[Weather Will]

I will take the appetizer this weekend, and a main course next….(WB 6z GFS).

[nj2va]

29 minutes ago, nw baltimore wx said:

Putting up Christmas decorations, Sunday football on the tv, and snow falling would make me very happy.

Any snow is good around these parts….and its doubly good when its during the Christmas season.  

[BristowWx]

I've seen more digital snow this year than all of last winter...and its only Nov....this can't be good

[wxdude64]

36 minutes ago, Weather Will said:

I will take the appetizer this weekend, and a main course next….

Dec 5th...lock it in!

[Weather Will]

Last year, the MJO did not cooperate….this year maybe phase 7 by the  end of the first week of December can’t hurt our chances for some cold and stormy weather as others have been saying. 

[Wonderdog]

17 minutes ago, BristowWx said:

I've seen more digital snow this year than all of last winter...and its only Nov....this can't be good

I was thinking the same thing. Early December looks to have a few shots of cold air to come through the area. Might be a good opportunity to score early.

[BristowWx]

10 minutes ago, Wonderdog said:

I was thinking the same thing. Early December looks to have a few shots of cold air to come through the area. Might be a good opportunity to score early.

I guess we will just go with it...enjoy the ride...I have learned its not worth the stress of looking too long range.  I did that for thanksgiving this year...looked ahead two weeks ago...looked digitally awesome for storminess on the models...and here we are

[SnowenOutThere]

Imagine the OBS thread for this as people wait for the rain snow line.

[mattie g]

8 minutes ago, SnowenOutThere said:

Imagine the OBS thread for this as people wait for the rain snow line.

Trailing waves always work out for us, so I’m sure we’d all be quite confident going into it.

[MillvilleWx]

11 hours ago, WxUSAF said:

@MillvilleWx at the party

 

12 hours ago, WinterWxLuvr said:

You don’t realize it, obviously, but our snow is more important than your coworker.

I love you guys 

Settling into work. Pretty mundane out here today. Will look at stuff this morning and give you guys a scoop. 

[WeatherShak]

Putting up Christmas decorations, Sunday football on the tv, and snow falling would make me very happy.

Was thinking the same thing. Snow TV would be great for a lot of folks mood.

[MillvilleWx]

Alright guys, took a look at a few things this morning with regards to the November system. I will not be entertaining the December 5th storm for awhile yet, although that is a very favorable time frame considering history around these parts. No rhyme or reason to it, but Dec 5th is just a great period for winter last 20 years. 

Anyways, a couple things I noticed off the bat that show the distinct differences in outcomes for the region, and a lot can be deduced from 5H on both the Euro and GFS.

 

Taking a look at some highlighted areas, there are two areas to watch. The first is the obvious s/w digging through the Great Lakes and interacting with a s/w piece that ejects from the Tenn Valley. Notice here the interaction already taking place as the s/w over WI digs quickly and starts to catch up to the southern stream vort. There's a bit of enhancement of the southern wave with greater difluent pattern over western VA into DC/MD. This is why the GFS has entertained the greater potential for snow because the dynamics are favorable as the mean s/w pattern presents some PVA traversing the area, allowing for ascent to be maximized at this time frame over the Mid Atlantic hood. The second area of note is the ridge axis out west and the accompanying stream of s/w's entering British Columbia. This is important as the ridge axis is favorable in both amplitude and orientation. This is why the later frames show a capture at 5H and generate a closed low over the Delmarva before scooting off the NJ coast. As long as this remains favorable, the area can score some flakes. If the ridge pumps further, the s/w over WI would likely gain more favorable amplitude and the threat for more snow is possible. But, there's also the other way, which is kind of what the Euro wants to imply.

Now lets look at the 00z Euro run for the same time frame. Notice the orientation of the ridge out west AND the amplitude being less prolific? Well, you can thank a more powerful s/w disturbance causing a flattening of the ridge over BC which would have downstream implications for the Mid Atlantic. The two eastern s/w's are present, but the flow is not meridional, it's more zonal as you head Tenn Valley on east. This causes the energy over WI/MI to not dig as far south as necessary to really cash in on the better dynamics, leading to weaker ascent over the area with less southern coverage of precip. Now, there is some snow for part of the area, but it's confined to I-70 on north as the energy does provide some PVA for a time and we cash on what ascent is necessary. The key is having the ridge out west better aligned over ID and the s/w's entering BC to be held back or less amplified. This is certainly possible, but something to monitor. 

The last piece circled over the Canadian Maritimes is the previous low that bombs over Nova Scotia and would favor a better chance for the pattern to be less progressive and keep the energy driving out of Canada at play. So far, both models are similar in that regard, but you would absolutely want that in the picture. If that goes, might be a tough trickier to get a favorable amplitude on the digging mean trough east of the Mississippi. 

That's all I got. I'll be chiming in, when I can the next succession of days.

[WxUSAF]

Overnight EPS and GEFS both are cankicking/muting the early December torch somewhat. Both show another trough digging in around Dec 4-5, which is when there probably will be a big storm somewhere in the eastern CONUS. Given the look, I’m skeptical that it’s a snowy pattern for us, although the trailing wave idea can work in otherwise crappy patterns. 

[psuhoffman]

43 minutes ago, WxUSAF said:

Overnight EPS and GEFS both are cankicking/muting the early December torch somewhat. Both show another trough digging in around Dec 4-5, which is when there probably will be a big storm somewhere in the eastern CONUS. Given the look, I’m skeptical that it’s a snowy pattern for us, although the trailing wave idea can work in otherwise crappy patterns. 

It looks generally seasonably variable. But if the Mjo wants to take its time so that we get an actual favorable pattern later in December I’m ok with that. 

[LP08]

ICON delivers Sunday into monday with the heaviest stripe of snow through EZF...

[ldub23]

Another JB storm coming. He was the first to say Dec would be  cold and snowy.

 

[NorthArlington101]

4 minutes ago, LP08 said:

ICON delivers Sunday into monday with the heaviest stripe of snow through EZF...

This is basically banter, so apologies, but I'd pay an obscene amount of money to move this up a day and get some snow falling during the UVA/Virginia Tech football game. Only thing that could make UVA routing Tech better is if it was a snow game... 

To end the banter, snowmap!

[LP08]

1 minute ago, NorthArlington101 said:

This is basically banter, so apologies, but I'd pay an obscene amount of money to move this up a day and get some snow falling during the UVA/Virginia Tech football game. Only thing that could make UVA routing Tech better is if it was a snow game... 

To end the banter, snowmap!

We are a basketball school now (the bolded)

 

....but yes that was a nice change from its 6z run and showed the progression that @MillvilleWx was showing earlier.

[NorthArlington101]

12z GFS doesn't look like it's gonna do it for us by hr99 -- vort seems to be too north/lot less strong than in 06z, just flipping back and forth.

very light snow for parts of the area at 102.

[LP08]

Backside vort out of Canada is slower to dive in the backside of the trough, definitely not as good as 6z on the GFS.

[midatlanticweather]

1 minute ago, NorthArlington101 said:

12z GFS doesn't look like it's gonna do it for us by hr99 -- vort seems to be too north/lot less strong than in 06z, just flipping back and forth.

very light snow for parts of the area at 102.

Typical craptastic! This is such a small feature I just would like to see some flakes. May not get even that

 

 

[WxUSAF]

30 minutes ago, psuhoffman said:

It looks generally seasonably variable. But if the Mjo wants to take its time so that we get an actual favorable pattern later in December I’m ok with that. 

Same. Would much rather have a favorable longwave pattern later into December when climo temps are colder.

[IronTy]

31 minutes ago, ldub23 said:

Another JB storm coming. He was the first to say Dec would be  cold and snowy.

 

JB is the first to forecast that any month of the year is going to be cold and snowy.  I hope he's right this time.  Is he calling this one Winter Storm Brandon?

[Winter Wizard]

GFS shifts well north with the vort, so it's a congrats Mount Washington. 

[WxUSAF]

31 minutes ago, ldub23 said:

Another JB storm coming. He was the first to say Dec would be  cold and snowy.

 

Another? When did I miss the first one?

[Stormfly]

Those models are such teasers.  There might as well be an armada of helicopters dropping frozen wieners down everywhere!

[Eskimo Joe]

2 minutes ago, WxUSAF said:

Another? When did I miss the first one?

Yesterday. Millions affected. Holidays ruined. Worst storm since 2020.

[IronTy]

Just now, Stormfly said:

Those models are such teasers.  There might as well be an armada of helicopters dropping frozen wieners down everywhere!

Maybe it's confirmation bias but it seems like there is ALWAYS a MA snowstorm in the ~240hr range on the models.  Is there some sort of technical reason for this?  Like some sort of amplification or feedback that is inherently built into the models?  Anybody have a clue?