2025-2026 ENSO

[bluewave]

4 hours ago, jm1220 said:

Yep, I don’t expect any real change to our lousy winters here until the W PAC meaningfully changes-cools down. It’s clear it keeps fueling these ridiculous Pacific Jet patterns that ruin any snow setup we have one way or another. It’s really something how no matter what the setup is, there’s some turd in the punchbowl that ruins it. It originates from too much chaos and progressiveness in the pattern-too many S/Ws so nothing can amplify, or the ridge/trough in the wrong place so we get cutters, or the continent flooded in maritime air. 

Yeah, the record SST warmth to the east of Japan when coupled with the Siberian air masses to the west over Northeast Asia really increase the gradient and Jet Stream across the Pacific. This leads to storm tracks cutting through the Great Lakes, hugging the I-78 to I-84 corridor, or getting suppressed to our south.This is why Philly to Boston experienced the lowest 7 year snowfall totals since 18-19 since the BM tracks have been missing. 

In the much warmer climate since the 1990s, we haven’t had an average to above an average snowfall season without an active 40/70 BM storm track. Prior to the 1990s we could get to closer to average snowfall without the BM tracks since the air masses were cold enough for more significant front end snows with the hugger tracks before the changeover occurred. We also used to get more snowy clippers in those days dropping to our south. But this storm track has shifted closer to the Great Lakes.

Perhaps in the coming years we can find a way to shift the warm pool east of Japan a bit and allow that Jet to back off a bit. But it’s really a big unknown with the way the subtropical oceans have seen record warming in recent years.

There was a record BM storm track from 09-10 to 17-18. This shifted to the opposite extreme since 18-19. We are reminded what happened with the storm track shift west of the APPS for State College. They had a record snowfall regime from the 60s to 90s with many historic inside runners just east of the APPS. That track had pretty much become dormant since 03-04. So there snowfall has been in steep decline since then as more storms are cutting west of the mountains now.

We just don’t know enough about forecasting very long range storm track patterns to determine if the BM storm track goes the way of the inside runner east of the APPS or we can see at least some intermittent BM tracks in the coming years.

[Stormchaserchuck1]

You aren't going to see benchmark storm tracks with the NAO so positive in the Wintertime.. It's been positive 14 Winter's in a row (and negative in other seasons). It's no mystery. This is actually a really high correlation. 

[LibertyBell]

1 hour ago, michsnowfreak said:

Interesting. I feel that DTW is a good centralized spot for southeast Michigan (and not because I live close lol). The far northern suburbs with their slight tick in elevation are snowier and year-round colder than the rest of the region, and downtown Detroit and especially east of their is too marine influenced. But DTW is a perfect spot, and I feel that is what most NWS offices should do, pick the most "centralized" spot.

I always assumed that was central park, but if its LGA it should be LGA. Any mets from NYC post here? Why dont they question central parks measurements when they seem low? NWS has every right to do that (same as if it was too high).

Not only do the on air TV Mets question Central Park snowfall totals they also question their temperatures (in the summer they are too low) and their wind speeds (also too low).  That ASOS there has a major siting issue. And yet they still use it lol.

 

[LibertyBell]

59 minutes ago, Stormchaserchuck1 said:

You aren't going to see benchmark storm tracks with the NAO so positive in the Wintertime.. It's been positive 14 Winter's in a row (and negative in other seasons). It's no mystery. This is actually a really high correlation. 

It's been theorized that because of CC we will see many more +NAO in the winter and many more -NAO in the spring.

[Stormchaserchuck1]

9 minutes ago, LibertyBell said:

It's been theorized that because of CC we will see many more +NAO in the winter and many more -NAO in the spring.

Everyone fits everything that's happening with everything that's happening. 

I don't see the correlation between CC and +NAO, because the NAO is sea-level pressure difference between two areas. One negative, one positive. 50/50. It's not an index that is always measuring warming vs cooling.  The problem is that the south part of the NAO has run warm over the last 14 Winter's. I think it's been split 50% negative and 50% positive events in the Summer during that time. 

[bluewave]

1 hour ago, Stormchaserchuck1 said:

You aren't going to see benchmark storm tracks with the NAO so positive in the Wintertime.. It's been positive 14 Winter's in a row (and negative in other seasons). It's no mystery. This is actually a really high correlation. 

We had great snows during the +NAO winters in 04-05, 13-14, 14-15, 15-16, 16-17 and 17-18. So the Pacific Jet has had more influence than the teleconnections in determining the BM storm tracks and snowfall in this area. The -NAO only helps snowfall when the Pacific Jet relaxes and the -NAO doesn’t link up with the Southeast Ridge. 

[Stormchaserchuck1]

8 minutes ago, bluewave said:

We had great snows during the +NAO winters in 04-05, 13-14, 14-15, 15-16, 16-17 and 17-18. So the Pacific Jet has had more influence than the teleconnections in determining the BM storm tracks and snowfall in this area. The +NAO only helps snowfall when the Pacific Jet relaxes and the NAO doesn’t link up with the Southeast Ridge.

The correlation composite takes into account over 1,000 data points. A 0.6 correlation on SLP on the benchmark means it happens 2/10 times, x100. You can get good snows in +NAO Winter's, especially because -NAO's tend to be dry.. so +nao when phased with a good Pacific can give you more moisture during a colder pattern.  But I think if we had -NAO this Winter, there would have been benchmark storms.   Something to look for going forward.. it's also an index so can be traced to certain climate phenomena, so not really all that connected to climate change. 

+PNA also has a huge correlation with benchmark low pressure, and -PNA not.. as you are pointing out. 

+NAO/-PNA isn't necessarily climate change. 

[Stormchaserchuck1]

Final NAO this Winter was +0.65/month.. 3/4 months positive, and the lowest being January -0.52. 

@40/70 Benchmark My Atlantic SST method hit within the estimated 0.54 standard deviation this Winter.  (+0.52 forecast vs +0.65 final)

https://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/norm.nao.monthly.b5001.current.ascii.table

[LibertyBell]

12 minutes ago, bluewave said:

We had great snows during the +NAO winters in 04-05, 13-14, 14-15, 15-16, 16-17 and 17-18. So the Pacific Jet has had more influence than the teleconnections in determining the BM storm tracks and snowfall in this area. The -NAO only helps snowfall when the Pacific Jet relaxes and the -NAO doesn’t link up with the Southeast Ridge. 

1993-94 is another example of this

[bluewave]

1 minute ago, Stormchaserchuck1 said:

The correlation composite takes into account over 1,000 data points. A 0.6 correlation on SLP on the benchmark means it happens 2/10 times, x100. You can get good snows in +NAO Winter's, especially because -NAO's tend to be dry.. so +nao when phased with a good Pacific can give you more moisture during a colder pattern.  But I think if we had -NAO this Winter, there would have been benchmark storms. 

Those correlation composites are outdated since they were before we began to see the climate shifts in recent years. So newly emergent patterns will always have smaller sample sizes to draw from than from a colder stable era over decades and decades. January 2025 was one of the strongest -NAO winter months of the 2020s with very little snow to show for it. Same went for March 2023 with a strong -NAO. 

 

[Stormchaserchuck1]

1 minute ago, bluewave said:

Those correlation composites are outdated since they were before we began to see the climate shifts in recent years. So newly emergent patterns will always have smaller sample sizes to draw from than from a colder stable era over decades and decades. January 2025 was one of the strongest -NAO winter months of the 2020s with very little snow to show for it. Same went for March 2023 with a strong -NAO. 

 

They aren't outdated, the same things are carrying. It's 65 years of data to 2012, but since 2012 we have had +NAO every Winter, and the correlation of benchmark SLP is still +0.6. +0.6=+0.6. The same thing has happened as the historical data.  It ends at 2012, then you are saying it's a mystery why there are no benchmark storms post-2018 and I'm pointing out that the NAO has been very positive in that time. 

1 or 2 or 3 examples isn't going to change anything. I had my best Winter month in January this year since 2016, but yeah it was a little dry.  -NAO has also started going colder the last 2 Winter's. The data's too overwhelming to dismiss it.

[PhiEaglesfan712]

4 hours ago, bluewave said:

We had great snows during the +NAO winters in 04-05, 13-14, 14-15, 15-16, 16-17 and 17-18. So the Pacific Jet has had more influence than the teleconnections in determining the BM storm tracks and snowfall in this area. The -NAO only helps snowfall when the Pacific Jet relaxes and the -NAO doesn’t link up with the Southeast Ridge. 

16-17 wasn't a great snow winter, especially south of Philly. It even ranks among the Top 10 least snowy winters in Baltimore (3 inches) and Washington DC (3.4 inches).

[40/70 Benchmark]

4 hours ago, Stormchaserchuck1 said:

Final NAO this Winter was +0.65/month.. 3/4 months positive, and the lowest being January -0.52. 

@40/70 Benchmark My Atlantic SST method hit within the estimated 0.54 standard deviation this Winter.  (+0.52 forecast vs +0.65 final)

https://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/norm.nao.monthly.b5001.current.ascii.table

Awesome...also means may NAO forecast was good because we were in lock-step on that this year.

[40/70 Benchmark]

On 11/15/2024 at 11:22 AM, 40/70 Benchmark said:

Just realized I never threaded this in the NE subforum, which I usually do....I prefer to update in here, rather than the main forum.

 

https://easternmassweather.blogspot.com/2024/11/using-past-forecasting-difficulty-to.html

 

 

 

 

 

 

Yea, looks like I had +.38 to +.68 for DM mean NAO.

[40/70 Benchmark]

5 hours ago, Stormchaserchuck1 said:

The correlation composite takes into account over 1,000 data points. A 0.6 correlation on SLP on the benchmark means it happens 2/10 times, x100. You can get good snows in +NAO Winter's, especially because -NAO's tend to be dry.. so +nao when phased with a good Pacific can give you more moisture during a colder pattern.  But I think if we had -NAO this Winter, there would have been benchmark storms.   Something to look for going forward.. it's also an index so can be traced to certain climate phenomena, so not really all that connected to climate change. 

+PNA also has a huge correlation with benchmark low pressure, and -PNA not.. as you are pointing out. 

+NAO/-PNA isn't necessarily climate change. 

That is the sweet spot for this area IMO.

[PhiEaglesfan712]

Perhaps the most amazing thing about the record amount of snow storm tracks from about 3/1/2009 to 1/23/2016 is that we had a 2-winter record low snow stretch (2011-12 and 2012-13) right in the middle of it!

 

[bluewave]

10 hours ago, PhiEaglesfan712 said:

Perhaps the most amazing thing about the record amount of snow storm tracks from about 3/1/2009 to 1/23/2016 is that we had a 2-winter record low snow stretch (2011-12 and 2012-13) right in the middle of it!

 

That’s a function of the all or nothing snowfall regime which began in the 1990s as the winters have warmed. To reach normal to above normal snowfall has fallen squarely on the shoulders of BM storm tracks which most times were NESIS ranked KU events.

The years without BM tracks and KU events were duds since the 1990s and the years with BM tracks were great. Since we lost the BM storm track in 18-19, nearly all the seasons with the exception of 20-21 around NYC were well below average. This is the risk of relying exclusively on one type of storm track to reach normal seasonal snowfall.

When it was much colder from the 1960s to early 1990s we had a wider variety of storm tracks to reach average. So plenty of very cold winters without benchmark KU events broke even. These were the moderate storms with took BM tracks but didn’t rank on the KU scale.

 So in a colder climate we were able to nickel and dime our way to close to normal. These days nickel and dime events which were frequent this past winter just couldn’t get the job done since the storm tracks were so warm on the days with precipitation over .25 around NYC.

[Stormchaserchuck1]

Historic snowfall only happened a short time ago.  I remember in the early 2000s, when every low would hug the coast, that it must be a gravity of -NAO. 

What we are in is definitely a "pattern". SE ridge amplified from +NAO/-PNA. The NAO decadal is about as positive as it will ever be, although we once in a while get Greenland blocks (more -AO). It's the mid-latitudes where the Hadley Cell and Mid Latitude Cell in the Atlantic interact that is our problem.. there is always High pressure there in recent Winters. That area usually extends to the east coast. 

Combined, -NAO and +PNA have benchmark SLP correlation at -0.85! That is 9/10 vs average. I think we've had that combo 3 Winter months since 2016 (when the normal frequency should be 1/4). 

[FPizz]

21 hours ago, michsnowfreak said:

Interesting. I feel that DTW is a good centralized spot for southeast Michigan (and not because I live close lol). The far northern suburbs with their slight tick in elevation are snowier and year-round colder than the rest of the region, and downtown Detroit and especially east of their is too marine influenced. But DTW is a perfect spot, and I feel that is what most NWS offices should do, pick the most "centralized" spot.

I always assumed that was central park, but if its LGA it should be LGA. Any mets from NYC post here? Why dont they question central parks measurements when they seem low? NWS has every right to do that (same as if it was too high).

There are ex-Mt. Holly Mets on a Philly board that laugh at the Philly temps and acknowledge they are off, but things rarely get fixed it seems.  It took me years of complaining to get New Brunswick NJ temps fixed as it turns out their sensor needed recalibration.   Do you think they ever go back and adjust the years of wrong data, doubt it.  

[Stormchaserchuck1]

Cold water in the subsurface is trying to get squeezed out.. but this negative pool in the central-subsurface should at the very least keep us away from El Nino in the next few months. 

[PhiEaglesfan712]

On 4/11/2025 at 10:59 AM, LibertyBell said:

Even the colder winter worked out which was similar to 2008-09.  We also had the dry January with small snowfalls but long duration snowcover.  Too bad we didn't get the March 2009 analog, Ray!

That March 2009 snowstorm was definitely a turning point. The first part of that season (October 2008-January 2009) had a lot of cold, but not the snow. In fact, there was no real snow event, except for the early February one that got a fluky 8+ inches at PHL. That was more of an isolated storm. The March 2009 one was a Nor-easter and more widespread (it would be the first of many such events in the next 7 years).

[Stormchaserchuck1]

The 90-day SOI is now about as high as it ever got during the La Nina last year

12 Apr 2025	1013.34	1008.55	17.30	10.65	8.13
11 Apr 2025	1013.52	1007.55	25.81	10.49	7.70

It led the lack of strong Nina last year.. while the subsurface and surface were showing signs of a jump negative, the SOI never budged and the event ended up being barely greater than Neutral. Also, since 2020, we've had 82% of the months with +SOI over the 5-year period.. Nina long term state is being somewhat reflected in the SOI

It's been positive the last 48/50 days.. 

 

[bluewave]

21 hours ago, Stormchaserchuck1 said:

They aren't outdated, the same things are carrying. It's 65 years of data to 2012, but since 2012 we have had +NAO every Winter, and the correlation of benchmark SLP is still +0.6. +0.6=+0.6. The same thing has happened as the historical data.  It ends at 2012, then you are saying it's a mystery why there are no benchmark storms post-2018 and I'm pointing out that the NAO has been very positive in that time. 

1 or 2 or 3 examples isn't going to change anything. I had my best Winter month in January this year since 2016, but yeah it was a little dry.  -NAO has also started going colder the last 2 Winter's. The data's too overwhelming to dismiss it.

The NAO was much more positive from 11-12 to 17-18 than it has been from 18-19 to 24-25. Yet there was a record number of BM tracks from 11-12 to 17-18 with the strong +NAO over those winters. But very few BM tracks in the last 7 seasons vs the previous 7 seasons. Which has been reflected in the steep snowfall decrease in places like NYC Metro region. So as I have said, it’s the Pacific Jet driving the decline in BM tracks and snowfall much more than the Atlantic side and teleconnections like the NAO. Trying to use correlations from a different climate era isn’t going to work out. 

 

 

 

 

[Stormchaserchuck1]

It's not about using climate indices from another climate era. That's a wrong/bad point. They are calculated by specific methods, and that methodology is not different in a cooler or warmer planet. It's actually a very strong correlation, benchmark low pressures and the state of the NAO and PNA. I will argue this one. Here's the PNA:

The PNA is very negative in the 2018-2025 example you posted. Such an extreme state really tightens up on these correlation numbers. (The map above is default positive, but includes both states of the index). 

The NAO is not a Greenland High pressure.. Greenland isn't part of the Atlantic Ocean. It's a calculated sea level pressure between ~The Azores, and ~Iceland. That's a SLP anomaly. One region has positive readings vs the 2nd region negative readings and visa-versa. It's not a function of climate change, because that's 50/50. The lower part (~Azores) is where the mid-latitude and Hadley Cells meet, and more often than not extends west to have similar conditions as the east coast, US. 

The example I'm posted represent a total of 784 months. So +NAO has benchmark tracks 200/784, and -NAO has benchmark tracks 584/784. Then the PNA is also correlated (not related to the 1st set of numbers). The correlations of these Pacific and Atlantic representative indices are actually really high for something so specific as as coastal pressure systems. It's large scale phenomena that has not been favorable lately. The -NAO was more favorable for benchmark tracks in the early 2000s. 

-PNA and +NAO together have benchmark tracks something like 35/384. +PNA and -NAO together has benchmark tracks 349/384.  There is nothing post-2012 that has happened differently from the 1949-2012 period. It's calculated the same, and is having the same effects. The PNA has been negative, and the NAO has been positive. A small time period (with somewhat +pna conditions your map shows) does not negate the total dataset. 

Remember too the correlation composites include both sides of the index, so +NAO and -NAO are included in the same correlation map. Over the last 10 Winters or whatever, the +NAO correlation with lack of benchmark low pressure has been really strong. This matches the historical data. 

[Stormchaserchuck1]

Your issue is with the CPC and how they measure the NAO. I've been impressed though over the last few Winters - their methodology has correlated with X conditions over the east coast more than what happens over Greenland and the Davis Strait. Many times in the last few years we had a SE ridge with Greenland block, but their index says it's positive during that time. You might say there is something wrong with that, but the methodology has nothing to do with the east coast. In other words, Greenland block is correlating -0.4, but their methodology has been at -0.6 to -0.7, for something independent. Like I said, it's a specific measure of sea-level pressure over the North Atlantic ocean, which is not always completely connected to Polar blocking.  

[bluewave]

18 hours ago, Stormchaserchuck1 said:

It's not about using climate indices from another climate era. That's a wrong/bad point

Correlations or associations shift over time with the climate. From the 1950s to early 1970s -PNA -NAO -AO was associated with a trough in the East. But in recent times this has featured a strong Southeast Ridge. Even the -NAOs and -AOs  have been occurring with a strong Southeast Ridge. My guess as to why this has been the case is due to the rapid warming of the Atlantic Ocean leading to a stronger subtropical ridge. So when we used to get more of a trough in the East the tendency has become more of a Southeast Ridge. This is the weakness's of just relying on the older teleconnections like NAO, AO, PNA, and EPO and not recognizing changes in the ridge structures and orientations further south. Plus the much stronger Pacific Jet is playing a role in the ridge strength also. 

[Stormchaserchuck1]

I guess you have it stuck in your head, the 12/20 times it didn't happen vs the 500/784 that I'm pointing out it did. 

My point is that the NAO is strongly correlated with benchmark low pressure systems. And that we've had 14 straight +NAO Winters in a row. That's all. 

[Stormchaserchuck1]

Another really high correlation is state of the AO and benchmark storms. I will give this one to bluewave.. that lately this one has not been hitting, although you can see it's kind of mutable, where NAO is right on the coast. 

[bluewave]

2 hours ago, Stormchaserchuck1 said:

I guess you have it stuck in your head, the 12/20 times it didn't happen vs the 500/784 that I'm pointing out it did. 

My point is that the NAO is strongly correlated with benchmark low pressure systems. And that we've had 14 straight +NAO Winters in a row. That's all. 

The main correlation with storm tracks since 18-19 has been the Pacific Jet. We got a relaxation during 20-21 which allowed the  -NAO -AO to produce a KU BM track on 2-1-21 and another smaller BM event about a week later. Also a brief window in January 22 with the MJO 8 +PNA which favored areas from ACY to ISP to BOS. Just a little wide of the BM for areas a little further west to cash in.

But most other times the Pacific Jet has had an overpowering influence leading to cutters, huggers, and suppressed Southern Stream storm tracks. Plus the stronger Southeast Ridge influence even at times of strong -NAO and -AO intervals which was absent before this decade at times of such strong blocking. So this adds a new conditionality to those older correlations. 

So you need to take more of bigger picture view rather than just looking at the NAO in isolation. If you noticed we finally got something close to a BM track the last few days. The reason the lagged -NAO correlation finally worked now and not over the winter was due to the Pacific Jet backing off a bit from recent months. My guess is that the record warmth in Siberia weakened the gradient between the record SST warmth east of Japan allowing the jet to back off.

 

[Stormchaserchuck1]

I don't disagree that that SE ridge has been stronger than usual.. it was really bad 3 Winter's ago, but the last 2 years when Greenland blocking happened, it has actually happened with a cooler pattern. The one big anomaly being this February, but there was a really strong low pressure in the Atlantic at 50N (the -AO was too far north, over the North Pole). 

However, I do think if the CPC NAO goes the direction it has in the Spring/Summer/Fall in the coming Winter's than we will see more benchmark storms and snow. A general warming is definitely occurring, but I'm not ready to connect it to SE ridge, since SE ridge is in play with a number of factors, where something like a Southwest, US High pressure is more independent.. I think a globe warming should be warming the west coast the most.