January Medium/Long Range Disco Thread

[Maestrobjwa]

1 minute ago, cbmclean said:

I stole this graphic from the post that PSU made to start off the snow climo thread last year.  He has marked the EPO domain.  An EPO ridge is just AN 500 MB heights in the EPO region.

 

Now on those maps you guys post...above normal heights are shown in red?

[cbmclean]

Just now, Maestrobjwa said:

Now on those maps you guys post...above normal heights are shown in red?

I don't post many maps.  I am actually a novice myself, but I love to learn.  Yes on those 500 MB maps the AN anomalies are various shades of red.

[psuhoffman]

4 minutes ago, Maestrobjwa said:

Now on those maps you guys post...above normal heights are shown in red?

Yes...and this is what he was talking about. Get a ridge into the EPO (AK region) and it sends cold continental air down east of the Rockies into the central and eastern US. 

[thunderman]

Not much change that I can see at a quick glance of the GFS and Canadian for the New Years event.

Canadian zr QPF eye candy for extreme western zones:

[Round Hill WX]

Initially, this -NAO is a bootleg. Typically it can help tap cold continental Canadian air. Right now the cold air is on the other side of the NH. Here is the result. Gonna probably have to wait. 

[Amped]

Maybe it'll trend east

 

[midatlanticweather]

 

[psuhoffman]

@WxUSAF tonight’s op gfs I think is more indicative of what the ensembles are “seeing” then the bootleg heights issue.  From 300-340 there is a full Rex block centered near the southern tip of Baffin with a 50/50 trapped doing loops under it. If anything that should be too much blocking. And yet it rains to Montreal during that period. There is no cold. The flow is blocked. The systems shear out. 
 

However...that is the first major longwave trough after the block retrogrades.  Imo, like you said, if the blocking persists I think each subsequent wave will likely have a bit more cold to work with. The euro weekly ensembles, however, never quite get to that critical tipping point where there is enough depth of cold to keep storms from either waiting and cutting or shearing out.  I agree that’s unlikely. But the gfs shows that it’s a “real” block...and still warm. 

[cbmclean]

20 minutes ago, psuhoffman said:

@WxUSAF tonight’s op gfs I think is more indicative of what the ensembles are “seeing” then the bootleg heights issue.  From 300-340 there is a full Rex block centered near the southern tip of Baffin with a 50/50 trapped doing loops under it. If anything that should be too much blocking. And yet it rains to Montreal during that period. There is no cold. The flow is blocked. The systems shear out. 
 

However...that is the first major longwave trough after the block retrogrades.  Imo, like you said, if the blocking persists I think each subsequent wave will likely have a bit more cold to work with. The euro weekly ensembles, however, never quite get to that critical tipping point where there is enough depth of cold to keep storms from either waiting and cutting or shearing out.  I agree that’s unlikely. But the gfs shows that it’s a “real” block...and still warm. 

You have mentioned that you don't feel as if super cold cross-polar flow is in the cards this year.  What is your feeling about the feasibility of simply getting the Pacific to be mediocre enough to not overpower perfect NAO blocking?

[psuhoffman]

41 minutes ago, cbmclean said:

You have mentioned that you don't feel as if super cold cross-polar flow is in the cards this year.  What is your feeling about the feasibility of simply getting the Pacific to be mediocre enough to not overpower perfect NAO blocking?

I’m optimistic. We will see. 

[howrdcounty snow]

Mild Conditions May Prevail Across Much of U.S. for First Three Months of 2021

The Weather Channel - December 16, 2020 Temperatures across much of the United States will be milder than average for the remainder of winter and into the start of spring, according to the latest outlook issued by The Weather Company, an IBM Business.

[yoda]

Wow

https://mobile.twitter.com/webberweather/status/1343835393028927489

[yoda]

Sounds like Webb is in the snow train

https://mobile.twitter.com/webberweather/status/1343831117162545155

https://mobile.twitter.com/webberweather/status/1343682463546175494

https://mobile.twitter.com/webberweather/status/1343646568474406915

[yoda]

Webb also tweeted about "the pattern is x amount if days away therefore bullcrap" crowd too

https://mobile.twitter.com/webberweather/status/1343651365709619211

[yoda]

Excellent and very detailed thread by HM (Anthony Masiello) about SSW and upcoming pattern for rest of winter through analog perspective 

https://mobile.twitter.com/antmasiello/status/1343822175892074496

[CAPE]

4 hours ago, cbmclean said:

You have mentioned that you don't feel as if super cold cross-polar flow is in the cards this year.  What is your feeling about the feasibility of simply getting the Pacific to be mediocre enough to not overpower perfect NAO blocking?

The LR ensembles are suggesting some improvement in the EPAC, with the trough weakening some/retrograding, and a developing EPO ridge. That would provide a mechanism to redirect the flow, and inject some colder air. This seems to be the way things are evolving, but it will likely take some time. I can see some folks getting impatient because there will likely be a favorable west-based block for a time, without necessarily seeing more favorable outcomes. The evolution of the SWE probably increases the uncertainty on ultimate longwave pattern evolution, and how much colder we get going forward. It appears that the -AO/NAO will have persistence, so that's one big box checked on the list for winter weather in this region.

[aldie 22]

1 hour ago, yoda said:

Excellent and very detailed thread by HM (Anthony Masiello) about SSW and upcoming pattern for rest of winter through analog perspective 

https://mobile.twitter.com/antmasiello/status/1343822175892074496

The part I read said the cold usually lags 20-30 days 

[aldie 22]

Anything before January 20th in our region will be gravy....after that I remain hopeful

[Ralph Wiggum]

6 minutes ago, leesburg 04 said:

Anything before January 20th in our region will be gravy....after that I remain hopeful

January of which year? 2022?

I've never seen guidance track so many ull and surface lows to our South and yield rain to SE Canada during prime climo with such a distinct west-based NAO in my 30 years of tracking. New Englanders must be jumping from bridges. At least we are used to regularly failing down this way.

[aldie 22]

3 minutes ago, Ralph Wiggum said:

January of which year? 2022?

I've never seen guidance track so many ull and surface lows to our South and yield rain to SE Canada during prime climo with such a distinct west-based NAO in my 30 years of tracking. New Englanders must be jumping from bridges. At least we are used to regularly failing down this way.

They're complaining pretty hard up there, lots of words like bootleg etc. Who knows....I guess we will see...it's almost Spring anyway

[40westwx]

7 hours ago, Amped said:

Maybe it'll trend east

 

 

yeah it is disgusting over their.. I have been begging my wife to hop on a plane to portland and go to mount bachelor for the weekend.. but you know.. Corona.. 

[CAPE]

Extended GEFS has the look we need to flush the Pac puke and inject legit cold into our source region. Hopefully we get there, but it will take some time.

eta- h5 is actually much improved out west by mid Jan, but still relatively mild in the lower levels at that time.

[BristowWx]

We'll get something wintry with that GEFS look.  Won't likely be cold smoke but we don't see that much anyway.  couple of 1-3 or 2-4 inch slop fest events would do nicely.  

[CAPE]

Just now, BristowWx said:

We'll get something wintry with that GEFS look.  Won't likely be cold smoke but we don't see that much anyway.  couple of 1-3 or 2-4 inch slop fest events would do nicely.  

I would trade that look with a much more favorable Pac and less blocking for what the models are advertising over the next 10 days or so.

[frd]

8 minutes ago, CAPE said:

Extended GEFS has the look we need to flush the Pac puke and inject legit cold into our source region. Hopefully we get there, but it will take some time.

eta- h5 is actually much improved out west by mid Jan, but still relatively mild in the lower levels at that time.

Looking at 500 certainly makes you think that NA gets the benefits of the SSWE. And speculation would suggest the cold air continues to gather and deepen past this time frame.  

Also,  some off the climo charts possibilities exist down the road, with the incredible low pressure storm system in the North Pac and a possible world breaking high pressure reading yesterday.    

[poolz1]

1 minute ago, CAPE said:

I would trade that look with a much more favorable Pac and less blocking for what the models are advertising over the next 10 days or so.

Nice to see some panels that do not show a ridge in the 50/50 region.  Interesting that weeklies show heights lowering in that area around the same timeframe....wk 2/3.  

GEFS starting the second week in Jan...repetitive 50/50 lows and a more traditional -NAO look.  Really hope we dont have to kick this can! 

[CAPE]

Looking at 50 mb and 500 mb height/temp anomalies on the LR GEFS would imply strat-trop coupling and a favorable environment for continued HL blocking.

[Ralph Wiggum]

25 minutes ago, CAPE said:

I would trade that look with a much more favorable Pac and less blocking for what the models are advertising over the next 10 days or so.

So we've moved on from the -NAO and are now cheering for a +PNA / better PAC instead? If it means getting the key ingredient (cold air) down to our region, then sign me up....I think. But you know once we get that look we are going cold and dry.

[CAPE]

1 minute ago, Ralph Wiggum said:

So we've moved on from the -NAO and are now cheering for a +PNA / better PAC instead? If it means getting the key ingredient (cold air) down to our region, then sign me up....I think. But you know once we get that look we are going cold and dry.

The -NAO with a horrid Pac isn't likely to make many people happy, so..

The other interesting thing with the advertised +heights over Baffin in the LR- and this is being debated in the NE forum- is that it may be the result of mild Pac air flow across Canada, warming and expanding the column, and producing those anomalous 500 mb heights, vs an actual ridge(anticyclone) which should have an adjacent trough over the east. I am not sure if I buy that, but there doesn't seem to be much curvature to the height lines once the +heights move into the sweet spot. I think that is probably more an artifact of a smoothed mean 15 days out. Either way, the PAC needs to become less hostile going forward or we will likely continue to struggle for chances of frozen.

[aldie 22]

5 minutes ago, CAPE said:

The -NAO with a horrid Pac isn't likely to make many people happy, so..

The other interesting thing with the advertised +heights over Baffin in the LR- and this is being debated in the NE forum- is that it may be the result of mild Pac air flow across Canada, warming and expanding the column, and producing those anomalous 500 mb heights, vs an actual ridge(anticyclone) which should have an adjacent trough over the east. I am not sure if I buy that, but there doesn't seem to be much curvature to the height lines once the +heights move into the sweet spot. I think that is probably more an artifact of a smoothed mean 15 days out. Either way, the PAC needs to become less hostile going forward or we will likely continue to struggle for chances of frozen.

bootleg