Winter 2021-2022

[snowman19]

1 hour ago, 40/70 Benchmark said:

Its central based, but I don't think structure is as important in a modest event....marginal ENSO events are a lot more variable due to less ENSO forcing...especially lately with the HC expansion, etc.

It’s central based for sure….however, if Coastalwx is right and this event goes low-end moderate….I would not want to be south of New England this winter

[CoastalWx]

52 minutes ago, George001 said:

The cfsv2 is not backing down at all, and is only increasing the strength of the La Niña. The MEAN is a 2010-2011 strength La Nina in the latest update (-1.6 to -1.7 mean), with members ranging from -1.2 to -2.6 (this is the biggest outlier, but there are still a few members below -2). Is this overdone? When looking at the other guidance probably, but with the recent cooling of the subsurface combined with not one member of the cfsv2 having a la nina weaker than low end moderate, I do think the potential for a stronger la nina can’t be ruled out just yet. 

Might be overdone.

[CoastalWx]

6 minutes ago, snowman19 said:

It’s central based for sure….however, if Coastalwx is right and this event goes low-end moderate….I would not want to be south of New England this winter

I wasn't forecasting it, but just saying if a low end happened...I wouldn't be shocked that's all.

[40/70 Benchmark]

2 hours ago, snowman19 said:

It’s central based for sure….however, if Coastalwx is right and this event goes low-end moderate….I would not want to be south of New England this winter

Not worried at all.

[ORH_wxman]

2 hours ago, CoastalWx said:

Might be overdone.

Yeah likely. My guess is around the high-end weak to low-end moderate threshold. 

[George001]

2 hours ago, snowman19 said:

It’s central based for sure….however, if Coastalwx is right and this event goes low-end moderate….I would not want to be south of New England this winter

Yeah northern New England should do well, but southern New England and even NYC should be fine even if the Nina somehow got to -3. The Nina is central based now but based on the subsurface the Nina will likely move east and rapidly strengthen. 

[snowman19]

52 minutes ago, 40/70 Benchmark said:

Not worried at all.

I wouldn’t be either if I lived in New England 

[CoastalWx]

27 minutes ago, George001 said:

Yeah northern New England should do well, but southern New England and even NYC should be fine even if the Nina somehow got to -3. The Nina is central based now but based on the subsurface the Nina will likely move east and rapidly strengthen. 

I wouldn't go by what the anomalies are verbatim. There are so many factors outside of whether region 3.4 is -0.7C or - 1.2C. I care more about where the anomalies are, where the forcing is in the tropics, and what if any blocking. The magnitude of anomalies matter to a point, but I think we give those numbers too much weight.  Of course if we are talking something  -0.5C vs -3C that is another story.

[dmillz25]

53 minutes ago, snowman19 said:

I wouldn’t be either if I lived in New England 

A low end moderate niña would still be good for the NYC metro. I would worry further south. Blocking would have something to say as well

[40/70 Benchmark]

Last major primer for outlook.

https://easternmassweather.blogspot.com/2021/09/structural-nuances-in-la-nina.html

[George001]

1 hour ago, CoastalWx said:

I wouldn't go by what the anomalies are verbatim. There are so many factors outside of whether region 3.4 is -0.7C or - 1.2C. I care more about where the anomalies are, where the forcing is in the tropics, and what if any blocking. The magnitude of anomalies matter to a point, but I think we give those numbers too much weight.  Of course if we are talking something  -0.5C vs -3C that is another story.

A coupled -3C super Nina with severe North Atlantic blocking and a cooperative polar vortex would be really good in the Boston area in my opinion. Going by just the Enso states to snowfall correlation we have approximately the same average in a strong La Niña as we do in Enso neutral, yet people start panicking when they see a strong Nina in the forecast. Not just the mid Atlantic people, even posters on this board were saying how horrible the upcoming winter pattern would be due to the stronger La Niña (the Nina didn’t even end up being strong like expected, it peaked at moderate). Last winter wasn’t anything special but it wasn’t a ratter like many expected. I never understood the fear of La Niña here in New England, if anything when we get severe North Atlantic blocking I would rather have a Nina. The models as well as the current ocean temps make me thing this coming winter will have severe North Atlantic blocking for at least 2 months from December to March, especially the 1st half of winter. The blocking will be more extreme than last winter in my opinion, it will rival 2009-2010/2010-2011 levels. With that in mind I fully welcome a La Niña and hope that it is strong enough to counteract the blocking enough that storms don’t miss to the south. 

[40/70 Benchmark]

58 minutes ago, George001 said:

A coupled -3C super Nina with severe North Atlantic blocking and a cooperative polar vortex would be really good in the Boston area in my opinion. Going by just the Enso states to snowfall correlation we have approximately the same average in a strong La Niña as we do in Enso neutral, yet people start panicking when they see a strong Nina in the forecast. Not just the mid Atlantic people, even posters on this board were saying how horrible the upcoming winter pattern would be due to the stronger La Niña (the Nina didn’t even end up being strong like expected, it peaked at moderate). Last winter wasn’t anything special but it wasn’t a ratter like many expected. I never understood the fear of La Niña here in New England, if anything when we get severe North Atlantic blocking I would rather have a Nina. The models as well as the current ocean temps make me thing this coming winter will have severe North Atlantic blocking for at least 2 months from December to March, especially the 1st half of winter. The blocking will be more extreme than last winter in my opinion, it will rival 2009-2010/2010-2011 levels. With that in mind I fully welcome a La Niña and hope that it is strong enough to counteract the blocking enough that storms don’t miss to the south. 

Why must everything be extreme?

[40/70 Benchmark]

2 hours ago, CoastalWx said:

I wouldn't go by what the anomalies are verbatim. There are so many factors outside of whether region 3.4 is -0.7C or - 1.2C. I care more about where the anomalies are, where the forcing is in the tropics, and what if any blocking. The magnitude of anomalies matter to a point, but I think we give those numbers too much weight.  Of course if we are talking something  -0.5C vs -3C that is another story.

Yes times a million. I just did a blog post on this.

[40/70 Benchmark]

5 hours ago, CoastalWx said:

Might be overdone.

Definitely is. No way it gets that strong.

[40/70 Benchmark]

2 hours ago, snowman19 said:

I wouldn’t be either if I lived in New England 

Just bc the northern mid atl may not do as well as NE doesn't mean is a terd for them. 

[40/70 Benchmark]

3 hours ago, George001 said:

Yeah northern New England should do well, but southern New England and even NYC should be fine even if the Nina somehow got to -3. The Nina is central based now but based on the subsurface the Nina will likely move east and rapidly strengthen. 

It's going to drift west and slowly strengthen based on subsurface. 

[CoastalWx]

1 hour ago, 40/70 Benchmark said:

Last major primer for outlook.

https://easternmassweather.blogspot.com/2021/09/structural-nuances-in-la-nina.html

That looks tasty. Right on the gradient at H5. Cold to the north. Ridging into AK...but not a massive -PNA.

[40/70 Benchmark]

2 minutes ago, CoastalWx said:

That looks tasty. Right on the gradient at H5. Cold to the north. Ridging into AK...but not a massive -PNA.

I know...that is the middle ground solution, too...JMA is 95-96, and French is 1999-2000

[40/70 Benchmark]

Euro is most supported by current ENSO configuration and subsurface.

[raindancewx]

14 hours ago, snowman19 said:

Are there any analogs for 2nd year weak La Niña (Modoki), -QBO, rising solar, -PDO? 

From the draft of my winter outlook.

[ORH_wxman]

3 hours ago, CoastalWx said:

That looks tasty. Right on the gradient at H5. Cold to the north. Ridging into AK...but not a massive -PNA.

Yeah that look would be cold here and probably pretty active. Almost looks like a ‘93-94 but shifted a little east with the PV anomaly. 

[40/70 Benchmark]

1 hour ago, raindancewx said:

From the draft of my winter outlook.

This looks more like the modoki composite at H5....we'll see. Gonna need the la nina to shift a lot more west, like the French guidance.

 

 

[40/70 Benchmark]

19 minutes ago, 40/70 Benchmark said:

This looks more like the modoki composite at H5....we'll see. Gonna need the la nina to shift a lot more west, like the French guidance.

 

 

 

[40/70 Benchmark]

Looking at the rest of the data...NCEP looks good. France guidance def, worst....warm and dry. UK is mild, but active...would probably be okay for at least CNE on north. Canadian is meh...bit mild, probably average precip.

Its mostly about where the most negative anomalies end up in la nina, but there are of course others factors at play....especially the weaker la nina is.

[raindancewx]

The current look in the Pacific is something like a basin wide very weak La Nina or cold Neutral. The subsurface readings may already be near their coldest values. A lot of the La Ninas with earlier peaks spend late Fall and Winter with retreating subsurface cold, it becomes more similar, by trend to a strengthening (warming) El Nino subsurface. That's why you can get a relatively cold signal in the Southwest in some of the more special cases. There is less cold at the surface by Peru this year but more is coming, and similar readings to last year in Nino 4 currently. I could see this event being a pretty normal basin-wide look rather than an east-based or Modoki look for winter. I'm not super hung up on it though because I think we'll be returning to Neutral conditions much faster than last year.

Here is what happened after the subsurface trend reversals last year (flip from cold trend to warm trend). Scale on all of these is -7 or colder for deep purple, +7 or colder for deep red, in units of 2 degrees Fahrenheit. 

Opposite flip, from trending warmer from a cold start, to colder from a warm start:

[sebastiaan1973]

A weaker than normal stratosphere at 10 hPa. EC46.q

[40/70 Benchmark]

6 hours ago, raindancewx said:

The current look in the Pacific is something like a basin wide very weak La Nina or cold Neutral. The subsurface readings may already be near their coldest values. A lot of the La Ninas with earlier peaks spend late Fall and Winter with retreating subsurface cold, it becomes more similar, by trend to a strengthening (warming) El Nino subsurface. That's why you can get a relatively cold signal in the Southwest in some of the more special cases. There is less cold at the surface by Peru this year but more is coming, and similar readings to last year in Nino 4 currently. I could see this event being a pretty normal basin-wide look rather than an east-based or Modoki look for winter. I'm not super hung up on it though because I think we'll be returning to Neutral conditions much faster than last year.

Here is what happened after the subsurface trend reversals last year (flip from cold trend to warm trend). Scale on all of these is -7 or colder for deep purple, +7 or colder for deep red, in units of 2 degrees Fahrenheit. 

Opposite flip, from trending warmer from a cold start, to colder from a warm start:

I agree with you on it not being purely modoki or east-based...I have it as mixed type, like last year's event.

[George001]

The CFSv2 has the coldest anomalies in the enso 3.4 and enso 3 regions, with less cold in the enso 4 and 1.2 regions. this is what it has at the peak-

enso 4 mean: -.6
enso 3.4 mean: -1.6

enso 3 mean: -1.6

enso 1.2 mean: -.8 

strength: strong la nina

 

Not really west based like 2016-2017 but not east based like 2017-2018 either, mixed type for sure. The european guidance has a weaker overall La Niña with a mean of -.5 or so. Somewhere in the middle is likely what we end up seeing, with the La Niña moving to the east some but not enough to be truly east based, and being low end moderate strength (around -1.2 or so) The Nina has been doing a good job at helping cool off the Pacific Ocean, which should help prevent the pacific jet from going crazy. That should prevent a trough from developing in the west.

[40/70 Benchmark]

28 minutes ago, George001 said:

The CFSv2 has the coldest anomalies in the enso 3.4 and enso 3 regions, with less cold in the enso 4 and 1.2 regions. this is what it has at the peak-

enso 4 mean: -.6
enso 3.4 mean: -1.6

enso 3 mean: -1.6

enso 1.2 mean: -.8 

strength: strong la nina

 

Not really west based like 2016-2017 but not east based like 2017-2018 either, mixed type for sure. The european guidance has a weaker overall La Niña with a mean of -.5 or so. Somewhere in the middle is likely what we end up seeing, with the La Niña moving to the east some but not enough to be truly east based, and being low end moderate strength (around -1.2 or so) The Nina has been doing a good job at helping cool off the Pacific Ocean, which should help prevent the pacific jet from going crazy. That should prevent a trough from developing in the west.

The PAC jet is all about what happens near AK...you want higher heights around AK, like NCEP, EURO and JMA have. The French and to a lesser extent, the UK guidance are more hostile there. The westerly modoki la nina is more likely to have issues with the pac jet bc the Aleutian ridge is more suppressed and does not extend north into AK. The la nina events with colder anomalies further east tend to pop a ridge further north that extends into AK.

You are going to have a ridge near the Aleutians in a la nina due to the Hadley Cell configuration, just as you will a trough in an el nino...its all about placement of anomalies that determines the precise location/configuration, as Scott said.

[George001]

This is very interesting, the polar vortex is forecasted to be the weakest we have seen in years. Last year, we had a severe polar vortex event in late dec, and severe North Atlantic blocking developed and stayed in place from early Jan to mid Feb, then the pattern broke down and we had a milder regime from then until early- mid April, too late for a return to winter (we had nice storm where I forecasted a massive blizzard for all of eastern mass in mid April, but the temps were just too warm and the snow did not accumulate. I forecasted 2 feet for my area, got a dusting).
 

This year it looks like we could see a polar vortex event as early as mid-late November if the models are correct, which makes me think we could have our first window of North Atlantic blocking from early December to mid Jan. The pattern then probably starts to break down leading to less North Atlantic blocking from late Jan to early March. It is very possible we see a thaw during that timeframe if the polar vortex does not cooperate. After the North Atlantic blocking regime breaks down, it will have done its job enough to force the polar vortex south, leading to a polar vortex intrusion during the second half of the first blocking regime to a couple weeks after. That probably sets in from late Dec to early Feb. If this window is accurate, the second half of Feb is probably going to suck (similar to 2017-2018). March is where things get really interesting, due to the timing of our polar vortex event, like 2018 while we are in a sucky late Feb pattern there will probably be enough time for another polar vortex event to occur, leading to the development of North Atlantic blocking throughout the entire month of March and into mid April. This is not a guarantee, but due to our winter thaw being from mid Jan-late Feb instead of mid Feb-mid March, that opens up a second window in March (like 2018) rather than last winter. That is the biggest difference between the 2017-2018 winter and last year, what happened in March.

what I am thinking we could see right now:

biggest windows (2010-2011 type potential due to blocking and a polar vortex intrusion at the same time) :  late Dec-mid Jan, early March- late March

other windows (high variance, could be epic could suck, really I have no idea yet. What I will try to figure out before my winter forecast in November): early Dec-late Dec, mid Jan-early Feb

Will likely suck: mid-late Feb

The biggest question for me looking at the models is will the polar vortex cooperate, or will it displace too far west? If it displaces too far west, the mid Jan- early feb window will probably suck due to lack of blocking and a trough in the west. If everything comes together, there is a real chance that we only have a hostile pattern for 2 weeks throughout the entire winter. If nothing breaks our way with the polar vortex, we still have early Dec-mid Jan and then another shot in March, with a 1 month period of suck from late Jan-late Feb.
That is our floor in my opinion, and that can still be a damn good winter. The 2017-2018 winter we had a month of suck in Feb. The 2012-2013 winter we had a month of suck in Jan, and the 2014-2015 and 2010-2011 winters we had at least a month of suck (2014-2015 was a month and a half of suck Dec to mid Jan, and 2010-2011 was 2 months of suck Feb-Mar). 2010-2011 in particular we wasted half the damn winter and still got 80 inches of snow in Boston. 2014-2015 we wasted the first half of winter and got hammered the second half. I see 2 good windows at least, which is not something that could be said about 2019-2020 or 2011-2012.