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. 

 

Edit:

Conceptually, I settled on these blends for a couple reasons - the upper air pattern in July-Sept does look like a simple blend of 2013, 2018, 2022, 2024 globally. SSTs are close too. That's not a bad match for the US in Sept or Oct either. But the straight 2013/2024 dominated blend is much closer for US temps than the equal weight blend. 

In 2024-25, the cold was highly concentrated in January nationally and then to the east in February. My La Nina Atlantic ACE to Albuquerque Nov-Feb cold day count index implied 23 days would be at least 5F below the daily average. We had 24. This year with ACE still only 96, the implication is 31 days at least 5F below the daily average. I still expect the La Nina warm signal to show strongly, but the cold wave signal is pretty strong. I'm expecting either one-two major cold waves or several smaller cold snaps. The lower ACE also implies locally "severely cold days" - 10F or more below daily average - should be around 12, instead of the projected 7 last year (we actually had 8 or 9 I believe).

The precipitation blend is still predominantly dry in the southern US, but much wetter than 2024-25.

Additionally, a lot of the hurricane seasons with near no to no activity in the Gulf end up pretty cold late - 2013-14, 2010-11, 1981-82, 1962-63, 2014-15, 2022-23 - if going into an El Nino or trending warmer in Nino 3.4 y/y. 

[Stormchaserchuck1]

This pattern for the end of October doesn't look bad, with +PNA and west-based -NAO developing. This year has been nothing like 2020-2023 where there was strong -PNA all the time. -PNA periods have been in short periods, and sometimes transition to neutral, or in this case a potential +pna

[Daniel Boone]

3 hours ago, raindancewx said:

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. 

 

Edit:

Conceptually, I settled on these blends for a couple reasons - the upper air pattern in July-Sept does look like a simple blend of 2013, 2018, 2022, 2024 globally. SSTs are close too. That's not a bad match for the US in Sept or Oct either. But the straight 2013/2024 dominated blend is much closer for US temps than the equal weight blend. 

In 2024-25, the cold was highly concentrated in January nationally and then to the east in February. My La Nina Atlantic ACE to Albuquerque Nov-Feb cold day count index implied 23 days would be at least 5F below the daily average. We had 24. This year with ACE still only 96, the implication is 31 days at least 5F below the daily average. I still expect the La Nina warm signal to show strongly, but the cold wave signal is pretty strong. I'm expecting either one-two major cold waves or several smaller cold snaps. The lower ACE also implies locally "severely cold days" - 10F or more below daily average - should be around 12, instead of the projected 7 last year (we actually had 8 or 9 I believe).

The precipitation blend is still predominantly dry in the southern US, but much wetter than 2024-25.

Additionally, a lot of the hurricane seasons with near no to no activity in the Gulf end up pretty cold late - 2013-14, 2010-11, 1981-82, 1962-63, 2014-15, 2022-23 - if going into an El Nino or trending warmer in Nino 3.4 y/y. 

Great work Man ! 

[raindancewx]

I don't necessarily expect the cold to show up as severely as it does on those maps. It probably will come in warmer by 1-3F in two of the three months in Jan-Mar, and then as severe as depicted in the other(s). Taken verbatim the weighting would make Jan-Feb as cold almost as both 2014 and 2025 nationally, which is pretty unlikely. 

I also don't expect the WPO to flood Canada/Alaska with warm air all winter. If models are right the PDO/ENSO should move toward their warmer cycles and you should see a corresponding change in the Northern Hemisphere patterns. The 100-180W heat content at the equator down to 300m got to -1.33 last in Jan 2025 but is trending warmer/weaker this year, so you should see an easier breakdown of whatever the dominant pattern is late winter when the ocean heat content warms rapidly. It went all the way to -0.06 by March 2025. If we top out at -0.8 to -1.0 this year, the flip to 'warmth' that coincides with the surface pattern ENSO flips should happen a lot faster.

https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ocean/index/heat_content_index.txt

[GaWx]

13 minutes ago, raindancewx said:

I don't necessarily expect the cold to show up as severely as it does on those maps. It probably will come in warmer by 1-3F in two of the three months in Jan-Mar, and then as severe as depicted in the other(s). Taken verbatim the weighting would make Jan-Feb as cold almost as both 2014 and 2025 nationally, which is pretty unlikely. 

It’s too late, Raindance! I had just posted this at another BB:

 Those that follow Raindance know he’s well respected due to his pretty good record and very extensive research/detailed presentation. The highlight for the SE and nearby areas is a cold January that’s nearly as cold as Jan of 2025 (mainly 4-5 BN). This is a result of a 40% weighting of each of 2014, the coldest SE Jan since 1986, and the cold 2025.

 

[40/70 Benchmark]

Good stuff. Nice to see raindance posting. We seem to be generally on the same page, but he is a bit colder.

[raindancewx]

Forgot this. I have the counts for cold waves in the 80-120 ACE La Ninas locally.

For whatever reason, the tendency shows the low-solar, low ACE La Ninas seeing severe cold locally late (February) while the higher solar, low ACE, La Nina years see it early (Nov-Dec). So low solar Feb 1955/1985 have the most days 5F or more below average locally. But Dec 1971, Dec 1988, Nov 2000, Nov 2022 have far more solar activity. The years that go to El Ninos, 1971 and 2022, also see higher numbers of cold days in Nov-Dec locally in these La Ninas. My best guest is one big cold outbreak mid Nov-mid Dec for cold, and then smaller outbreaks later.

La Nina, 80-120 ACE

# Of Days by Month, AVG Temp 5F or colder than daily mean in ABQ
Year   Nov   Dec   Jan   Feb   Nov-Feb
1954    1         9      10      15     35
1971     6       15      8        5      34
1984    6        7      8       11       32
1988    9       11      9        5       34
2000   17       4     12       6       39
2022   14       5      5        7       31
Blend   9        9      8       8       34

# Of Days by Month, AVG Temp 10F or colder than daily mean in ABQ
Year   Nov   Dec   Jan   Feb   Nov-Feb
1954    0        3        3       12     18
1971     0        7        3       3      13
1984    2        3       4        7      16
1988    2        5       5        4      16
2000   10      0       3        0      13
2022    5       0       0        2       7
Blend   3       3       3        5      14

For July-June -

1954-55 is around 19 sunspots, 1984-85 is around 26.

1971-72 is about 101. 1988-89 is around 188. 2000-01 is around 163. 2022-23 is around 110.

2025-26 is probably lower than 2024-2025 (149) but still in the 1971, 2022, 2000, 1988 range.

[snowman19]

[anthonymm]

10 minutes ago, snowman19 said:

 

Here comes the screaming pac jet. All 3 winter months should be at least + 5 F for the nyc metro, plenty of -PNA, +NAO, cutters etc. Should be a massive winter for the west though. Wouldn't be surprised if Seattle racks up double whatever single digit number we get.

[GaWx]

52 minutes ago, anthonymm said:

Here comes the screaming pac jet. All 3 winter months should be at least + 5 F for the nyc metro, plenty of -PNA, +NAO, cutters etc. Should be a massive winter for the west though. Wouldn't be surprised if Seattle racks up double whatever single digit number we get. 

 Hey Anthony,

 The good news is that having all 3 winter months 5+ F warmer than normal is an extremely rare occurrence. Based on Central Park, 2001-2 at least came very close, but Feb may have barely missed if you use 1981-2010 climo. If you instead use 1971-2000 climo, it barely did it.

 Before 2001-2, you have to go all of the way back to 1931-2 to even come close. But Feb wasn’t warm enough and DQed it. The only one other than the possible 2001-2 is 1889-90. Even though it was 3F colder than 2001-2, the significantly colder Central Park climo of the late 1800s (slightly >3F colder) allowed it to clearly qualify.

 So, we definitely have 1889-90 and we may or may not have 2001-2. That’s it. So, it may have something like only a 1% underlying true probability.

https://www.weather.gov/wrh/Climate?wfo=okx

[anthonymm]

27 minutes ago, GaWx said:

 Hey Anthony,

 The good news is that having all 3 winter months 5+ F warmer than normal is an extremely rare occurrence. Based on Central Park, 2001-2 at least came very close, but Feb may have barely missed if you use 1981-2010 climo. If you instead use 1971-2000 climo, it barely did it.

 Before 2001-2, you have to go all of the way back to 1931-2 to even come close. But Feb wasn’t warm enough and DQed it. The only one other than the possible 2001-2 is 1889-90. Even though it was 3F colder than 2001-2, the significantly colder Central Park climo of the late 1800s (slightly >3F colder) allowed it to clearly qualify.

 So, we definitely have 1889-90 and we may or may not have 2001-2. That’s it. So, it may have something like only a 1% underlying true probability.

https://www.weather.gov/wrh/Climate?wfo=okx

In any event should be a shutout for snow because of the enso state. Like 22/23. Dec 22 was seasonable but a shutout for snow for the city because of the nina northerly storm track. The rest of the winter torched as we all know (warmest Jan-Feb on record).