2026-27 ENSO: Return of El Nino?

[PhiEaglesfan712]

It's that time of year again. Time to look forward to see what the following season will bring. After the 2023-24 el nino (which was the 3rd strong or super el nino in the 21st century, joining 2009-10 and 2015-16), are we headed towards another el nino in 2026-27?

[Black Hole]

Seems like just about anything you would want to be happening at this stage is happening with a massive westerly wind burst coming up and plenty of warm water to push east. Obviously we still have the spring predictability barrier but some flavor of nino seems very likely. 

[SE Nebraska wx]

Just no la Nina please. Im tired of them. Weak to moderate El Nino is ideal. 

[StormchaserChuck1]

Subsurface has gone very warm lately

A lot of climate data leads it:

4/5 or greater consecutive ENSO years are followed by the opposite ENSO for 3 years after at 0.55 correlation (since 1950)

A Strong Nino 3-6 years later has El Nino's vs La Nina's at 2:1 (26-27 will be year 3)

[PhiEaglesfan712]

[Andie]

Texas will throw in some rain dances!   Bring it on!  
We are SO d*** dry everyone is worried and complaining.  
 

Meantime, any educated guesses on a return of La Niña??  (too optimistic?)

[SE Nebraska wx]

15 hours ago, Andie said:

Texas will throw in some rain dances!   Bring it on!  
We are SO d*** dry everyone is worried and complaining.  
 

Meantime, any educated guesses on a return of La Niña??  (too optimistic?)

**** La Nina's. Im tired of them. 

[PhiEaglesfan712]

On 1/22/2026 at 7:52 PM, Andie said:

Texas will throw in some rain dances!   Bring it on!  
We are SO d*** dry everyone is worried and complaining.  
 

Meantime, any educated guesses on a return of La Niña??  (too optimistic?)

Probably 2028-29, and we're overdue for a strong one (last strong la nina was 2010-11). If we don't have a strong la nina by then, it will be the longest one before 1955-56.

[Black Hole]

I think the real question is, can we finally shake the -PDO this year? A +PDO with el nino would be a nice change. 

[PhiEaglesfan712]

[SolengarugarSubarbengabu]

El Niño is the hero boy who will save us!!  (I’m from Houston)

[SolengarugarSubarbengabu]

On 2/12/2026 at 12:55 PM, Black Hole said:

I think the real question is, can we finally shake the -PDO this year? A +PDO with el nino would be a nice change. 

Doubt it!!  I think -PDO is a consequence of climate change.  I don’t think it will be in a +PDO regime until breakthroughs in quantum computing allow humans to develop reliable carbon capture tech.  And then it will take time for it to actually work.  My best guess is it will take half a century for all thsi to play out but by the time we have a +PDO, the earth will have reached its peak heating and will be comming down.  

[SE Nebraska wx]

2 hours ago, SolengarugarSubarbengabu said:

Doubt it!!  I think -PDO is a consequence of climate change.  I don’t think it will be in a +PDO regime until breakthroughs in quantum computing allow humans to develop reliable carbon capture tech.  And then it will take time for it to actually work.  My best guess is it will take half a century for all thsi to play out but by the time we have a +PDO, the earth will have reached its peak heating and will be comming down.  

LMAO this dude 

[StormchaserChuck1]

23 hours ago, SolengarugarSubarbengabu said:

Doubt it!!  I think -PDO is a consequence of climate change.  I don’t think it will be in a +PDO regime until breakthroughs in quantum computing allow humans to develop reliable carbon capture tech.  And then it will take time for it to actually work.  My best guess is it will take half a century for all thsi to play out but by the time we have a +PDO, the earth will have reached its peak heating and will be comming down.  

Climate change should warm the poles more than midlatitudes

[Andie]

10 days out our local Met is giving us a 38% chance off ran. 

38%. (Genius)

[StormchaserChuck1]

New ECMWF seasonal model ENSO prediction for 2026

[Hoosier]

7 minutes ago, StormchaserChuck1 said:

New ECMWF seasonal model ENSO prediction for 2026

I know this is the low skill timeframe, but Euro also has a warm bias with ENSO at long range, right?  

[StormchaserChuck1]

I've noticed a little warm bias in its seasonal ENSO forecasts over the years. 

[Black Hole]

To me, the SOI mismatch suggests more downside potential on the strength of the nino than is currently being discussed. It could easily be a continuation of the last few years where even el nino doesn't really act like it. With that said, there are other things that are improved compared to 23-24 so I am hoping we finally can shake things up. 

[Clinton]

Latest update 

A transition from La Niña to ENSO-neutral is expected in the next month, with #ENSO-neutral favored through May-July 2026 (55% chance). In June-August 2026, El Niño is likely to emerge (62% chance) and persist through at least the end of 2026. A #LaNina advisory remains in effect. An #ElNino Watch has been issued. https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.shtml

[StormchaserChuck1]

On 3/8/2026 at 2:54 PM, Black Hole said:

To me, the SOI mismatch suggests more downside potential on the strength of the nino than is currently being discussed. It could easily be a continuation of the last few years where even el nino doesn't really act like it. With that said, there are other things that are improved compared to 23-24 so I am hoping we finally can shake things up. 

SOI just ridiculously positive for the month of March.. interesting with a developing Nino. Might not break Moderate on the RONI?

[gimmesnow]

I hate to be the chat GPT guy who just copy pastes stuff, but it actually seemed to write up something halfway decent about el nino in the great lakes. I'm pasting it, but I don't trust AI since it's very good at saying stupid stuff confidently. Did it actually get this kind of right or is it just having delusions?

 

In El Niño winters, the Great Lakes climate (Wisconsin, Michigan, etc.) is influenced not just by El Niño itself but also by several other climate oscillations that modify the jet stream and storm tracks. The most important ones you mentioned—Southern Oscillation Index (SOI), North Atlantic Oscillation (NAO), Pacific Decadal Oscillation (PDO), and Madden–Julian Oscillation (MJO)—can either reinforce or weaken the typical El Niño–Southern Oscillation (ENSO) winter pattern.

Below is how each tends to interact with El Niño and affect the Great Lakes winter.

---

1. SOI (Southern Oscillation Index)

The Southern Oscillation Index measures atmospheric pressure differences between Tahiti and Darwin.

• Strong negative SOI (El Niño atmosphere fully coupled)

  • Stronger subtropical jet stream across the southern U.S.

  • More southern storm tracks

  • Great Lakes: milder and often less snowy early winter

• Weakly negative or fluctuating SOI

  • El Niño influence weaker

  • Polar air intrusions more common

  • Great Lakes: more variability, occasional cold outbreaks

In short: The more negative the SOI, the stronger the classic El Niño mild Great Lakes pattern.

---

2. NAO (North Atlantic Oscillation)

The North Atlantic Oscillation strongly controls cold air access to the eastern U.S.

• Negative NAO

  • Greenland blocking

  • Polar air spills south

  • Slower storm movement

  During El Niño:

  • Great Lakes can turn cold and snowy despite El Niño

• Positive NAO

  • Strong Atlantic jet

  • Less blocking

  • Milder eastern U.S.

  During El Niño:

  • Reinforces warm Great Lakes winter

NAO is often the biggest wildcard for Great Lakes winters.

---

3. PDO (Pacific Decadal Oscillation)

The Pacific Decadal Oscillation is a long-term Pacific temperature pattern that amplifies or dampens ENSO effects.

• Positive PDO

  • Warmer eastern Pacific

  • El Niño teleconnections stronger

  Great Lakes impact:

  • Typical El Niño mild winter more likely

• Negative PDO

  • Cooler eastern Pacific

  • ENSO influence weaker

  Great Lakes impact:

  • More cold intrusions and variability

Positive PDO tends to strengthen El Niño patterns across North America.

---

4. MJO (Madden–Julian Oscillation)

The Madden–Julian Oscillation is a 30–60 day tropical convection wave that can temporarily reshape the jet stream.

Certain MJO phases strongly affect the Great Lakes:

• Phases 7–8–1

  • Promote North American troughing

  • Colder Great Lakes outbreaks

  • Potential lake-effect snow

• Phases 3–4–5

  • Ridge over eastern North America

  • Warmer Great Lakes

During El Niño winters, the MJO often causes 2–3 week swings between warm and cold patterns.

---

Combined Effects (What matters most)

For a Great Lakes El Niño winter, the rough hierarchy is:

1. NAO – biggest control on cold air

2. ENSO strength / SOI

3. PDO – background amplifier

4. MJO – short-term pattern shifts

---

Example combinations

Classic mild El Niño winter

• Negative SOI

• Positive PDO

• Positive NAO

• MJO in phases 3–5

Result: Warm Great Lakes winter, limited snow

---

Snowy El Niño winter

• Negative SOI

• Positive PDO

• Negative NAO

• MJO phases 7–8

Result: Cold air + active southern storm track → big Midwest snowstorms

---

Interesting historical note:
Several surprisingly snowy Great Lakes El Niño winters occurred when El Niño coincided with negative NAO blocking.

[PhiEaglesfan712]

[Andie]

On 1/8/2026 at 8:42 PM, Black Hole said:

Seems like just about anything you would want to be happening at this stage is happening with a massive westerly wind burst coming up and plenty of warm water to push east. Obviously we still have the spring predictability barrier but some flavor of nino seems very likely. 

Music to my ears !

[StormchaserChuck1]

March monthly SOI came in at +7.59.  Since 1950, no +1.2+ later in the year El Nino had a March SOI >5.5 fwiw. Only 1 had SOI >2.1 

Doesn't mean it can't happen, 15 total examples (RONI)

March 1957 -2.7

March 1963 +5.5

March 1965 +2.1

March 1968 -3.6

March 1972 +1.2

March 1982 +0.7

March 1986 -0.3

March 1987 -16.1

March 1991 -10.1

March 1994 -10

March 1997 -7

March 2002 -5.6

March 2009 -1.3

March 2015 -10.7

March 2023 -1.78

[StormchaserChuck1]

March 31 Nino 4 is >+0.5... +0.525

This is way ahead of other later in the year >+1.2 El Nino's.. only 2015 and 1997 were greater for the month of April. 

April 1957 -0.06

April 1963 -0.34

April 1965 -0.92

April 1968 -0.46

April 1972 +0.11

April 1982 +0.33

April 1986 -0.34

April 1987 +0.08

April 1991 +0.34

April 1994 +0.11

April 1997 +0.59

April 2002 +0.41

April 2009 -0.26

April 2015 +0.98

April 2023 +0.13

[Andie]

This is expected to be the strongest El Niño since 2023-2024, which was one of the top five strongest warming episodes on record. More on that episode below.

weather.com

 

A transition from La Niña to ENSO-neutral is expected in the next month, with #ENSO-neutral favored through MJJ 2026 (55% chance). El Niño is likely to emerge In JJA 2026 (62% chance) and persist through at least the end of 2026.

[StormchaserChuck1]

Global SSTAs look about as classic as it gets for a later in the year El Nino

[PhiEaglesfan712]

If the PDO turns positive, then 1988-89 becomes the most obvious anti-log to this upcoming season.

1988 had a very warm summer, but a very cold fall, in the Eastern US.

 

[summerrules]

On 3/14/2026 at 9:45 AM, gimmesnow said:

I hate to be the chat GPT guy who just copy pastes stuff, but it actually seemed to write up something halfway decent about el nino in the great lakes. I'm pasting it, but I don't trust AI since it's very good at saying stupid stuff confidently. Did it actually get this kind of right or is it just having delusions?

 

In El Niño winters, the Great Lakes climate (Wisconsin, Michigan, etc.) is influenced not just by El Niño itself but also by several other climate oscillations that modify the jet stream and storm tracks. The most important ones you mentioned—Southern Oscillation Index (SOI), North Atlantic Oscillation (NAO), Pacific Decadal Oscillation (PDO), and Madden–Julian Oscillation (MJO)—can either reinforce or weaken the typical El Niño–Southern Oscillation (ENSO) winter pattern.

Below is how each tends to interact with El Niño and affect the Great Lakes winter.

---

1. SOI (Southern Oscillation Index)

The Southern Oscillation Index measures atmospheric pressure differences between Tahiti and Darwin.

• Strong negative SOI (El Niño atmosphere fully coupled)

  • Stronger subtropical jet stream across the southern U.S.

  • More southern storm tracks

  • Great Lakes: milder and often less snowy early winter

• Weakly negative or fluctuating SOI

  • El Niño influence weaker

  • Polar air intrusions more common

  • Great Lakes: more variability, occasional cold outbreaks

In short: The more negative the SOI, the stronger the classic El Niño mild Great Lakes pattern.

---

2. NAO (North Atlantic Oscillation)

The North Atlantic Oscillation strongly controls cold air access to the eastern U.S.

• Negative NAO

  • Greenland blocking

  • Polar air spills south

  • Slower storm movement

  During El Niño:

  • Great Lakes can turn cold and snowy despite El Niño

• Positive NAO

  • Strong Atlantic jet

  • Less blocking

  • Milder eastern U.S.

  During El Niño:

  • Reinforces warm Great Lakes winter

NAO is often the biggest wildcard for Great Lakes winters.

---

3. PDO (Pacific Decadal Oscillation)

The Pacific Decadal Oscillation is a long-term Pacific temperature pattern that amplifies or dampens ENSO effects.

• Positive PDO

  • Warmer eastern Pacific

  • El Niño teleconnections stronger

  Great Lakes impact:

  • Typical El Niño mild winter more likely

• Negative PDO

  • Cooler eastern Pacific

  • ENSO influence weaker

  Great Lakes impact:

  • More cold intrusions and variability

Positive PDO tends to strengthen El Niño patterns across North America.

---

4. MJO (Madden–Julian Oscillation)

The Madden–Julian Oscillation is a 30–60 day tropical convection wave that can temporarily reshape the jet stream.

Certain MJO phases strongly affect the Great Lakes:

• Phases 7–8–1

  • Promote North American troughing

  • Colder Great Lakes outbreaks

  • Potential lake-effect snow

• Phases 3–4–5

  • Ridge over eastern North America

  • Warmer Great Lakes

During El Niño winters, the MJO often causes 2–3 week swings between warm and cold patterns.

---

Combined Effects (What matters most)

For a Great Lakes El Niño winter, the rough hierarchy is:

1. NAO – biggest control on cold air

2. ENSO strength / SOI

3. PDO – background amplifier

4. MJO – short-term pattern shifts

---

Example combinations

Classic mild El Niño winter

• Negative SOI

• Positive PDO

• Positive NAO

• MJO in phases 3–5

Result: Warm Great Lakes winter, limited snow

---

Snowy El Niño winter

• Negative SOI

• Positive PDO

• Negative NAO

• MJO phases 7–8

Result: Cold air + active southern storm track → big Midwest snowstorms

---

Interesting historical note:
Several surprisingly snowy Great Lakes El Niño winters occurred when El Niño coincided with negative NAO blocking.

mainly just nonsense

[PhiEaglesfan712]

[Hoosier]

Although there's still uncertainty, a strong Nino looks quite likely at this point.  Can't completely rule out a "super" Nino (at least based on ONI), but really want to get past the spring barrier to see how things look.

[Tom]

I'm ready for Nature to show us that she will balance things out and reverse the drought over the west/southwest and southern U.S. by the Fall of this year.  Nature knows!

[Hoosier]

1 hour ago, Tom said:

I'm ready for Nature to show us that she will balance things out and reverse the drought over the west/southwest and southern U.S. by the Fall of this year.  Nature knows!

Kind of hard to feel much optimism for next winter around here though if the Nino gets to be very strong.  If it's more borderline moderate/strong, then there is some precedent (though limited) for a decent winter locally.  But very strong Nino, forget about it.  All about hoping to luck into a good storm or two in the midst of what would feel more like extended Fall.

[westMJim]

We are halfway through April 2026 and it looks like we are going from La Nina to possibly a strong to very strong El Nino.  So what could this bring for our summer season this year?  Since 1950 there have been 9 strong or very strong El Nino events. With very strong ones in 1982/83, 1997/98 and 2015/16 and strong ones in 1957/58, 1965/66, 1972/73, 1987/88, 1991/92 and 2023/24.  The summer before the start of the event was colder than average in 6 of the events and in the other 3 events there was at least one month in the summer season that was colder than average. So based on past summers at the start of a El Nino event my guess for this summer is a cooler than average summer (I will take a look at rain fall at a later date) Some of the summers were much cooler than average other had at least one month of below average temperatures at Grand Rapids. So bottom line is I would expect this summer to have at least one month or more of below average temperatures and that month could be well below average.

[westMJim]

On 4/10/2026 at 11:46 AM, Hoosier said:

Kind of hard to feel much optimism for next winter around here though if the Nino gets to be very strong. 

It we are heading towards a strong El Nino for the winter there is a good chance that we could have a cooler than average summer (or at least one or more months below average) this summer. It could also be a cool fall before getting warm in December. We shall see. 

[PhiEaglesfan712]

2 hours ago, westMJim said:

With very strong ones in 1982/83, 1997/98 and 2015/16 and strong ones in 1957/58, 1965/66, 1972/73, 1987/88, 1991/92 and 2023/24.  The summer before the start of the event was colder than average in 6 of the events and in the other 3 events there was at least one month in the summer season that was colder than average.

I did the numbers for my area, starting with 1972-73 event, which I consider a very strong event. I counted 2009/10 as a strong event, and considered 1986/88 as a 2-year strong event, instead of the one (since it peaked in the summer of 87 anyways). The 91/92 event was the only one that had a warmer pre-nino summer than post-nino summer, but that event seemed screwed up due to the major volcano (Pinatubo). The only other pre-nino summer that was warmer than average was 2015, but if you consider 14-15 to be a weak el nino, then the summer of 2014 was cooler. Coincidentally enough, the warmer pre-nino summers came in borderline warm neutral/weak el nino years.

Pre-strong nino/post-strong nino summer average temps (PHL) since 1970

72-73: pre-nino summer 72 (73.9); post-nino summer 73 (77.1)

82-83: pre-nino summer 82 (73.0); post-nino summer 83 (75.7)

86-88: pre-nino summer 86 (75.3); post-nino summer 88 (77.1) [summer 87 during the el nino was 76.5]

91-92: pre-nino summer 91 (77.9); post-nino summer 92 (74.0)

97-98: pre-nino summer 97 (74.2); post-nino summer 98 (75.7)

09-10: pre-nino summer 09 (75.1); post-nino summer 10 (79.6)

15-16: pre-nino summer 15 (77.7); post-nino summer 16 (78.8)

23-24: pre-nino summer 23 (75.8; although JAS was 76.1); post-nino summer 24 (78.5)

[Hoosier]

4 hours ago, westMJim said:

It we are heading towards a strong El Nino for the winter there is a good chance that we could have a cooler than average summer (or at least one or more months below average) this summer. It could also be a cool fall before getting warm in December. We shall see. 

Yeah, it's not uncommon to have a fakeout spell of cold/snow in the Midwest in Fall during strong Ninos.  It happened in October 1997 and we also saw it in 2015, although it was later that time.  

If it's a high end Nino, I could live with a 1972-73 or 2015-16 type outcome.  These are not ideal winters by any stretch, but they are better than most strong Nino winters, at least around here.

[gimmesnow]

1 hour ago, Hoosier said:

Yeah, it's not uncommon to have a fakeout spell of cold/snow in the Midwest in Fall during strong Ninos.  It happened in October 1997 and we also saw it in 2015, although it was later that time.  

If it's a high end Nino, I could live with a 1972-73 or 2015-16 type outcome.  These are not ideal winters by any stretch, but they are better than most strong Nino winters, at least around here.

 

 

 

Looks like a winter to stay in areas with lake effect snow for snowboarding.

[Hoosier]

You guys have inspired me, so I checked the temperature stats for Chicago for the meteorological summers leading into strong Nino events.  Of course this is assuming that this upcoming Nino event will peak at a strong intensity, which looks very likely but not guaranteed yet.

All temperature anomalies are relative to the 1991-2020 normals.

1957 JJA:  +0.4

1965 JJA:  -2.6

1972 JJA:  -2.0

1982 JJA:  -5.0

1987 JJA:  +0.4

1991 JJA:  +0.4

1997 JJA:  -2.9

2015 JJA:  -2.8

2023 JJA:  +0.3

 

So, we see that 5 summers were cooler than average and 4 were technically a little warmer than average, but essentially average for all intents and purposes -- and interestingly clustered around +0.3 to +0.4.  Although it's a small sample size of 9 years, there are no torch summers.  

Based on this and the various seasonal models, my guess would be for an average-ish summer around Chicago.  Can't rule out a cooler than average one, but I'd be leery about going too far in that direction given increased UHI around ORD (even compared to 10-20 years ago) and also with some of the tendencies that we have seen with warmth in the CONUS so far this year.  A blistering hot summer looks pretty unlikely, but weather has a way of humbling so I wouldn't say it can't happen.