2025-2026 ENSO

[40/70 Benchmark]

@bluewaveI'm not sure it's entirely fair to use data back to 1895 when determining what constitutes cold in our contemporary climate.....clearly all that was implied was that last year was "colder" relative to the current climo base. No one argued it would have been cold using older climo. The point is it took more than merely a "mismatch month" to be even near normal using the 1991-2020 climo base. Citing how it ranked in history to data back to the 1800s seems like a deflection to me.

No one is arguing against GW....the argument is that last season was colder than expected relative to modern standards, which ironically enough, tacitly acknowledges climate change. I feel like it will be helpful for you to simply lay out specific seasonal temp ranges for winter per 1991-2020 climo  during the fall if you want to remove any ambiguity like this after the fact. Pointing out how the season ranked back to 1895 to defend your nebulous forecast seems less than ideal and only likely to further obfuscate.

[PhiEaglesfan712]

I'm always surprised by the fact that the winter of 2010-11 didn't end up colder than the winter of 2009-10, especially considering that 10-11 was a strong la nina and 09-10 was a strong el nino.

[GaWx]

29 minutes ago, PhiEaglesfan712 said:

I'm always surprised by the fact that the winter of 2010-11 didn't end up colder than the winter of 2009-10, especially considering that 10-11 was a strong la nina and 09-10 was a strong el nino.

The main diff, especially in the SE US, was that Feb of 2011 had a strongly +AO/NAO. Of DJF, F is often the warmest in La Nina.

Edit: Also, in New England and NYC at least, DJF 2010-1 was actually colder than DJF 2009-10.

[snowman19]

The main diff, especially in the SE US, was that Feb of 2011 had a strongly +AO/NAO. Of DJF, F is often the warmest in La Nina.
Edit: Also, in New England and NYC at least, DJF 2010-1 was actually colder than DJF 2009-10.

The thing I remember most about the 10-11 winter was HM nailing that massive NAO/AO blocking over a month before it even happened. It was right around Halloween and he sounded the alarm that the stratosphere and troposphere were “talking” and major high latitude blocking was coming for December and January. And I know people are going to be shocked at this, but I have to give JB credit for accurately calling the complete breakdown of the blocking in February. Around mid-January he warned that winter was going to come to an abrupt end, over and done in the east in February and the NAO/AO were going to collapse and not come back again. The weenies were furious with him, wanted to rip him apart. He turned out to be right

[Stormchaserchuck1]

30-day SOI is back above +5.  17/20 +SOI days in July so far. 

-3c pocket developing in the ENSO-subsurface

[snowman19]

30-day SOI is back above +5.  17/20 +SOI days in July so far. 

-3c pocket developing in the ENSO-subsurface

La Niña cometh

[michsnowfreak]

4 hours ago, 40/70 Benchmark said:

@bluewaveI'm not sure it's entirely fair to use data back to 1895 when determining what constitutes cold in our contemporary climate.....clearly all that was implied was that last year was "colder" relative to the current climo base. No one argued it would have been cold using older climo. The point is it took more than merely a "mismatch month" to be even near normal using the 1991-2020 climo base. Citing how it ranked in history to data back to the 1800s seems like a deflection to me.

No one is arguing against GW....the argument is that last season was colder than expected relative to modern standards, which ironically enough, tacitly acknowledges climate change. I feel like it will be helpful for you to simply lay out specific seasonal temp ranges for winter per 1991-2020 climo  during the fall if you want to remove any ambiguity like this after the fact. Pointing out how the season ranked back to 1895 to defend your nebulous forecast seems less than ideal and only likely to further obfuscate.

I personally am a fan of using 30 year normals. Its been done that way for over a century, updated every 10 years. Obviously i am a huge fan of old climate data (when they used to write in the books with a pen, complete with a description of the day, that can't be beat). Heck i look at old data more than new data. But i think for normals the 30 year are a good marker. It accounts for recent decadal change of temp, precip, and snow. 

Its always fun to use the period of record too, it shows what longterm things have changed more than others, and certainly you can use moving averages or regression lines to see the ups and downs. Theres always some human error element but threaded records for stations that have moved slightly are still very accurate.

But what i DONT like is starting something at a random picked year. I got so sick of seeing "since 1970" nonsense that I decided, hey I can pick a starting point too, lets go back exactly 100 years. Didn't go over well with a few lol. Bottom line for this area, 1970s-80s were full of abnormally cold winters, just as 1930s-50s were full of abnormally mild ones. Picking a starting point like 1930 or 1970 is going to automatically allow a predictable outcome. Either use POR or current 30 year normals. 

If anything, hating on 30 year normals is doing a disservice to the cc that some are so passionate about. We've seen multiple times when an expected warm period becomes colder than normal and then you get "well if it was the 1800s it wouldn't be colder than normal". OK. Well. I got 37.3" snow in 2022-23 which is below avg. If it was 1960 that was slightly above avg. That's irrelevant.

[Stormchaserchuck1]

34 minutes ago, snowman19 said:

La Niña cometh

ONI may not make the 5-month classification. SSTAs are still pretty warm. What's interesting is the difference between 3-month and 5-month classification in ONI since the CPC changed its guidelines a few years ago. If this year doesn't make 5-consecutive months:

5/32 recent years (since 1994) will have been ENSO Neutral, in 3-month ONI

8/32 recent years (since 1994) will have been ENSO Neutral, in 5-month ONI

RONI/MEI are heading for Weak La Nina I think. MEI may even borderline Moderate Nina in a few monthlies. 

I found that central-ENSO-subsurface has the best classification with North Pacific pressure pattern, so if the subsurface cold water continues to strength, watch out for more -PNA N. Pacific patterns in the coming Fall/Winter. 

Very interesting how the SOI was so neutral at this time last year, and this year it's been positive every month since Oct 2024. SOI is kind of in its own world regarding the evolution of ENSO lately, but I think it's a good indicator. 

[Stormchaserchuck1]

11 hours ago, snowman19 said:

@Stormchaserchuck1 Very interesting post/research on why the subsurface is arguing that this is likely going to be a 2nd year “double dip” La Niña:

This La Nina tendency after Strong El Nino's is very interesting. What is happening 1998-2025 that is making it reverse so hard? I would think it's a matter of not having enough data, as ENSO events should run in a continuum but for the last few decades there have been big fluctuations. This happened in the 1970s and 1980s too. 

[40/70 Benchmark]

1 hour ago, Stormchaserchuck1 said:

30-day SOI is back above +5.  17/20 +SOI days in July so far. 

-3c pocket developing in the ENSO-subsurface

I have a new post discussing all of this shortly....good catch.

[PhiEaglesfan712]

52 minutes ago, Stormchaserchuck1 said:

This La Nina tendency after Strong El Nino's is very interesting. What is happening 1998-2025 that is making it reverse so hard? I would think it's a matter of not having enough data, as ENSO events should run in a continuum but for the last few decades there have been big fluctuations. This happened in the 1970s and 1980s too. 

As they say, the strongest el ninos are followed by a strong la nina. Such transitions happened in 1973, 1988, 1998, and 2010. Even in years when a strong el nino didn't transition into a strong la nina, strong el ninos are almost always followed by a la nina. 2024 is only the 2nd time (dating back to the 1972-73 super el nino event) that a strong el nino didn't immediately transition into a la nina (1992 was the other).

A strong el nino following a strong la nina is pretty much unprecedented. Usually, there is a buffer year in between a strong la nina and a strong el nino (like 1956-57 and 2008-09). The only time an el nino immediately followed a strong la nina year was in 1976 (the year the PDO flipped from - to +).

In short, a la nina event is more likely to run in a continuum (see 2020-23 triple la nina, which peak was almost the same each year). El ninos running in a continuum is very rare (the most recent one was the 1986-88 event).

[Stormchaserchuck1]

^Yeah, it's a pretty big anomaly because Strong La Nina's don't result in following El Nino's. Maybe it has something to do with if the event is West or East-based? 

I think you mean 1982, not 1988? Although the moderate El Nino in 87-88 did transition to a strong La Nina the following year. 82-83 was followed by 2 years of La Nina. I think that last year wasn't La Nina, given that it was Weak Nina by other metrics, and that we are doing it again here in the 2nd year means that the same pattern happened after the 23-24 Strong Nino. 

I do think that over 200-300 years of data the same pattern won't continue. But something is happening over the last 50 years that is making stronger Nino's reverse. 

[40/70 Benchmark]

19 hours ago, raindancewx said:

The mismatch thing is just an excuse to say even though all periods should be warm, some will still be cold because the mechanisms driving the warmth are actually only moderately strong correlation rather than direct cause.

It's a bit like people predicting the stock market who always forecast record highs and growth because you get geometric real returns of 7-8% over long periods, even though some years still finish with negative annual returns.

If it was winter right now, the cold Tropical Atlantic, relatively warm Nino 1.2 v. cool Nino 4 would imply a neutral AMO and a Modoki la Nina with the -PDO. You'd see huge dumps of cold alternating between the Plains and West. The precipitation pattern on the Canadian at the equator in winter looks most similar to MJO five for the winter, with four somewhat close too.

I generally use SST indicators as a guideline for predicting the major indices in winter. You can see huge areas of the Atlantic and Pacific predict WPO behavior in winter in the Summer - and favor the +WPO which also favors Western cold in both Fall (Oct-Nov) and Feb-Apr. WPO also tends to 'bully' the NAO primary phase into place to some extent.

Wonder why the CANSIPS is so cool in the NE with MC forcing...

[40/70 Benchmark]

https://easternmassweather.blogspot.com/2025/07/la-neutral-enso-conditions-will.html

[Stormchaserchuck1]

4 minutes ago, 40/70 Benchmark said:

Wonder why the CANSIPS is so cool in the NE with MC forcing...

This is what the CANSIPS had for July at a 0.0 month lead

[40/70 Benchmark]

34 minutes ago, Stormchaserchuck1 said:

This is what the CANSIPS had for July at a 0.0 month lead

Bleh.....anyway, it did pretty well last season and a lot of other guidance looks similar...with the heat centered over TX next winter.

[Terpeast]

3 minutes ago, 40/70 Benchmark said:

Bleh.....anyway, it did pretty well last season and a lot of other guidance looks similar...witth the heat centered over TX.

What caught my attention more than temps is this. Hard to bet on any major coastals if cansips is onto something like it was last year.

[40/70 Benchmark]

29 minutes ago, Terpeast said:

What caught my attention more than temps is this. Hard to bet on any major coastals if cansips is onto something like it was last year.

I don't expect a great storm track....I just think it will be wetter than last year.

[40/70 Benchmark]

Give me near normal temps and slightly below average precip...odds are high I would have my best season in several years, that's how bad it's been.

[Stormchaserchuck1]

12 minutes ago, 40/70 Benchmark said:

Give me near normal temps and slightly below average precip...odds are high I would have my best season in several years, that's how bad it's been.

I wouldn't discount a normal or slightly above normal snowfall season this year in the mean.. but the odds of a big one, like top 5% are probably much less... 1%

[40/70 Benchmark]

1 minute ago, Stormchaserchuck1 said:

I wouldn't discount a normal or slightly above normal snowfall season this year in the mean.. but the odds of a big one, like top 5% are probably much less... 1%

That is pretty much what I am saying....like a 2016-2017 type of season. I don't see a high ceiling, but I think there is also a higher floor than man recent seasons.

[40/70 Benchmark]

The west will do better...no contest. But just give me something flirting with normal and I'd be estatic. 

[KakashiHatake2000]

https://x.com/labry_de/status/1947079474589413814?
wow it looks like a mothership is taking over connecticut

[michsnowfreak]

2 hours ago, Stormchaserchuck1 said:

I wouldn't discount a normal or slightly above normal snowfall season this year in the mean.. but the odds of a big one, like top 5% are probably much less... 1%

This is one of the biggest differences between the Great Lakes and SNE/east coast. The reliance on a monster storm to make or break the season in terms of percent of average. Due to the more frequent snowfalls but less crippling storms, an entire seasons pattern is the bigger indicator here. Don't get me wrong, a 10"+ storm happens and you can all but lock in an above avg snow season, but you can also have a great season if its active even tho the biggest storm is like 6-8". In a place like NYC a monster storm (2016 for example) can make what wouldve been an otherwise crap season an above normal one with one swing of the bat. 

[Stormchaserchuck1]

You might say that these are not big anomalies, but this is the +AO that just won't go away. So persistent since May! There might really be the chance for some -EPO periods this Winter, as I believe a cold H5 over the Greenland part of the Arctic Circle correlates to -epo/+pna actually in the wintertime.. not sure I would forecast anything other than a negative PNA though with what's going on in the Pacific. 

We saw this same pattern last year until September. 

[dmillz25]

13 hours ago, snowman19 said:

The thing I remember most about the 10-11 winter was HM nailing that massive NAO/AO blocking over a month before it even happened. It was right around Halloween and he sounded the alarm that the stratosphere and troposphere were “talking” and major high latitude blocking was coming for December and January. And I know people are going to be shocked at this, but I have to give JB credit for accurately calling the complete breakdown of the blocking in February. Around mid-January he warned that winter was going to come to an abrupt end, over and done in the east in February and the NAO/AO were going to collapse and not come back again. The weenies were furious with him, wanted to rip him apart. He turned out to be right

Crazy to think that if that blocking stuck around even for another week NYC would have been in reach for the snowiest winter in recorded history. That Chicago blizzard would have probably done it

[snowman19]

Crazy to think that if that blocking stuck around even for another week NYC would have been in reach for the snowiest winter in recorded history. That Chicago blizzard would have probably done it

I have no doubt that if the blocking didn’t break down in February, NYC would have seen more snow that winter than the 95-96 winter and probably by a lot

[snowman19]

IMO we are all lined up to see a well below average Atlantic hurricane season in both named storms and ACE

[snowman19]

This La Nina tendency after Strong El Nino's is very interesting. What is happening 1998-2025 that is making it reverse so hard? I would think it's a matter of not having enough data, as ENSO events should run in a continuum but for the last few decades there have been big fluctuations. This happened in the 1970s and 1980s too. 

Indeed. And I definitely agree with you that there is going to be a real strong tendency for -PNA this winter given the 2nd year -ENSO. Very extensive research supports this

[PhiEaglesfan712]

1 hour ago, snowman19 said:

I have no doubt that if the blocking didn’t break down in February, NYC would have seen more snow that winter than the 95-96 winter and probably by a lot

Yeah, even without the blocking, we still had one final hurrah during the final third of March. 

2011-03-23	40	32	36.0	-8.8	29	0	0.87	T	0
2011-03-24	44	30	37.0	-8.2	28	0	0.09	1.0	1
2011-03-25	42	28	35.0	-10.5	30	0	0.00	0.0	0
2011-03-26	40	26	33.0	-12.9	32	0	0.00	0.0	0
2011-03-27	45	28	36.5	-9.7	28	0	0.00	0.0	0
2011-03-28	45	26	35.5	-11.1	29	0	0.00	0.0	0
2011-03-29	49	31	40.0	-6.9	25	0	0.00	0.0	0
2011-03-30	53	36	44.5	-2.8	20	0	0.01	0.0	0
2011-03-31	43	37	40.0	-7.7	25	0	0.13	T	0

This turned a solid warm first two-thirds of the month into a negative departure.