2025-2026 ENSO

[snowman19]

17 hours ago, so_whats_happening said:

Remarkably similar 2 month period with some probably pretty important differences.

One important difference is the AAM. Last year at this time it was in full on El Nino (positive). This year, it is and has been very strongly negative 

[40/70 Benchmark]

1 hour ago, snowman19 said:

One important difference is the AAM. Last year at this time it was in full on El Nino (positive). This year, it is and has been very strongly negative 

Another important difference is the character of La Nina....hard pressed to find many weak/east based Nina events that occured during -QBO that didn't feature some blocking. Although 2005-2006 was pretty mild mid season, it was wintry in December and featured big blocking in March.

[chris21]

1 hour ago, snowman19 said:

One important difference is the AAM. Last year at this time it was in full on El Nino (positive). This year, it is and has been very strongly negative 

Could lead to more blocking.

[snowman19]

Another important difference is the character of La Nina....hard pressed to find many weak/east based Nina events that occured during -QBO that didn't feature some blocking. Although 2005-2006 was pretty mild mid season, it was wintry in December and featured big blocking in March.

It would not call this a pure east-based La Niña. Not CP/Modoki, but this does not look like a 2017 evolution, which was a true east-based event

[40/70 Benchmark]

26 minutes ago, snowman19 said:

It would not call this a pure east-based La Niña. Not CP/Modoki, but this does not look like a 2017 evolution, which was a true east-based event

The forecast winter EMI from JAMSTEC is very 2018 like...along with 1995 and 2021.

The newest El Niño Modoki Index (EMI) guidance from JAMSTEC has also remained fairly consisted in it's depiction of an EMI value of around -.20 to -.30 during the boreal winter season.

 

 

This range is similar to the EMI analogs of 1995-1996, 2017-2018 and 2021-2022, which is supported by the similarity in both the placement (near 140 longitude) and the intensity of the respective subsurface cold pool analogs relative to 2025.

 

[40/70 Benchmark]

I'm in no way implying a 1995 repeat...I understand how different the western PAC is and how much we have warmed...I get it. Just saying ENSO in a vacuum is a decent match.

[mitchnick]

BAM wx video regarding winter worth a listen imho.

 

[anthonymm]

8 hours ago, 40/70 Benchmark said:

100%.

This is why I am so confident that my area will see more snowfall, even if it's a bit warmer. I do not feel warmth will be prohibitive for the vast majority of the season...at least not at this latiitude.

So to be clear, last year was too suppressed for nyc, but next will be too much se ridging for us. Cool, cool we always lose. 

[Stormchaserchuck1]

On 10/9/2025 at 5:25 PM, so_whats_happening said:

Remarkably similar 2 month period with some probably pretty important differences.

That's really about as close of a match as you ever are going to get, the only place in the world that was really different was south of South America.. I think after the Solar Flares in May 2024, the Earth went into a pattern. A lot of this is described as +AO, but that pattern continues now going into the cold season I think.  The 4-corners High pressure wasn't as strong this Summer as last, and that did show tendency to become +PNA last Winter, so maybe not so much +PNA this Winter, but 24-25 is a good analog going forward. 

[snowman19]

[bluewave]

New JMA has Greenland to Eastern Canada blocking linking up with Southeast ridge in the means. Variable PNA with a ridge off the California Coast and an Aleutian ridge. Active storm track through the Great Lakes and a quiet Southern stream. Several elements related to the dominant pattern in recent years.

https://ds.data.jma.go.jp/wmc/products/model/map/7mE/map1/zpcmap.php

 

 

 

[snowman19]

@Bluewave This may end up being the strongest storm/low in history for the Bering Sea….almost 950mb

[qg_omega]

5 hours ago, bluewave said:

New JMA has Greenland to Eastern Canada blocking linking up with Southeast ridge in the means. Variable PNA with a ridge off the California Coast and an Aleutian ridge. Active storm track through the Great Lakes and a quiet Southern stream. Several elements related to the dominant pattern in recent years.

https://ds.data.jma.go.jp/wmc/products/model/map/7mE/map1/zpcmap.php

 

 

 

more blocking too far south linking up with the SE ridge, rinse and repeat 

[GaWx]

 Some of what I’ve learned about IOD index history:

- Tends to be strongest + during strong El Niño with peak a little earlier

- Vast majority of months -IOD 1870-1960 with gradual decrease of -IOD domination since then, especially last 20 years

- 1870-1913: 3 of the only 4 years with consecutive +IOD months were during strong El Niños of 1877, 1896, and 1902. The other (1884) was when it was borderline warm neutral/wk Nino preceding wk Nino.

- Highest IOD month 1870-1960 was only +0.558 (1877)!

- But since 1960, there have been ~34 months >+0.558!

- Longest +IOD string of months 1870-1960 was only 5 months (Nino years 1877 and 1920)

- 1961-present there were ~21 of the 5+ month +IOD streaks

- 1961-2022: longest +IOD streak 23 mos 2018-20 followed by 21 mos 2023-4!

- Record high IOD: +1.279 (Nov of 1997)

- Thus for whatever reason, the IOD has been rising over the last 100+ years and especially the last 20 years. Is GW leading the W Indian Ocean to warm more quickly than the E Indian Ocean? If so, why?

 I’m using the table at the link below for IOD back to 1870:

https://psl.noaa.gov/gcos_wgsp/Timeseries/Data/dmi.had.long.data

@snowman19

[snowman19]

 Some of what I’ve learned about IOD index history:
- Tends to be strongest + during strong El Niño with peak a little earlier
- Vast majority of months -IOD 1870-1960 with gradual decrease of -IOD domination since then, especially last 20 years
- 1870-1913: 3 of the only 4 years with consecutive +IOD months were during strong El Niños of 1877, 1896, and 1902. The other (1884) was when it was borderline warm neutral/wk Nino preceding wk Nino.
- Highest IOD month 1870-1960 was only +0.558 (1877)!
- But since 1960, there have been ~34 months >+0.558!
- Longest +IOD string of months 1870-1960 was only 5 months (Nino years 1877 and 1920)
- 1961-present there were ~21 of the 5+ month +IOD streaks
- 1961-2022: longest +IOD streak 23 mos 2018-20 followed by 21 mos 2023-4!
- Record high IOD: +1.279 (Nov of 1997)
- Thus for whatever reason, the IOD has been rising over the last 100+ years and especially the last 20 years. Is GW leading the W Indian Ocean to warm more quickly than the E Indian Ocean? If so, why?
 I’m using the table at the link below for IOD back to 1870:
https://psl.noaa.gov/gcos_wgsp/Timeseries/Data/dmi.had.long.data
[mention=13098]snowman19[/mention]

This current -IOD is the strongest in 17+ years

[GaWx]

1 hour ago, snowman19 said:

This current -IOD is the strongest in 17+ years

 

 

 

 

Per the monthlies, the lowest since 2008 was July 2016 followed by Oct 2022. Before that comparable lows were in Oct-Nov 1998 and then in Jul-Nov 1996 with Oct 1996 the lowest 1959-present. The lowest on record back to 1870 is Sept of 1906 followed by Sept of 1933.

 For whatever reason, both bottoms and tops tend to occur during Sept-Nov. (~2 months before ENSO bottom/top) more than other times. So, I expect this to bottom by Nov. Colder El Niños have tended somewhat to have less + or even -IOD in fall.

[raindancewx]

Cold patch this month in the West should expand. Not really that similar to last October when the West was blazing.

 

The cold season still looks much better than last year to me too. You could already see what we were heading into by the end of October last year -

Lot of drought nuking rain coming the next five days. That near record setting storm in the North Pacific is a feature of the winter by the way, not a bug. You will have very powerful storms in the winter.

[raindancewx]

Relatively canonical +WPO look for temps in Oct so far - if displaced slightly.

November is very different though if it holds.

[raindancewx]

By the way, I settled on this for analogs for temperatures for the cold season:

Oct, Nov, Dec, Jan, Feb: 2013-14 (x4), 2024-25 (x4), 2018-19, 2022-23

Mar, Apr: 2019 (x4), 2023 (x4), 2014, 2025

Couple pretty cold months in there, but its not really long-lasting or consistent where it shows. Snow anomaly looks like a smiley face, going from Montana-Idaho border to NM-CO border in the West, Ozarks shooting NE to interior New England/Maine for heavy snow. In between (OK/NE New Mexico, North TX, etc) will have some nasty ice storms.  I went below average for snow northern plains. I expect very little snow here for most of the actual winter, but there are windows in November, late Feb-late Apr that should be productive.

For winter precipitation I used the Mar/Apr weighting for wetness/dryness.

Jan-Mar has retrograding cold shots as the La Nina rapidly collapses while cold air is still around. So by March its Plains/West, but for January Plains/East.