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January 2021 General Discussions & Observations Thread


Stormlover74
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Don/Walt/Allsnow/Bluewave

Wouldn't the look below be a gradient look with the SE Ridge and Negative NAO? If so, with the cold leaking into the SW US, couldn't that be an VERY snowy and icy look for us? I know 2014 is an analog year which we were in the colder side of the gradient.

I feel that the look below is far better than what we have now.

Please correct me if I am wrong I do not want to mislead the board and give false optimism.

Thanks

image.png.83974252efbab0fa5058b133df8a34a2.png

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2 minutes ago, EastonSN+ said:

Don/Walt/Allsnow/Bluewave

Wouldn't the look below be a gradient look with the SE Ridge and Negative NAO? If so, with the cold leaking into the SW US, couldn't that be an VERY snowy and icy look for us? I know 2014 is an analog year which we were in the colder side of the gradient.

I feel that the look below is far better than what we have now.

Please correct me if I am wrong I do not want to mislead the board and give false optimism.

Thanks

image.png.83974252efbab0fa5058b133df8a34a2.png

You don’t have a -epo on that map so it won’t be as cold. That’s a cutter / overrunning map with artic highs in Canada. The nao might help suppress the southeast ridge 

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2 minutes ago, EastonSN+ said:

Don/Walt/Allsnow/Bluewave

Wouldn't the look below be a gradient look with the SE Ridge and Negative NAO? If so, with the cold leaking into the SW US, couldn't that be an VERY snowy and icy look for us? I know 2014 is an analog year which we were in the colder side of the gradient.

I feel that the look below is far better than what we have now.

Please correct me if I am wrong I do not want to mislead the board and give false optimism.

Thanks

image.png.83974252efbab0fa5058b133df8a34a2.png

2014 had a severely negative EPO and a severely positive PDO, neither of which we are going to have. It also did not have a solidly moderate La Niña like we have now. It also featured an extremely positive NAO and AO

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7 minutes ago, Allsnow said:

You don’t have a -epo on that map so it won’t be as cold. That’s a cutter / overrunning map with artic highs in Canada. The nao might help suppress the southeast ridge 

Unreal. I am still 0.5 inches less snow than last year. Can't believe I can still end up with a worse winter that last year.

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8 minutes ago, snowman19 said:

2014 had a severely negative EPO and a severely positive PDO, neither of which we are going to have. It also did not have a solidly moderate La Niña like we have now. It also featured an extremely positive NAO and AO

I guess our only hope in that pattern is for the NAO to be negative enough to suppress the SE Ridge.

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36 minutes ago, MJO812 said:

Trusting the long range for any type of weather isn't a good idea. 

People keep bringing up the stupid ssw and get excited. That never works out well for our area. 

The pacific rules over everything

If that even happens 

That’s an important point about the sudden stratospheric warming event (SSW).

With the polar vortex splitting, Eurasia was favored for the severe cold. That’s, by far, the most common case, as displacement events favor North America. The Twitter accounts reflexively proclaiming that the stratospheric warming meant that severe cold would pour into the region have little understanding of such events and their implications. That’s the fact. One sees their track record with stratospheric warmings over and over again, including forecasts for such events that never develop, because they focus solely on one specific layer of the stratosphere (either 30 mb or 10 mb) not all layers. 

There was potential for a snowy but not overly cold pattern here, but favorable 500 mb patterns don’t amount to much without surface features. That’s why potential isn’t always realized. We’ll have to see if this is the case again during the second half of January where there will be potential (somewhat favorable to favorable upper air pattern).

I’m not ready to write things off for the second half of January just yet. But when the AO goes positive and/or the PNA goes negative, then the window of opportunity will close. For January, the AO-/PNA+ pattern is the most favorable for significant (6” or above) snowstorms for the Philadelphia and New York City areas.

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27 minutes ago, EastonSN+ said:

Don/Walt/Allsnow/Bluewave

Wouldn't the look below be a gradient look with the SE Ridge and Negative NAO? If so, with the cold leaking into the SW US, couldn't that be an VERY snowy and icy look for us? I know 2014 is an analog year which we were in the colder side of the gradient.

I feel that the look below is far better than what we have now.

Please correct me if I am wrong I do not want to mislead the board and give false optimism.

Thanks

image.png.83974252efbab0fa5058b133df8a34a2.png

Gradient patterns can produce. But I don’t like this pattern currently shown at the end of the EPS for a number of reasons:

1. Gradient patterns that produce a lot of snow typically have a trough all across Canada

2. There is a lot of cold not marginal air available to be tapped in eastern Canada

The February 1994 500 mb pattern provides a classic example of the kind of gradient patterns that work. The forecast one does not resemble that pattern.The North American trough is north-south oriented, not east-west oriented across Canada. The ridge in the southeast is more expansive and stronger.

If the pattern does, in fact, evolve toward that, I don’t believe we’ll see much snow until it changes again. Earlier runs of the EPS were better. Let’s see what the 12z cycle shows.

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10 minutes ago, donsutherland1 said:

That’s an important point about the sudden stratospheric warming event (SSW).

With the polar vortex splitting, Eurasia was favored for the severe cold. That’s, by far, the most common case, as displacement events favor North America. The Twitter accounts reflexively proclaiming that the stratospheric warming meant that severe cold would pour into the region have little understanding of such events and their implications. That’s the fact. One sees their track record with stratospheric warmings over and over again, including forecasts for such events that never develop, because they focus solely on one specific layer of the stratosphere (either 30 mb or 10 mb) not all layers. 

There was potential for a snowy but not overly cold pattern here, but favorable 500 mb patterns don’t amount to much without surface features. That’s why potential isn’t always realized. We’ll have to see if this is the case again during the second half of January where there will be potential (somewhat favorable to favorable upper air pattern).

I’m not ready to write things off for the second half of January just yet. But when the AO goes positive and/or the PNA goes negative, then the window of opportunity will close. For January, the AO-/PNA+ pattern is the most favorable for significant (6” or above) snowstorms for the Philadelphia and New York City areas.

Thanks Don.

What I have re-learned this year is the day 10 plus ensembles and of course the weeklies are boarderline useless. They all agreed on a favorable pattern that now either a. Looks to be VERY transient or b. May not occur at all.

IMO a terrible performance by LR guidance.

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1 minute ago, EastonSN+ said:

Thanks Don.

What I have re-learned this year is the day 10 plus ensembles and of course the weeklies are boarderline useless. They all agreed on a favorable pattern that now either a. Looks to be VERY transient or b. May not occur at all.

IMO a terrible performance by LR guidance.

A complex pattern evolution is underway. The SSW coupled with a reinvigorated moderate La Niña is a challenging environment where model skill scores are likely to be lower than typical. The weeklies beyond two weeks have little or no skill relative to climatology. 

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21 minutes ago, donsutherland1 said:

Gradient patterns can produce. But I don’t like this pattern currently shown at the end of the EPS for a number of reasons:

1. Gradient patterns that produce a lot of snow typically have a trough all across Canada

2. There is a lot of cold not marginal air available to be tapped in eastern Canada

The February 1994 500 mb pattern provides a classic example of the kind of gradient patterns that work. The forecast one does not resemble that pattern.The North American trough is north-south oriented, not east-west oriented across Canada. The ridge in the southeast is more expansive and stronger.

If the pattern does, in fact, evolve toward that, I don’t believe we’ll see much snow until it changes again. Earlier runs of the EPS were better. Let’s see what the 12z cycle shows.

This is what we want to see to be on the snowy side of the gradient 

07AE3606-C0DE-4AC9-935B-2D287C05F04F.png
Neutral to -pna

-epo

-nao

-ao

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10 minutes ago, bluewave said:

That’s why we need bias correction for our ensembles beyond 5 to 7 days. The models have been consistently underestimating the +EPO pattern. So if we correct for that, then the longer range guidance will have more skill.  I posted this chart courtesy of Bamwx at the end of December.

3A40FE30-0CE6-4D3D-B92E-781290BF8A7F.thumb.jpeg.6b1673176d6d3afb829d22a02dfcd5da.jpeg

We don’t need the epo if we get a nice poleward pac ridge. That pna spike before the 15th was enough to get nyc 10 inches of snow. 

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6 minutes ago, Allsnow said:

We don’t need the epo if we get a nice poleward pac ridge. That pna spike before the 15th was enough to get nyc 10 inches of snow. 

The only -EPO drop of the whole winter so far was a few days before the the snowstorm. So the +PNA and -AO couldn’t get the job done without the -EPO assist. This was when the strong block popped up over the pole. 
 

ftp://ftp.cdc.noaa.gov/Public/map/teleconnections/epo.reanalysis.t10trunc.1948-present.txt

2020 12 01   57.33
2020 12 02  -20.52
2020 12 03    1.92
2020 12 04   -3.55
2020 12 05   18.98
2020 12 06  113.53
2020 12 07  160.49
2020 12 08   91.29
2020 12 09   24.46
2020 12 10  -40.49
2020 12 11  -98.53
2020 12 12  -90.08
2020 12 13  -32.48
2020 12 14  -11.99
2020 12 15   48.80
2020 12 16  122.15
2020 12 17  153.25
2020 12 18  199.37
2020 12 19  250.26
2020 12 20  239.82
2020 12 21  120.24
2020 12 22   70.85
2020 12 23   58.12
2020 12 24   69.31
2020 12 25   92.27
2020 12 26   68.14
2020 12 27    3.10
2020 12 28   -1.63
2020 12 29   11.33
2020 12 30   61.32
2020 12 31   60.59
2021 01 01  127.22
2021 01 02  264.17
2021 01 03  296.05
2021 01 04  248.51
2021 01 05  260.79
2021 01 06  249.45
2021 01 07  137.72
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26 minutes ago, bluewave said:

The only -EPO drop of the whole winter so far was a few days before the the snowstorm. So the +PNA and -AO couldn’t get the job done without the -EPO assist. This was when the strong block popped up over the pole. 
 

ftp://ftp.cdc.noaa.gov/Public/map/teleconnections/epo.reanalysis.t10trunc.1948-present.txt


2020 12 01   57.33
2020 12 02  -20.52
2020 12 03    1.92
2020 12 04   -3.55
2020 12 05   18.98
2020 12 06  113.53
2020 12 07  160.49
2020 12 08   91.29
2020 12 09   24.46
2020 12 10  -40.49
2020 12 11  -98.53
2020 12 12  -90.08
2020 12 13  -32.48
2020 12 14  -11.99
2020 12 15   48.80
2020 12 16  122.15
2020 12 17  153.25
2020 12 18  199.37
2020 12 19  250.26
2020 12 20  239.82
2020 12 21  120.24
2020 12 22   70.85
2020 12 23   58.12
2020 12 24   69.31
2020 12 25   92.27
2020 12 26   68.14
2020 12 27    3.10
2020 12 28   -1.63
2020 12 29   11.33
2020 12 30   61.32
2020 12 31   60.59
2021 01 01  127.22
2021 01 02  264.17
2021 01 03  296.05
2021 01 04  248.51
2021 01 05  260.79
2021 01 06  249.45
2021 01 07  137.72

If we need a -epo to snow around here then we will avg 6-10 inches per winter. Give me a stout pna ridge over a epo 

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1 hour ago, Allsnow said:

If we need a -epo to snow around here then we will avg 6-10 inches per winter. Give me a stout pna ridge over a epo 

You have to look at it through the lens of the pattern that we have at the time. When we have a record breaking Pacific Jet pattern, we need all the help that we can get from Pacific blocking. So in the case this December, it took the poleward extension of the ridge through the EPO region to the North Pole to get us the snowstorm. But during other years with a less amped up Pacific Jet,  we have gotten by with just the +PNA and +EPO and -AO. That’s why the +EPO during El Niño’s can be OK. The North Pacific Jet weakens while the STJ becomes the strongest. This helps carve out the trough over the SE US and allows the 50/50 low and high over New England hold its ground  with a +EPO and weaker Pacific Jet. So +EPO during an El Niño isn’t the liability it can be with a La Niña. That’s why our best La Niña seasons like 95-96 had such frequent blocking near Alaska. While great El Niño’s had the STJ running the show with -AO and +PNA.

NYC 2 greatest snowstorms

27.5”....Jan 22-23 -16 super El Niño +EPO


2016 01 20   43.26
2016 01 21   31.89
2016 01 22   48.24
2016 01 23   71.40
2016 01 24   71.56
2016 01 25   14.98
2016 01 26   29.36
2016 01 27   55.70
2016 01 28  160.56
2016 01 29  177.26

 

26.9”.....Feb 11-12-06....La Niña  -EPO

2006 02 09  -53.06
2006 02 10  -93.77
2006 02 11  -74.28
2006 02 12  -35.51
2006 02 13  -69.84
2006 02 14 -214.72
2006 02 15 -288.49
2006 02 16 -309.34
2006 02 17 -330.28
2006 02 18 -298.10

 

Late November 95 into April 96 historic snowfall pattern for a La Niña


33CACCC4-4AAB-4E12-B384-AF4B5CB74865.gif.d4289af1a63c6a600a1f36580937a2bc.gif

 

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6 minutes ago, WestBabylonWeather said:

I’m no expert

literally just a snow weenie with an interest in winter weather

but perhaps the models are having trouble with the upcoming pattern since the vortex is supposed to split or whatever, I don’t think they have any idea what storms will occur yet. Have to wait until the pattern takes hold? 
 

I will be annoyed if we have another winter with below average snow though

 

 

here - you can hope this verifies

gfsp_mslp_pcpn_frzn_us_39.png

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5 minutes ago, WestBabylonWeather said:

I’m no expert

literally just a snow weenie with an interest in winter weather

but perhaps the models are having trouble with the upcoming pattern since the vortex is supposed to split or whatever, I don’t think they have any idea what storms will occur yet. Have to wait until the pattern takes hold? 
 

I will be annoyed if we have another winter with below average snow though

 

 

When you came out of a decade where almost all the years were above average to much above average snowfall, what exactly do you expect to happen to reestablish the average? 

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3 minutes ago, Jeff Grann said:

When you came out of a decade where almost all the years were above average to much above average snowfall, what exactly do you expect to happen to reestablish the average? 

its January 9th and we are still above average this season - no one here has a clue how much total snowfall we will end up with this season...........we still have 3 months of potential remaining

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3 hours ago, bluewave said:

That’s why we need bias correction for our ensembles beyond 5 to 7 days. The models have been consistently underestimating the +EPO pattern. So if we correct for that, then the longer range guidance will have more skill.  I posted this chart courtesy of Bamwx at the end of December.

3A40FE30-0CE6-4D3D-B92E-781290BF8A7F.thumb.jpeg.6b1673176d6d3afb829d22a02dfcd5da.jpeg

The -EPO bias has been very severe for years now with all models, in particular the GEFS. The GEFS will insist on -EPO blocking run after run and won’t let it go until the last second, meanwhile the EPS and GEPS already figured out it wasn’t happening 10 runs earlier and dropped it. It’s been the GEFS’s MO for several winters in a row now, they’ve all been pretty horrible with that bias 

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27 minutes ago, NEG NAO said:

its January 9th and we are still above average this season - no one here has a clue how much total snowfall we will end up with this season...........we still have 3 months of potential remaining

I really don't understand how people can't grasp this concept. I have 19 inches so far this season IMBY and most people are average or above to date. We just don't know how the rest of the season is going to play out. The weather has been boring but it hasn't been a torch by any stretch. It's 32 and cloudy by me today. Lets just see how the next 2 months deliver. 

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1 hour ago, bluewave said:

We probably shouldn’t be too surprised by the models becoming less favorable than they were several days ago. There was a pretty impressive pattern reversal following the mid-December snowstorm. It was followed by the big warm up in late December and milder than average temperatures continuing right into January. It isn’t always that easy to return back to a snowy pattern once it reverses. Last winter was looking promising on the models until they saw the reversal in mid-December. NYC picked up some early December cold and snow. There was the record snowstorm in November 2018 and the cold lingered into mid-December before the pattern flipped. 

Models still look fine for a colder and possible stories pattern starting next weekend.

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4 hours ago, bluewave said:

You have to look at it through the lens of the pattern that we have at the time. When we have a record breaking Pacific Jet pattern, we need all the help that we can get from Pacific blocking. So in the case this December, it took the poleward extension of the ridge through the EPO region to the North Pole to get us the snowstorm. But during other years with a less amped up Pacific Jet,  we have gotten by with just the +PNA and +EPO and -AO. That’s why the +EPO during El Niño’s can be OK. The North Pacific Jet weakens while the STJ becomes the strongest. This helps carve out the trough over the SE US and allows the 50/50 low and high over New England hold its ground  with a +EPO and weaker Pacific Jet. So +EPO during an El Niño isn’t the liability it can be with a La Niña. That’s why our best La Niña seasons like 95-96 had such frequent blocking near Alaska. While great El Niño’s had the STJ running the show with -AO and +PNA.

NYC 2 greatest snowstorms

27.5”....Jan 22-23 -16 super El Niño +EPO


2016 01 20   43.26
2016 01 21   31.89
2016 01 22   48.24
2016 01 23   71.40
2016 01 24   71.56
2016 01 25   14.98
2016 01 26   29.36
2016 01 27   55.70
2016 01 28  160.56
2016 01 29  177.26


 

26.9”.....Feb 11-12-06....La Niña  -EPO


2006 02 09  -53.06
2006 02 10  -93.77
2006 02 11  -74.28
2006 02 12  -35.51
2006 02 13  -69.84
2006 02 14 -214.72
2006 02 15 -288.49
2006 02 16 -309.34
2006 02 17 -330.28
2006 02 18 -298.10

 

Late November 95 into April 96 historic snowfall pattern for a La Niña


33CACCC4-4AAB-4E12-B384-AF4B5CB74865.gif.d4289af1a63c6a600a1f36580937a2bc.gif

 

95-96 had a way better mjo then we have now 

A2A417F0-11B5-4591-920E-5790FEC8985E.gif

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