2026-2027 Super El Nino

[GaWx]

 The newest BoM prog (dated April 11th) is unchanged and thus still has a RONI of +0.6 for April averaged out. This is almost certainly going to end up much too warm for April:

 

How do I know it is almost definitely going to bust much too warm for April?

 

Weekly RONI equivalent: 3rd column is 3.4

01APR2026         0.6       -0.3       -0.2        0.3
 08APR2026         1.0       -0.2       -0.3        0.2

https://www.cpc.ncep.noaa.gov/data/indices/rel_wksst9120.txt

 
 So, the weeks centered on April 1/April 8 were -0.2/-0.3.

 Here’s the current OISST, which isn’t relative and thus one needs to subtract ~0.5 from it:

 As the above chart shows, there’s been no net warming for the last 3 weeks and the latest few days of OISST have been only +0.05 to +0.15. Subtracting 0.5 gives ~-0.4 for the RONI equivalent. April 1-11 OISST are likely no warmer than ~-0.3 for RONI equiv. To be conservative in converting from OISST to ERSST, I’ll call it -0.2 for RONI MTD. The weeklies I showed suggest between -0.2 and -0.3. 
 

 How is it even possible for April RONI as a whole to come in anywhere near as warm as +0.6? These daily OISST readings (don’t forget these are not relative) would need to skyrocket to an avg of at least ~+1.5 for Apr 12-30!! And with OISST starting off at <+0.2, there are going to have to be some +2++ dailies starting no later than 2 weeks from now! Nothing even remotely close to that extremely rapid rate of warming has occurred on record. Thus, BoM is looking to bust much too warm for Apr RONI. With Apr being way off, the credibility of the rest of the run is compromised.

[40/70 Benchmark]

Let me preface this by admitting that I am still on my annual hiatus and won't begin really diving in until latter May/June....but I remain skeptical of an uber-strong El Nino. My larger concern is the continued lag between the RONI and the ONI being reflective of what will ultimately be a partial masking the warm ENSO, and thus a reduced north Pacific response, which would mean a less pronounced GOA low. I do not expect a result as dire as 2023 because we seem to have a changed longer-term WPO modes, but I would, nonetheless, like to see that delt between the RONI and ONI close with time.

[40/70 Benchmark]

On 4/10/2026 at 6:13 PM, Stormchaserchuck1 said:

Lack of understanding what ENSO is if it's constantly pointed out that Weak-Moderate is better than Strong+. I'm not talking about its orientation changing. It's funny how a few analogs can make people prisoner of expectation. 

Logic test: What's a super La Nina like? 

Weak-moderate is absolutely better than strong in my region.

[40/70 Benchmark]

On 4/10/2026 at 6:18 PM, Stormchaserchuck1 said:

What I find interesting about the global average temperature, is that it has gone exponential, when mostly La Nina's have occurred since 1998. 

Per RONI, 5 of the last 6 years (20-26) have been La Nina.  Per RONI, 7 of the last 10 years (16-26) have been La Nina.  Per RONI, 11 of the last 19 years (07-26) have been La Nina.   Per RONI, 15 of the last 28 years (98-26) have been La Nina. That's >50% La Nina since 1998. 

More than 50% of years have been La Nina since 1998. Had it been 33-33-33, global average temperature would have been higher over that time! The quick re-hit of Strong El Nino this year is going to push us back closer to the long term Neutral ENSO mark. 

It's because the warming of the western Pacific has outpaced eastern Pacific, which fosters a cool ENSO paradigm.

[40/70 Benchmark]

On 4/10/2026 at 11:28 PM, TheClimateChanger said:

Hmm, maybe because the old measurements are biased low? 

Snowfall measurement: a flaky history | NCAR & UCAR News

I see your point, but I have a couple counters that you neglect to consider. I know for a fact that modern snowfall measuring techniques are not homogeneous....secondly, while I do agree that the 6 hourly method does increase totals on average because it's actually measuring snowfall, which is different from to snow depth, there are some mixed precipitation events in which it will not. 

[GaWx]

Latest 10 day CFSv2 ensemble mean forecast of RONI: +2.0 peak OND. Note that unlike the BoM’s nearly impossible +0.6 for April, this has a much more sensible -0.3:

[michsnowfreak]

28 minutes ago, 40/70 Benchmark said:

I see your point, but I have a couple counters that you neglect to consider. I know for a fact that modern snowfall measuring techniques are not homogeneous....secondly, while I do agree that the 6 hourly method does increase totals on average because it's actually measuring snowfall, which is different from to snow depth, there are some mixed precipitation events in which it will not. 

Other than that one article that is shared over and over by the same people, we have no idea what went into measuring at every location pre-1950. I think actually 1948 is when the 6 hr started at airports. That is also when they started rounding up daily snow depth to nearest inch. I have done plenty of local research on past weather events and while human error was there in 1880 and is there in 2026, I am pretty confident in the snow record at Detroit (and most other 1st order stations) being quite accurate. Now, coops and NON first order, who knows and there are undoubtedly tons of error. 

Back in the 1800s and very early 1900s they would always say "10 inches of snow fell on the level" or something like that. They applied a 10-1 ratio usually. But it would make more sense to apply a 10-1 ratio to what you measured than to melt snow down for a liquid and apply the ratio to snow. Its a hell of a lot easier measuring snow than it is melting it down for liquid equivalent.

[BlizzardWx]

I know for my area we statistically do better with weak to moderate el nino, but if we need a strong nino to finally stir up the west pacific warm pool I will take it. I agree that this does not look like 2023 at this point, but its also real early and it would be silly to be too confident in any outcome yet. 

[mitchnick]

4 hours ago, GaWx said:

Latest 10 day CFSv2 ensemble mean forecast of RONI: +2.0 peak OND. Note that unlike the BoM’s nearly impossible +0.6 for April, this has a much more sensible -0.3:

The Bias Corrected version is "usually" closer to reality.

[mitchnick]

Weekly SSTA (just updated) for Enso 3.4 and 4 have been stuck at +.2C and +.6C respectively for the past 3 weeks. Looking forward to a month from now since we're still in a Niña hangover of sorts that should be wiped out by then.

https://www.cpc.ncep.noaa.gov/data/indices/wksst9120.for

[GaWx]

1 hour ago, mitchnick said:

Weekly SSTA (just updated) for Enso 3.4 and 4 have been stuck at +.2C and +.6C respectively for the past 3 weeks. Looking forward to a month from now since we're still in a Niña hangover of sorts that should be wiped out by then.

https://www.cpc.ncep.noaa.gov/data/indices/wksst9120.for

The latest official weekly for 3.4 was semi-stalled at -0.3 after being -0.2 the week before and -0.3 two weeks before:

https://www.cpc.ncep.noaa.gov/data/indices/rel_wksst9120.txt

[GaWx]

18 hours ago, snowman19 said:

 

 So far as regards the effects on Nino 3.4 SSTa, it’s been all bark and little or no bite with it still at ~-0.2 to -0.3C. It should resume warming shortly, but it’s done none the last 3 weeks.

[snowman19]

34 minutes ago, GaWx said:

 So far as regards the effects on Nino 3.4 SSTa, it’s been all bark and little or no bite with it still at ~-0.2 to -0.3C. It should resume warning shortly, but it’s done none the last 3 weeks.

Yea. ENSO events normally take time

[snowman19]

@Stormchaserchuck1 Wow at the current subsurface warmth. This downwelling Kelvin wave is massive. As per Paul Roundy: “The amount of momentum already integrated into this Kelvin wave has exceeded that of the March 1997 event by roughly 50%!”
 

[so_whats_happening]

Unfortunately had a large gap in data for TAO recently but here is the 2N-2S TAO depiction of the subsurface. Reminder that CPC and TAO are different in coverage but overall represent things similarly.

[so_whats_happening]

Here are some depictions for specific years in comparison to this year.

 

[so_whats_happening]

Just now, so_whats_happening said:

Here are some depictions for specific years in comparison to this year.

 

The depiction of the subsurface alone would make me think at this early stage we are further west than two of the  stronger Nino events in the last 30 years.

[40/70 Benchmark]

21 hours ago, GaWx said:

Latest 10 day CFSv2 ensemble mean forecast of RONI: +2.0 peak OND. Note that unlike the BoM’s nearly impossible +0.6 for April, this has a much more sensible -0.3:

What does it have for the ONI?

[bluewave]

23 minutes ago, 40/70 Benchmark said:

What does it have for the ONI?

Similar to the Euro which is what you would expect if these record WWBs continue past the spring forecast barrier.

 

[40/70 Benchmark]

7 minutes ago, bluewave said:

Similar to the Euro which is what you would expect if these record WWBs continue past the spring forecast barrier.

 

So 2.0 RONI and 2.5 ONI....not good.

I'll go torch if that remains consistent. I would rather see the RONI higher.

[George001]

On 4/13/2026 at 8:06 AM, michsnowfreak said:

Again, to be clear, im only doubting super at this point. It would be unheard of so close. Definitely a nino is coming.

Super would not be fun, but we always get winter in the great lakes. Thats a great thing about living here. You're rescued in the worst case scenarios. Our climate is less feast/famine. 

One thing that im liking is the persistent of the eastern trough in recent years. 

I do agree that northern areas aren’t necessarily doomed even if the Nino is on the stronger side, especially the great lakes (I know you guys do better in La Nina’s, but I do remember seeing somewhere that a super Nino is less of a death sentence for you guys than my area. I’d still prefer a weak or moderate event, but the early signs are this is developing more like recent strong or super ninos than the weak/moderate bucket. If it does become a super Nino I would go fairly aggressive on the mild and less snow side, but not necessarily if it is strong but not super and the non ENSO indicators look good (like you mentioned this is key, and is why this past winter was such a good one). Even last winter wasn’t an optimal ENSO configuration, and still was the best winter I had since 2014-2015. The east based nina idea like 17-18 and 21-22 didnt pan out, it shifted from more basin wide to a modoki Nina in the second half of winter. I recall looking in late Jan and being surprised at how much the coldest anomalies shifted west. We will see how things play out, id roll the dice with an 09-10 ENSO configuration with less blocking, so hopefully things break right in that regard. 

[40/70 Benchmark]

2023 would be my top analog, though probably not quite as warm and snowless given a bit more favorable of a look in the north Pacific.

[snowman19]

11 minutes ago, bluewave said:

Similar to the Euro which is what you would expect if these record WWBs continue past the spring forecast barrier.

 

This is starting to look like a lock for a “high-end” strong El Niño at the very minimum

[40/70 Benchmark]

Important to see how the PDO evolves, too.....I don't think that it will, but if it were to remain negative with the RONI continuing to lag to ONI, then good night nurse.

[bluewave]

9 minutes ago, 40/70 Benchmark said:

So 2.0 RONI and 2.5 ONI....not good.

I'll go torch if that remains consistent. I would rather see the RONI higher.

If the models are still showing something similar with the June updates, then our first 2.0°+ ONI El Niño events within 3 years would become more likely. 

[snowman19]

2 minutes ago, 40/70 Benchmark said:

Important to see how the PDO evolves, too.....I don't think that it will, but if it were to remain negative with the RONI continuing to lag to ONI, then good night nurse.

Given the totality of the indicators up to now, I think it goes super. Then the question becomes is it east-based/East Pacific (1997-98, 1982-83) or basin-wide (2015-16)

[snowman19]

“A strong MJO pulse (part of what helped spawn #Sinlaku) is traversing the Pacific and will move towards Central America. As a result, trade winds will slow across the Central and East Pacific in the next two weeks. I expect we will see some fairly rapid warming of ENSO 1+2 and ENSO 3 as a result, with a lot of sub-surface heat lurking from the last downwelling Kelvin Wave. On top of warming already ongoing, the East/Central Pacific may start to look very El-Niño-like shortly.”

[LakePaste25]

Interesting. 1972 was one of the coolest summers on record here.

 

[40/70 Benchmark]

1 hour ago, snowman19 said:

Given the totality of the indicators up to now, I think it goes super. Then the question becomes is it east-based/East Pacific (1997-98, 1982-83) or basin-wide (2015-16)

I know Chuck disagrees, but I don't think it matters much....it will be very warm. I think keeping it more west-focused, like 2015, just gives a better shot at a big storm and a cold interval or two.

[40/70 Benchmark]

Recall in January 2016 we had the big blizzard in January, and then a record arctic surge around V-Day.