January 2021 Medium/Longterm Pattern Discussion.

[jaxjagman]

Control today almost looks like it wants  to just blow up the SPV

[jaxjagman]

Looks like a potential active period coming up maybe.The MJO tho being shown into the the COD into the IO there looks like some decent convection more into the MARITIME,also into Jan you can clearly see a KW possibly into ,BETWEEN JAN 4-6,tho this certainly could change.

[John1122]

Hi-res GFS crush job out West.  Regular GFS is a severe ice storm too. Memphis just stays at 31 for a long time with freezing rain.  The Canadian is a a little further West and just makes a glacier in Texas, Oklahoma and Arkansas. 

[jaxjagman]

12 minutes ago, John1122 said:

Hi-res GFS crush job out West.  Regular GFS is a severe ice storm too. Memphis just stays at 31 for a long time with freezing rain.  The Canadian is a a little further West and just makes a glacier in Texas, Oklahoma and Arkansas. 

They havent had a good snow strorm in years

[John1122]

5 minutes ago, jaxjagman said:

They havent had a good snow strorm in years

I'd love to see West and Middle areas get a big winter storm this season.  The ice they probably don't want. Some of the ice scenarios showing up rignt now would be crippling to the power grid. 

[jaxjagman]

2 minutes ago, John1122 said:

I'd love to see West and Middle areas get a big winter storm this season.  The ice they probably don't want. Some of the ice scenarios showing up rignt now would be crippling to the power grid. 

In 2016 in a NINA the models kept showing a big storm in this area but we ended up with one of our best snow storms on record,no clue if it will happen again.Its so weird how the Valley works,someone is always going to be left out one way or another

[Save the itchy algae!]

I have a hard time believing the trajectory of the New Years storm as it relates to the 6z gfs.  It’s too far west to be a cutter and too far east to be a 4 corners low.  It has to go much further west or east.  What does it want to be?  We’ll see I suppose but I’m certain it’s not going to go due north from the tx/la coast all the way to Chicago.

[AMZ8990]

9 hours ago, John1122 said:

I'd love to see West and Middle areas get a big winter storm this season.  The ice they probably don't want. Some of the ice scenarios showing up rignt now would be crippling to the power grid. 

Definitely don’t want any ice if we can help it.  I think me and Jax would gladly take a few inches of the white stuff though.  Maybe we will get lucky this week

[AMZ8990]

15 hours ago, John1122 said:

GFS shifted towards the Euro that run.  Might have a thread called "AMZ's New Years Rockin Eve" or something like that if the west shifts can stop now.

I like the sound of that!!  Haha

[Carvers Gap]

A warm to very warm pattern is beginning to show up  in the medium to long range ensembles, and beginning by midweek of this week.  The 12z EPS has moved the eastern ridge flip to this Tuesday w one slp passing through it afterwards.  The eastern ridge will likely get stronger during the next 7-10 days.   This is the time of year when the EPS begins to rule the roost, but is not infallible either.  It does provide some relief around d14 with a ridge redeveloping out West.  We saw a similar look last year.  As with this last year, the cold air supply will be likely lacking.  My confidence is increasing that we are about to enter at least a two week time from from from say Dec30-Jan15 of AN to much AN temps w a seasonal day or two thrown in.  After that, comes the game we have played for the last two winters....waiting for the pattern to come back.  Is this trough out West a pattern relaxation or a new pattern.  Don't know, but I do know that trough has been tough to move (during the past two winters) once in place regardless of EPO ridges(tucks under that ridge) and SSW events.  The -NAO looks to be a consistent feature, but connects with the eastern ridge.   There are signs this current pattern could return during the second half of January, but if I had a dime for every time I said that during the past two years, I would be a wealthy man.  The MJO this morning is now forecast to go into phase three and likely four(with a warm tour likely), and I wouldn't be surprised to see it loop back through those phases once finished...the OLR maps show very little movement from the phase 3-4 regions.  The MJO is now driving the bus, though the -NAO does sit in the passenger seat.  I think the greater concern is that NA is going to be completely devoid of cold air for the foreseeable future.  Now, it can still snow in a warm pattern, but is much more difficult.  This year would be a possibility for exactly that with the -NAO in place and storms tracking south.   The wild card which I hate to depend upon for cold weather  is the strat warm.  Yet again, it has fouled what looked like was a nice pattern on the horizon in modeling.  Right now we are either looking at a potential pattern change to an eastern ridge/western trough or a long relaxation of the December pattern which was decent(not exceptional but decent).   During the next 2-3 days, if we are still looking at the western ridge holding in the d14-16 range on the EPS, then we know the drill.  So, hopefully (and I have low expectations for this)...we see the western ridge pop mid-month and the -NAO holds(there is some evidence in LR modeling that it may be leaving the playing field later in January according to the 6z CFSv2 run) - if so that is cold pattern IF cold air can be supplied to NA.   (The once strongly forecast -NAO for the end of this month - it is positive today on the CPC site.). Maybe we can steal a storm in a warm pattern coming up.  Last note, when the SSW hit in 2018, modeling flipped from warm to cold in one, single run for March.  I am not holding my breath on that one, but that is on the table as an option.  For now the SSW looks to impact East Asia and Western Europe.   That could change.  

So January thaw or pattern change?  That is the real question for me.

[Holston_River_Rambler]

So, I went to the SSWE Compendium Index (https://csl.noaa.gov/groups/csl8/sswcompendium/majorevents.html) and looked for all SSWE that occurred in La Ninas and between mid Dec and early Feb. 

There were six that matched those criteria. Before I post what I found, the overall implications are, IMO,  not very helpful for figuring out how this one will go. The events of early Jan 1971 and early Jan 1985 look like they had the best outcome, if we are looking for a storm. The AMO was negative then, so those events may not have much bearing on how this one will play out. If the past four during the positive AMO (mid Dec. 1998; early Feb 2001; mid Jan 2006; late Jan 2009) are any indication, what we are probably looking at is some changes to high latitude blocking approximately 10 - 20 days after the event, and then a return to the base state a couple of weeks later. 

Here are images and gifs of the strat at the event as documented in the Index mentioned above, a gif of the H5 and MSLP patterns around the time of the SSWE and then around two weeks later, when changes to high latitude pattern became evident. Every event featured changes to the heights at high latitudes, but to me, it's unclear exactly how the SSWE is implicated (if at all) in those changes. In. other words, I'm not sure how much of those changes were just normal pattern evolution and how much they were connected to a SSWE. 

Apologies for the blinky images in some of the gifs. The NCEP reanalysis panels load a little slowly, so just doing a screen recording was the best way to get the max number of images to get a sense for the flow of the pattern before and after. 

Jan 1971:

 

Pattern before:

 

Pattern After:

 

 

Jan 1985:

 

 

Pattern before:

 

Pattern after:

 

 

Dec 1998:

 

 

Pattern before:

 

Pattern after:

 

 

Feb 2001:

 

Pattern before:

 

Pattern after:

 

 

Jan 2006:

 

Pattern before:

 

Pattern after:

 

Jan 2009:

 

Pattern before:

 

Pattern after:

 

 

I thought I'd look at the MJO too, by looking for precip. anomalies in the tropics.. No real surprises there, since all the above were La Ninas:

 

Still not sure what I make of all this, but here it is, as a reference point, as we go forward. 

@John1122 any data for storms/ temps in some of those windows? 

[Carvers Gap]

Interesting stuff, Holston.   January 1985 in terms of cold is what March 1993 is in terms of storms for NE TN.  It is the Holy Grail of winter patterns.   I think right now this is a very different era in terms of weather.  Not sure the usual analogs apply - and that could be good or bad.  We will see.  Certainly not going to complain if the weather goes that direction.   Will be tough to reverse the temps AN anomalies for the first two weeks of January I think.  The one possible good scenario which I mentioned a few days ago(and this AM), is that if the cold were to dump into that trough forecast mid-month, that would be a well-timed strat split.  SSWs in my experience are just terribly tough to predict.  Truly hate that we are substituting what looked like a decent pattern for a flat unknown(leaning warm) pattern. "IF" this is going to be in our favor, we should begin to see that on modeling quite soon.  The past couple of SSWs have resulted in cold dumping into the Rockies after a head fake eastward.  Second half of the month of January would be our chance.  My bigger concern is there is very little cold on this side of the hemisphere to even tap should the SSW behave favorably - takes some time to resupply Canada.   I do think we are likely at least one more cold shot that would be a good winter storm window, even if the pattern flips to a western trough.  Very much looks like the West is about to get winter after a quiet month in December which followed a great November there.  

@Holston_River_Rambler, see what you think about February 2010.   If I was going with a glass half full attitude, that would be my choice in terms of similarities.  Very similar in terms of set-up - even had a late December snow in NE TN.

[Carvers Gap]

January 2019 would be the other (glass half empty) SSW.  I "think" both of those winters had some La Nina characteristics(both Feb10, and Jan19).  2019 did have an SSW event - debatable what it did to the TPV. I did go back and check this morning on the site below about 2019.  That was the January that had a great look and went to pot due to the SSW(maybe partial or mostly unsuccessful split...think that split had small twin vortices at the TPV off the top of my head but the main vortex held)

https://csl.noaa.gov/groups/csl8/sswcompendium/

 

[Carvers Gap]

Here is the paper on the SSW for January 2019.  Dig through it.  I can barley understand about half of it.  However, one can see the split in early January of at least one of the vortices into twin vortices.  Have to go running.  I have not read all of it.  Will be chewing on that for a while.  Seems to me there are similarities in both the Feb'10 and Jan'19 events.  Looks like the 2019 did indeed split the 2019 SPV.

http://s2sprediction.net/file/documents_publications/2019JD030826.pdf

[Carvers Gap]

The 2019 split was right around the development of an El Nino.  It seems that El Nino failed to couple immediately with the atmosphere IMO as evidenced by the Nina-eque conditions that would be had the following winter  - which was last winter.   IMHO, we finally had Nino conditions from that event just this past summer and those lasted into December of this year despite the Nina.  So, that 2019 event might be a decent counterbalance to the Feb'10 event - those would be my two choices and they give a wide range of "good" and "bad" outcomes.

[nrgjeff]

That went to the dogs in a hurry. 3 of the last 4 times I've posed bullish hope the last couple seasons it's gone mild within 36 hours. Jinx is real.

On 12/24/2020 at 3:21 PM, nrgjeff said:

Nice timing! Strato Warming has apparently ingested into the just released ECMWF weekly charts. I approve that message!

Greenland block remains stout for 3-4 weeks. Some ridging West Coast. North Pac trough is more Bering sea than Alaska, a bullish shift for here.

Surface Deep South is blue. Tennessee Valley and Mid South is variable. However these next four weeks are the core of January. We take!

I'll be off for a few days. Merry Christmas!

Maybe after Martin Luther King Day. Hopefully then it's not maybe Feb. Then maybe Valentines Day. Then maybe next year.

Some past set-ups where Greenland blocking was in conflict with Pacific mild going into early January, Europe and Asia got more cold dumps than North America. When North America starts out fairly mild it's tough. We'll see though. Time will tell.

[Daniel Boone]

Alot of oddities in the Weather these days. There was a time when A pretty much equalled B as far as cause and effect.  As with the Gl block, War linkage. Used 2 b a rarity to almost non existent in the cold Season. Not anymore it appears.

       Could be the Atlantic warm phase. Alot of variables working in conjunction . Warmer overal NH.  If we could get a consistent 50-50 low, that linkage wouldn't occur. Those ssts off NF could be partial culprit to that missing piece. 

[Holston_River_Rambler]

The more I think about it, the more I think the SSWE mess is just a roll of the dice, with those dice slightly weighted to fall in the favor of Eurasia. Not really anything we didn't already know, if we start with that premise and go forward. Not sure I really profited from all that gif making and analogue looking earlier this AM. Maybe I'll feel differently later though. I guess I do see some things to watch out for as it unfolds:

1) Watch the tropical convection. If it does indeed set up in the MC and the SSWE helps fuel it by cooling the upper parts of the troposphere, that would be bad. If however, it gets going more in the Western Pac, that would be good. 

2) It will probably take 10 - 20 days for any High latitude blocking to happen, once the SSWE event occurs, and models will likely struggle a lot. 

I guess the problem I'm having with this, is I could have just taken out the strat. stuff and made the same statements above, and they would have been equally valid: 

1) watch tropical convection

2) models will struggle with blocky scenarios. 

 

1 hour ago, Carvers Gap said:

 Looks like the 2019 did indeed split the 2019 SPV.

http://s2sprediction.net/file/documents_publications/2019JD030826.pdf

Thank you for the link to that, I think it will be helpful for me to try and figure out how to look for the signs of SSWE future. Seems to me, and I may be reading it incorrectly, that it is geared more toward subseasonal predictability of the SSWE in NWP, rather than the atmospheric repercussions once they happen. 

[Holston_River_Rambler]

Of course this could all just be the same pattern we've dealt with already this winter. Extended looks bad for a bit (esp. Pacific), then improves as things get closer in time. Or La Nina could be starting to flex more. That image griteater posted yesterday of the last months OLR average was pretty damning. 

 

 

[Holston_River_Rambler]

May be time for our annual monsoon to pick up:

[Carvers Gap]

Cause you know like clockwork, the 12z GFS is going to go stone cold after I make a post about a warm-up - at least it is sort of in the time frame that was discussed.  LOL.  I actually don't mind unpredictability.  I just don't like warm patterns which lock into place.

[Carvers Gap]

12z Euro - Western Atlantic Ridge City.

[PowellVolz]

12z Euro - Western Atlantic Ridge City.

Bermuda high?


.

[Carvers Gap]

45 minutes ago, PowellVolz said:

Bermuda high?


.

Basically the NAO connects or extends into a ridge that stretches from lower latitudes into the Arctic.  Normally, that is something one sees during the summer.  As Boone noted, that is a fairly fair feature during winter.  It is likely the mechanism that will split the TPV.  When I see it during SSWs, I always think "torch."  But you can almost take it to the bank the an SSW is under way (or about to be when you see the monster).

[Carvers Gap]

1 hour ago, Holston_River_Rambler said:

The more I think about it, the more I think the SSWE mess is just a roll of the dice, with those dice slightly weighted to fall in the favor of Eurasia. Not really anything we didn't already know, if we start with that premise and go forward. Not sure I really profited from all that gif making and analogue looking earlier this AM. Maybe I'll feel differently later though. I guess I do see some things to watch out for as it unfolds:

1) Watch the tropical convection. If it does indeed set up in the MC and the SSWE helps fuel it by cooling the upper parts of the troposphere, that would be bad. If however, it gets going more in the Western Pac, that would be good. 

2) It will probably take 10 - 20 days for any High latitude blocking to happen, once the SSWE event occurs, and models will likely struggle a lot. 

I guess the problem I'm having with this, is I could have just taken out the strat. stuff and made the same statements above, and they would have been equally valid: 

1) watch tropical convection

2) models will struggle with blocky scenarios. 

 

Thank you for the link to that, I think it will be helpful for me to try and figure out how to look for the signs of SSWE future. Seems to me, and I may be reading it incorrectly, that it is geared more toward subseasonal predictability of the SSWE in NWP, rather than the atmospheric repercussions once they happen. 

I wouldn't give up on your cold shot just yet.  A little help from the PAC, and things would get interesting just after the 12z EPS run.  The thing to watch now is how the EPS corrects now that it wants a trough in the East late in its run.  Won't take much to take the d10-15 look on the EPS and make it better...and won't take much to make it worse.  LOL.  What is the phrase from last week?  Living on the edge!  This is your cold shot if it happens!  Again, I like 09-10 and 18-19 as SSW events.  09-10 Turned out pretty well I think.  Having that -NAO and -AO up there is to our benefit with the SSW.

[Daniel Boone]

What we hope happens here is once the SSW Affects are underway the HLB will be strongly entrenched and the WAR will gradually erode sw to Ne,  and allow troughs to undercut into the SE. Neg. tilted troughs can really dump on us snowwise.

[Carvers Gap]

@Holston_River_Rambler, the 18z GEFS and GFS support your idea that we are going to see cold.  The 18z CFSv2 does as well.  The GEFS extended is meh, but it ran on an earlier run today I think.  So, trends this afternoon have been quickly to a more favorable solution.  Maybe those ensembles are "feeling" the strat split now?  You may be on to something.

[Carvers Gap]

21 hours ago, jaxjagman said:

Looks like a potential active period coming up maybe.The MJO tho being shown into the the COD into the IO there looks like some decent convection more into the MARITIME,also into Jan you can clearly see a KW possibly into ,BETWEEN JAN 4-6,tho this certainly could change.

I think we are going to be fighting the MJO the rest of the way - very much agree.  Hoping this strat split and high latitude blocking will provide some balance this year.  I liked where the 18z GEFS went.  Really hope that holds.  

[Carvers Gap]

Also, for TRI folks...I noticed that MRX is mentioning patching freezing drizzle in the AM.  Just a heads up.

[Carvers Gap]

Just spitballing....One thought I had this morning is that we are long overdue for a stretch of winters with -NAO/Atlantic blocking.  If we could hit such a stretch, that gives us many more scenarios towards better winters and could offset MJO problems.  The Pacific is defiantly a more consistent driver for cold when it is favorable.  However, the Atlantic is saving our tails this winter.  I fully believe this winter would have been very warm had the NAO not flipped negative unexpectedly.  The NAO deal is likey tied to the AMO being in a warm phase for us...but maybe this(a stretch of NAO winters) is kind of a run-op or a cue that it is about to flip during the upcoming years.