2026-2027 Strong/Super El Nino

[GaWx]

More on the BoM warm bias: We remember how bad it was in 2023. But also: only 2 weeks ago, it had ~+1.15C for May (see image below) vs the latest’s only ~+0.55C in the image I posted in the previous post! It’s been doing this for 2 months and that’s the kind of thing it kept doing in 2023. We’re still likely headed for a super-Nino, but very likely not as warm as the RONI based ~+3.0C 3 month average super-super Nino the BoM is showing. It could easily be 0.5C too warm based on April/May and based on it being ~0.75C too warm based on forecasts from around this point in 2023:

[snowman19]

 

“Getting this sort of MJO-driven reinforcement of the developing #ElNiño with a massive westerly wind burst is a pretty good indicator that this event is going to be a very strong one. No sustained easterlies to interrupt the last Kelvin Wave, and this next WWB should push the warm pool even further east. Probably why even the *relative* SST anomalies are pushing 3-3.5C in some of the latest forecasts.”

 

 

 

[Stormchaserchuck1]

Good run of -SOI.. we could make a run at most negative 2-month period (Apr-May '26) since 2016

25 May 2026	1011.06	1012.85	-25.41	-12.61	-3.54
24 May 2026	1010.19	1012.80	-31.69	-12.71	-3.18
23 May 2026	1011.70	1012.55	-18.21	-12.02	-2.76
22 May 2026	1012.15	1013.20	-19.74	-11.50	-2.49
21 May 2026	1010.85	1013.05	-28.55

[snowman19]

1 hour ago, Stormchaserchuck1 said:

Good run of -SOI.. we could make a run at most negative 2-month period (Apr-May) since 2016

25 May 2026	1011.06	1012.85	-25.41	-12.61	-3.54
24 May 2026	1010.19	1012.80	-31.69	-12.71	-3.18
23 May 2026	1011.70	1012.55	-18.21	-12.02	-2.76
22 May 2026	1012.15	1013.20	-19.74	-11.50	-2.49
21 May 2026	1010.85	1013.05	-28.55

Massive +AAM spike coming and an El Nino standing wave is developing. It’s absolutely coupling (ocean-atmosphere) and coupling strongly

 

 

 

 

 

 

 

 

 

 

 

Per Paul Roundy we are about to pull ahead of 1997

 

 

 

 

 

 

[Stormchaserchuck1]

Just not really seeing the corresponding pressure patterns in the North and South Pacific so far, in the mid latitudes. 

1997 and 1982: notice how -SLP stretched in the Hadley Cell from 180E to 360E

[snowman19]

7 hours ago, Stormchaserchuck1 said:

Just not really seeing the corresponding pressure patterns in the North and South Pacific so far, in the mid latitudes. 

1997 and 1982: notice how -SLP stretched in the Hadley Cell from 180E to 360E

How do you explain the +AAM, -SOI, convective (low frequency) standing wave, WWBs/westerlies, raging STJ? Those are all blatant Nino atmospheric coupling responses

[Stormchaserchuck1]

Why do you think the PNA and Southern Hemisphere High pressure is not responding so far? The same thing happened in 23-24. There's definitely an El Nino building in many aspects, but it's not propagating to the northern and southern latitudes as much as past examples, thus far, not a global dominating event.  The +AAM should produce more of a northern latitude favorable H5 pattern, let's see what happens there in the next few weeks. 

[LakePaste25]

54 minutes ago, Stormchaserchuck1 said:

Why do you think the PNA and Southern Hemisphere High pressure is not responding so far? The same thing happened in 23-24. There's definitely an El Nino building in many aspects, but it's not propagating to the northern and southern latitudes as much as past examples, thus far, not a global dominating event.  The +AAM should produce more of a northern latitude favorable H5 pattern, let's see what happens there in the next few weeks. 

Yup but I’m still taking a wait and see approach because it can still respond between now and Oct. Zero complaints if I end up with a more Nina-like summer and it’s hotter and less rainy. 

[roardog]

How high did the AAM get in 2023? I wouldn’t be surprised if we see more of a response across the North Pacific as we go deeper into June if the forecasts for the rising AAM verify. 

[roardog]

1 hour ago, Stormchaserchuck1 said:

Why do you think the PNA and Southern Hemisphere High pressure is not responding so far? The same thing happened in 23-24. There's definitely an El Nino building in many aspects, but it's not propagating to the northern and southern latitudes as much as past examples, thus far, not a global dominating event.  The +AAM should produce more of a northern latitude favorable H5 pattern, let's see what happens there in the next few weeks. 

RONI is barely into Nino and we still have a -PDO. Maybe it’ll take a little time yet.

[Stormchaserchuck1]

I guess I've been harping on it a little much, you're right it's still early. If the AAM goes over +3, that's impressive and more of a -NPH signal for the rest of the year imo. It will be interesting to see what actually happens after that, as the AAM tends to see-saw between positive and negative bouts, about every 35-40 days. 

[jaxjagman]

Has there ever been a ENSO maybe comparable to this on other than maybe 2009?Even this WWB upcoming is seemingly going to combatted more or less with a EWB

[GaWx]

4 hours ago, roardog said:

How high did the AAM get in 2023? I wouldn’t be surprised if we see more of a response across the North Pacific as we go deeper into June if the forecasts for the rising AAM verify. 

1. 2023 never got close to a +3 as far as I know.

2. Prior to today’s 0Z run, the highest CFSv2 progged peak mean I can recall seeing is this that I saved from 12/11/2023, which had 2 getting to +3 amp and the other 2 to +2 amp with a peak mean of ~+2.45:

 

3. However, this run turned out to be way off as just 6 days later it had this, a progged peak of only ~+1.45 and actual peak was only in the low +1s from other runs I saved:

 

4. Today’s 0Z by a good margin had the highest progged mean that I’m aware of any run I’ve seen because otherwise I would have saved them: insane progged peak probably (since can’t see green member peak) ~+3.5!!

 

5. But the newest run (12Z) came back to Earth quite a bit from the insane +3.5 although it’s still progging a potent peak at +2.3, which is still the 3rd highest progged peak I’ve saved:

 

6. Keep in mind that the first time I had seen these charts wasn’t til 2023. Thus I have no idea what it peaked at in prior strong El Niños.

7. Keep in mind that while I like to follow this guidance, it is the CFSv2. So, although well worth following, always take with a grain, especially out 2 weeks+!

@Stormchaserchuck1

@snowman19

[roardog]

1 hour ago, jaxjagman said:

Has there ever been a ENSO maybe comparable to this on other than maybe 2009?Even this WWB upcoming is seemingly going to combatted more or less with a EWB

I’m not as educated on some of this enso stuff as a lot of you guys are so I didn’t say anything but I was thinking the same as you just said. I feel like 2023 didn’t have that but I could be wrong. 

[snowman19]

^ “I have a feeling after this upcoming WWB, we're going to see the atmosphere-ocean system in a very classic-looking El Niño state. Increased easterly anomalies across the Indian Ocean will probably also shift things to a more +IOD state.

EPS weeklies have an extremely classic-looking El Niño standing wave setting up, with rising motion across the East/Central Pacific and sinking air across the Atlantic, Africa, and the Indian Ocean.

Also, the EPS weeklies show above-normal westerly shear across the Atlantic for the entire 6-week forecast. Even brief Kelvin waves/MJO passages don't really seem to break that. The windows for Atlantic tropical development this year may be few and far between.”
 

 

[40/70 Benchmark]

14 hours ago, Stormchaserchuck1 said:

I guess I've been harping on it a little much, you're right it's still early. If the AAM goes over +3, that's impressive and more of a -NPH signal for the rest of the year imo. It will be interesting to see what actually happens after that, as the AAM tends to see-saw between positive and negative bouts, about every 35-40 days. 

I don't think so....pretty much the key to next winter IMHO.

[bluewave]

On 5/21/2026 at 9:20 PM, BlizzardWx said:

The last few years we've done that mid summer PDO nosedive. I think that will be an early clue for this winter for what path we are on. If we can avoid driving off the PDO cliff maybe things really are changing.

 

Main issue has been the 500mb ridge east of Japan warming the SSTs below. So even though we have sufficient warming in the EPAC with the record +PMM, the warm pool under the ridge east of a Japan brings down the PDO.

Long range models like the CFS have struggled with this ridge in their forecasts. So like we saw last summer, the actual readings verified significantly lower.

FWIW, the CFS continues with the -PDO at least into early next winter due to the warm pool and ridging east of Japan persisting.
 

 

 

[40/70 Benchmark]

23 minutes ago, bluewave said:

Main issue has been the 500mb ridge east of Japan warming the SSTs below. So even though we have sufficient warming in the EPAC with the record +PMM, the warm pool under the ridge east of a Japan brings down the PDO.

Long range models like the CFS have struggled with this ridge in their forecasts. So like we saw last summer, the actual readings verified significantly lower.

FWIW, the CFS continues with the -PDO at least into early next winter due to the warm pool and ridging east of Japan persisting.
 

 

 

I wonder if the eastern Pacific playing a bit of catch up has helped the northern Pacific get more favorable over the last couple of years, which helps more with respect to cold than snow, as we still have the issue of the stronger jet to contend with. We need to find a way to cool the west Pacific to mitigate that.

[40/70 Benchmark]

On 5/24/2026 at 7:44 PM, MarcmmKU said:

Very hard to escape -pna now. Was kinda a miracle this last winter was better in that regard.

No it wasn't. It was clear as day that January would be +PNA at several months lead time if you knew what to look for.

[bluewave]

1 hour ago, 40/70 Benchmark said:

I wonder if the eastern Pacific playing a bit of catch up has helped the northern Pacific get more favorable over the last couple of years, which helps more with respect to cold than snow, as we still have the issue of the stronger jet to contend with. We need to find a way to cool the west Pacific to mitigate that.

Yeah, the PDO was able to be positive during the 1995-1996 weak La Niña winter. This weak La Niña winter had the ridges and troughs in the same general locations.

But notice how the ridges this winter were so much stronger leading to the much warmer CONUS and less snowy outcome than 1995-1996. We can see the ridge extension to the east of a Japan during DJF preventing the PDO from going positive.

Plus the more volatile NAO these days didn’t allow the -NAO to persist into the spring like we had back in 1995-1996. So March turned out to be a reversion to the warmer and less snowy 2020s mean. 
 

 

 

 

 

 

 

[snowman19]

If this is correct, we would smash the current RONI record (1982-83) by an entire degree. It would also smash the traditional ONI record….

EDIT BY LEON:
 

[GaWx]

54 minutes ago, snowman19 said:

If this is correct, we would smash the current RONI record (1982-83) by an entire degree. It would also smash the traditional ONI record….
 

What a sloppy Tweet by Leon Simons! He said:

“The Relative Oceanic Niño Index (RONI) forecast mean is now touching 3.5°C!”

 No, it isn’t. ONI is, not RONI. He then posted the latest ONI, which peaks at ~+3.5C in OND, instead of RONI. RONI actually peaks at ~+2.77C in OND as per this image:

[Stormchaserchuck1]

CFS has an extreme trend bias. It runs daily so you can find some big runs in there sometimes. The last few La Nina's it had peaks in the Mod-Strong ONI range on a few dailies. 

[Maxim]

On 5/25/2026 at 6:20 AM, bluewave said:

Most of the guidance missed the record 100° heat last week from the long range guidance earlier in the month. Models don’t do very well with extremes beyond the week one and week two forecast periods.

My guess is that the guidance beyond 15 days just reverts to whatever ENSO climo applies to the situation. In this case it was the usually cooler May climo it was forecasting to continue.

So it missed the strong MJO 4-6 pulse which is very warm in the East. This was also why the Euro and other seasonal models missed the warmth in the East for the 2023-2024 super El Niño. They had the stock El Niño composite with a deep trough in the East.

Instead we got the record MJO 4-6 pulse with the more Niña-like January 2024 even with the recent +2.1 ONI in Nino 3.4. So the long range model forecasts were reverting to the typical El Niño 500mb composite. 

Something similar happened in December 2015 with the long range model forecasts missing the record warmth in the East due to the record MJO 5. 

So long range models like to forecast just for whatever the ENSO is and they can’t resolve the MJO activity in the IO to WPAC. The record warm pool there has been resulting in more frequent and stronger MJO 4-7 activity than the old days when the SSTs were significantly cooler there. 
 

 

If I recall correctly, something similar happened in Feb 2024 when models were predicting a snowy and cold outcome most of the Midwest/East, but instead ended up being a legendary torch month with Fargo putting up an insane +17.5° departure. Though I can’t remember why exactly the cold/snowy forecasts busted so bad. Not sure if it was MJO related, but it was the warmest Feb on record for numerous cities, including my own. I do know the pac jet extension at the time was ridiculous, so that played a role surely.

[snowman19]

[40/70 Benchmark]

20 hours ago, snowman19 said:

If this is correct, we would smash the current RONI record (1982-83) by an entire degree. It would also smash the traditional ONI record….

EDIT BY LEON:
 

I love how you mock those on Social Media who dare to suggest that the ONI may not top 2.5, and then quote a dude suggesting that his incorrect interpretation of the RONI forecast could trigger "dystopian global climate change impacts over the next 1.5 years".

'Cmon, Adam...you're better than that.

[snowman19]

“The CFS continues to trend upward in even *relative* Nino 3.4 signals with new initial conditions in spite of relatively little westerly wind stress forcing, as the model initial conditions better integrate the subsurface ocean state in response to westerly wind forcing already integrated into the ocean system.

The relative index fixes a real problem of the warming of the global tropical ocean, but it also shrinks the scale of Nino 3.4 events beyond that because the relative index includes signal driven by ENSO itself.”

[michsnowfreak]

10 hours ago, Maxim said:

If I recall correctly, something similar happened in Feb 2024 when models were predicting a snowy and cold outcome most of the Midwest/East, but instead ended up being a legendary torch month with Fargo putting up an insane +17.5° departure. Though I can’t remember why exactly the cold/snowy forecasts busted so bad. Not sure if it was MJO related, but it was the warmest Feb on record for numerous cities, including my own. I do know the pac jet extension at the time was ridiculous, so that played a role surely.

Feb 2024 was NOT forecast to be a cold month in the midwest.

https://www.climate.gov/sites/default/files/styles/full_width_620_original_image/public/2024-02/Feb2024_tempoutlook.gif?itok=NFbaJvRE

[40/70 Benchmark]

36 minutes ago, michsnowfreak said:

Feb 2024 was NOT forecast to be a cold month in the midwest.

https://www.climate.gov/sites/default/files/styles/full_width_620_original_image/public/2024-02/Feb2024_tempoutlook.gif?itok=NFbaJvRE

Yea, I was thinking the same thing. That was supposed to be a mild winter that ended up even milder than expected.

[michsnowfreak]

26 minutes ago, 40/70 Benchmark said:

Yea, I was thinking the same thing. That was supposed to be a mild winter that ended up even milder than expected.

Exactly. The mean winter temp departures were very impressive considering it was all Dec/Feb. January was a decent winter month.