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Winter 2020-2021


ORH_wxman
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11 minutes ago, 40/70 Benchmark said:

2004-2005 was not a neg NAO winter going by CPC, nor have I ever known it to be one. March 2005 was very negative, but Feb was near neutral and Dec and Januaru were ++.

2002-2003 was pretty neutral...even a hair +.

2012 and 2009 def. work....not sure about '46. I'll take your word for it.

The study I did was based on the Hurrell SLP method (not CPC) and I used DJFM composite. Both methods have their flaws.

 

As for including March in the winter NAO calc, you can make a case either way....but I included it at the time since it's a massive part of our snowfall climo. I know I don't have to tell you how many times a big blocking episode in March produced some whopper months.

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4 minutes ago, ORH_wxman said:

The study I did was based on the Hurrell SLP method (not CPC) and I used DJFM composite. Both methods have their flaws.

 

As for including March in the winter NAO calc, you can make a case either way....but I included it at the time since it's a massive part of our snowfall climo. I know I don't have to tell you how many times a big blocking episode in March produced some whopper months.

 No. We agree on that, wholeheartedly. I am a big fan of including March in snowfall climo (sorry Kev) at our latitude. Its akin to excluding October from cane climo, which no one does.

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Purely anecdotal ( ...though my convictions are "observationally" rooted - lol ..) but I don't see a useful correlation to the actual weather patterns is the thing...

Now ... obviously 'blocking' is a distinction of patternization ... But, when time is introduced, nah.  Not by frequency for either restoration and/or modulation tendencies when comparing Octobers to their ensuing DJF of any given year.  It's noise in other words...  30 days of noise in October "might" contain orientations that equal or bear some resemblance to fractals embedded in the noise of 90s days.  What happens to November in that - I mean...  it's like ( to me ) arbitrary when we start doing that... may as well compare April 13th's 6 years later to October 12th's ... aha!

Pointing out a rather obvious circumstantial concept:  30 days is long enough that a blip for a week, or even two weeks of October blocking(no blocking) may occur; but then 90 days is an even longer...thus, much more likely chance that either of those circumstances may be ephemerally observed - think about it this way ...  a progressive pattern tendency may go through a 'relaxation' - well, that relaxation by virtue of needing to go the other way to actually achieve relaxation may mean 5 days of transient -EPO(-AO)-NAO in there...or even two week's worth of it...before the the next 40 days of progressive winter ruining piece of shitness sets in...

What?  do we say that was a correlation because say, there was a typhoon over the western Pacific back on October 10 early that autumn that happened to recurve ...building a height response over the Aleutian Basin --> brief NW flow downstream over western Canada ? 

It's too much of a stretch to suggest those disparate moving parts have any kind of direct or even indirect causal connection ...  

So in simple terms ... yeah - "weak" puts it maybe even too strongly if you ask me.   

I think this is a simple matter of 'conditioning' ... Circumstantially, if there is a 100+ winter snow year, the antecedent autumn sticks out in memory ... because as part of the human condition, we seek and create patterns to describe everything we see in nature. It's why we discovered ( or invented - jury's still out on that..) mathematical rules, and language to convey the mechanics.  Add artistic expression to that...  it's all creating patterns from the nebularity of reality...  blah blah ...that's an infinitely deep well of philosophy ... But, on point, a big snow year happens rare enough, that the Octobers that preceded it offer an easy guess-vector.   But unfortunately, the age -old statistical argument of that not being a substantial enough data density to offer a high confidence ... screams at us.  

Top 20 years of snow and cold and ... winter cinema in general... is 20 Octobers - wooooh!    

20 Octobers out that last 300 million years since the break up of Pangea sent Europe and Africa sailing away to the east and created the distinction of eastern N/A...  

It doesn't automatically preclude the possible correlation useful, ... that is true. But the convention of using statistics, which "correlating" is ... And that requires that the entire course of discussion does not require anyone reading as much as I have typed over it just now... haha.  

But, they say there is a modest 'negative' ... okay -   maybe that is just because there are only a handful of years where the signal was just planetary scale, thus large and immovable and lapsed longer than typical pattern gestation...into the ensuing DJF. ..

I would almost suggest that aggregating Oct and Nov might have more statistical correlative just based on these weighting concepts -

 

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17 minutes ago, OSUmetstud said:

I hadn't appreciated that both the ECMWF and UKMET have a negative NAO in December, looks quite positive for Jan and Feb. 

 

Hadn't seen that, but makes perfect sense to me.

I will also add, that January and February don't exactly look like train wrecks in the depiction...NAO not withstanding. Cold source appears in tact, though I am needing to twist my head to angles that I shouldn't approaching 40. My guess is gradient city for JF. Maybe SNE and even perhaps N mid atl biased Dec, before CNE/NNE wears the crown for JF.

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2 minutes ago, ORH_wxman said:

I wish they had H5 instead of SLP, but that is def a -NAO for December....they all have an Aleutian ridge too which is not a surprise in a rapidly strengthening La Nina.

Hopefully we can get that ridge to be fairly wide, and poke poleward...its nuances like that that usually make or break a winter in a less than ideal regime overall.

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13 minutes ago, 40/70 Benchmark said:

Hopefully we can get that ridge to be fairly wide, and poke poleward...its nuances like that that usually make or break a winter in a less than ideal regime overall.

Yeah if you have a suppressed Aleutian ridge, then it risks a pig in AK. We narrowly avoided it in 2007-2008, but did not in 2011-2012.

'08-'09, and '10-'11 had very poleward Aleutian ridges....so did 2017-2018. 2016-2017 was moderately poleward.

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November 2019'S NAO averaged negative by a click and a half SD ... and then in the first week of Dec, as the index began modulating positive toward a December destined to a modest +.25 to .5 SD, ...it was right in there most of us acquired pretty much 70 or 80 % of our yearly snow ballast.  We seemed to double that in morning frosts through late March from that point forward. 

The rub on that was that said event was not 121" of snow - lol

But, the early and deep polar index ( NAO ) last year was off-set by the AO by a whole month.  Interestingly...according to CPC  

(   https://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/monthly.ao.index.b50.current.ascii.table ) the AO carved out a deep January, when the NAO was positive.  That's interesting... Because those two domains share/over-lap a consider amount of their geographical area, so having the AO manage a -1.5 SD while NAO was positive in change, ... that's really stressing the odds there...  The CDC's correlation table has the AO and NAO positively correlated by some .7 ...which for atmospheric phenomenon is quite indicative.  Yet, they found a mid winter butt bang status like (-1.5 SD AO)( +.5 NAO) ?    Just sort of cynically ... I'm inclined to think our misgivings about 2019-2020's winter as an entertainment gestalt might be related to that rareness...  EDIT this is wrong - I miss aligned the columns - sorry ugh. They were better matched afterall ... 

= December 2019 was doomed after that first week, but the month salvaged by virtue of actually having the first week's snow/storminess take place.   

So what I am getting at is an aside point along the way of this discussion; since the year 2000 ( as a notably observable trend) with either snow, or...patterns conducive to snow ( that latter may actually open up the totals to a bigger number but is subjectively debatable popsicle headaches stuff ) has been been recurrent themes in autumns.   

I see it unfolding in the GEFs/ tele's ...and the operational GFS ... yet again. The last cycle of GFS has 516 DM thickness across the NP on October 18!!!  That's just not normal...sorry... But, it may not happen? But the fact that the model keeps doing it...and, we have in fact almost all but grown accustomed to if not expecting our snow in October ( ludicrous by any imaginative standard prior to the year 2000) ...I think it's all connected.   

And it matters... because... the NAO blocking of November last year went on to NOT do shit for winter... It was not correlated to winter at all at least in that one shimmering example. Yet, the AO...which was positive in October and Nov aggregates, went demonstratively opposite.

It's not just noisy...it's a damn din and polar indexes in autumn were excessively negatively correlated in the one example last year. 

My most recent thought on this winter is a n-streamer ... 

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7 minutes ago, Typhoon Tip said:

The obvious ? 

that's a global warming depiction there ...when every single guidance source has an unbalanced warm/cool ratio ... that's a warming world - sorry. 

 

It doesn't look very realistic either....esp the ECMWF. It basically has almost no negative 5H anomalies. Scott and I have been wondering this for years....if that is why these models have trouble spitting out spatially representative anomalies. (i.e., we talked about years like 2014 and 2015 where they just refused to spit out downstream cold anomalies despite an EPO ridge from hell over AK/Yukon).

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2 hours ago, 40/70 Benchmark said:

I feel like the odds of a ratter have decreased from a month ago...for us, anyway.

...Since you asked me and care so very deeply how my opinion affects you and all ...

I think this could be an N-stream dominated winter, but one that wends its way to (climate signal + average cold)/2 = ... take a f'in guess how that parlays snow...

it's like a N-stream dominate winter superimposed over a planetary hockey-stick (denying ...) climate modality that doesn't end well for winter enthusiasts ... oh, not for decades. Okay, as we know in climate science, it doesn't move on a predictable slope though.  

I'm starting to wonder if might cross over a threshold ... years before Will's take on things that a 'no winter scenario' here won't set into until beyond the visible universe of our life spans -- how? because we arrogantly ( as human tendency ) keep expecting a slower deal merely because our egos get in the way of the fact that just because we can't imagine horror unfolding tomorrow, that means it can't happen. But, threshold happen by breaking at stress points...  and boom!  as they say in Ebonics, 'we be f'ed'  

Not to be alarming or nothin' but Mad Max's setting was the year 2021 muah hahahaha.   

The U.N. isn't holding back today ...  'the earth will become an uninhabitable hell to millions' .. 

Somewhere between those two futures lurks the inevitability smearing of our Currier&Ives portrait of winters - 

...maybe

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4 minutes ago, ORH_wxman said:

It doesn't look very realistic either....esp the ECMWF. It basically has almost no negative 5H anomalies. Scott and I have been wondering this for years....if that is why these models have trouble spitting out spatially representative anomalies. (i.e., we talked about years like 2014 and 2015 where they just refused to spit out downstream cold anomalies despite an EPO ridge from hell over AK/Yukon).

it's too much - sure... Glad you picked up on the sarcasm - tough to deliver that ...

I do think the world is warming and I do fear thresholds and so forth but come on - look how the models took the planet of Venus and crash-landed it into the Pacific Basin ...it's like minus 10 SD La Nina which is outside the theoretical bounds of Terrain physics or something  ahahaha

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21 minutes ago, Typhoon Tip said:

...Since you asked me and care so very deeply how my opinion affects you and all ...

I think this could be an N-stream dominated winter, but one that wends its way to (climate signal + average cold)/2 = ... take a f'in guess how that parlays snow...

it's like a N-stream dominate winter superimposed over a planetary hockey-stick (denying ...) climate modality that doesn't end well for winter enthusiasts ... oh, not for decades. Okay, as we know in climate science, it doesn't move on a predictable slope though.  

I'm starting to wonder if might cross over a threshold ... years before Will's take on things that a 'no winter scenario' here won't set into until beyond the visible universe of our life spans -- how? because we arrogantly keep expecting a slower deal merely because our egos get in the way of the fact that just because we can't imagine horror unfolding tomorrow, that means it can't happen. But, threshold happen by breaking at stress points...  and boom!  as they say in Ebonics, 'we be f'ed'  

Not to be alarming or nothin' but Mad Max's setting was the year 2021 muah hahahaha.   

The U.N. isn't holding back today ...  'the earth will become an uninhabitable hell to millions' .. 

Somewhere between those two futures lurks the inevitability smearing of our Currier&Ives portrait of winters - 

...maybe

We get it....it will  never snow again because of the incredible expanding Hadley Cell. lol

I agree with you regarding N Stream dominance...

 

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7 hours ago, 40/70 Benchmark said:

I don't think it changes much. I think it just increases confidence that it will not be a very cold winter in the east...especially south of 40N. I think it also augments the importance of the polar fields this season. I am not sold on a strong la nina by a long shot,  though....frankly, I am surprised that it looks to make moderate considering where we were a month ago.

Yea, I kinda figured strong Niñas probably didn’t differ much from moderate Niñas. I think moderate is pretty much a given now, I think there’s a possibility that it may go strong, but not a super event like the UKMET is showing with a trimonthly of < -2C

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9 minutes ago, CoastalWx said:

Some of those looked pretty good to me? Stout Aleutian ridge and at times into AK ridge with a cold Canada. Some of those had heights BN right near the US border. That would definitely have some cold to hopefully tap. 

Yeah the ncep version looked pretty solid most of the winter. Euro was hideous after a decent December. 

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