2026-2027 Record-breaking El Nino

[Terpeast]

35 minutes ago, mitchnick said:

Average for last 5 days ending 384 hours off the 0z Geps fwiw.

At least its showing up on modeling, now lets see if it actually verifies. 

[GaWx]

OHC monthly rose to a new record high that last month had set (note these aren’t adjusted for GW in a “relative” sense, but they’re still very impressive):

2025   11    -0.02     -0.33      -0.46
2025   12     0.26      0.01      -0.03
2026    1     0.64      0.45       0.49
2026    2     1.08      1.02       1.15
2026    3     1.38      1.39       1.36
2026    4     1.85      2.07       2.24
2026    5     1.67      1.97       1.99
2026    6     1.79      2.14       2.26
2026    7     2.03      2.50       2.96
2026    8     2.19      2.75       3.20

 The following image is for the same longitudes as that for the 3rd column and it jibes fairly well:

Prior to 2026, this had been the record high for the last 2 columns:

1997   10     1.35      2.05       2.56

[GaWx]

 The new relative OISST (not ERSST) has just been released and the change from July jibes well for Nino 3.4 with the slope of the graphs we’ve been following (though as I’ve also been saying the weeklies/last 2 months are notably cooler than what the cyclonicwx graphs have been suggesting).

2026    7      2.84     1.73     0.34      1.38
2026    8      3.35     2.52     0.11      1.78

https://www.cpc.ncep.noaa.gov/data/indices/rel_mthsst9120.txt
 
  This 1.78 is a new record high (back to 1981) for August Nino 3.4 as it barely beats the 1.74 of 1997. Here are the warmest Augusts since 1981:

2026 1.78
1997 1.74
2015 1.30
1987 1.24
1982 1.19
1991 0.82
2002 0.80
1994 0.72
2004 0.71
2023 0.63

 Note that Nino 3 rose twice as much and Nino 4 fell 0.23! Also, Nino 1+2 rose the 2nd most at 0.51. All of this indicates that this Nino has been becoming increasingly E based and that the W portion of Nino 3.4 is what is holding it back vs what model projections had been.

 Also, note that Nino 3.4 rose only 0.4C from the July avg to the Aug avg. I say “only” because several models were suggesting (as I’ve posted about several times) a record rapid rise for 3.4 of ~1C. It remains to be seen what the rise was per ERSST, but it’s clear that August didn’t warm nearly as much in 3.4 as model consensus had suggested, which has caused some at least near-term cooling of progs in some models’ recent runs.

 Here’s the latest OISST relative 3.4 chart through Sept 1st: STILL no sign of resumption of warming with it practically flat the last 31 days!

 

The CDAS (not relative) agrees with the continuing flatness:

[GaWx]

To add to the above, here are Nino 3 and Nino 4 (note that these aren’t relative, but that’s ok since my point is to show the slopes):

Nino 3: still a slow rise through Aug instead of nearly flat like 3.4:

Nino 4: had been falling through Aug 17th though a bumpy net slow rise since:

[MJO812]

7 hours ago, qg_omega said:

Record warmth summer and winter 

Screenshotted

[Stormchaserchuck1]

6 hours ago, 40/70 Benchmark said:

@Stormchaserchuck1

Thanks! They don't have SST so I will still have to find something for May-Sept N. Atlantic SSTA index. 

Here's that arctic -H5 for the warm season this year

90N.. just where my reverse correlation for the Winter is the highest. Expect 90N H5 ridging for the DJFM mean. 

[Stormchaserchuck1]

2 hours ago, mitchnick said:

Average for last 5 days ending 384 hours off the 0z Geps fwiw.

Yeah.. better models don't really show it. 30 days until the correlation increases by 3-4x!

[LakePaste25]

1 hour ago, GaWx said:

 The new relative OISST (not ERSST) has just been released and the change from July jibes well for Nino 3.4 with the slope of the graphs we’ve been following (though as I’ve also been saying the weeklies/last 2 months are notably cooler than what the cyclonicwx graphs have been suggesting).

2026    7      2.84     1.73     0.34      1.38
2026    8      3.35     2.52     0.11      1.78

https://www.cpc.ncep.noaa.gov/data/indices/rel_mthsst9120.txt
 
  This 1.78 is a new record high (back to 1981) for August Nino 3.4 as it barely beats the 1.74 of 1997. Here are the warmest Augusts since 1981:

2026 1.78
1997 1.74
2015 1.30
1987 1.24
1982 1.19
1991 0.82
2002 0.80
1994 0.72
2004 0.71
2023 0.63

 Note that Nino 3 rose twice as much and Nino 4 fell 0.23! Also, Nino 1+2 rose the 2nd most at 0.51. All of this indicates that this Nino has been becoming increasingly E based and that the W portion of Nino 3.4 is what is holding it back vs what model projections had been.

 Also, note that Nino 3.4 rose only 0.4C from the July avg to the Aug avg. I say “only” because several models were suggesting (as I’ve posted about several times) a record rapid rise for 3.4 of ~1C. It remains to be seen what the rise was per ERSST, but it’s clear that August didn’t warm nearly as much in 3.4 as model consensus had suggested, which has caused some at least near-term cooling of progs in some models’ recent runs.

 Here’s the latest OISST relative 3.4 chart through Sept 1st: STILL no sign of resumption of warming with it practically flat the last 31 days!

 

The CDAS (not relative) agrees with the continuing flatness:

1+2 has been marching back upward and the 20C isotherm in the subsurface itself has still been pressing deeper in the 1+2 region (i can’t show the GIF here due to file size limits), so if anything it’s been getting even more east-based despite Nino 3.4 flattening. I am keeping an eye out for a sudden jump in 3.4 because of this. 

 

 

[mitchnick]

31 minutes ago, Stormchaserchuck1 said:

Yeah.. better models don't really show it. 30 days until the correlation increases by 3-4x!

If you're referring to the Eps, I agree. Except you can see a dip in the height lines in the GOA not too far from the one on the Geps. Suggesting maybe it might be showing some blue in the GOA in future runs....OK, look real hard then! Lol

[Terpeast]

1 hour ago, LakePaste25 said:

1+2 has been marching back upward and the 20C isotherm in the subsurface itself has still been pressing deeper in the 1+2 region (i can’t show the GIF here due to file size limits), so if anything it’s been getting even more east-based despite Nino 3.4 flattening. I am keeping an eye out for a sudden jump in 3.4 because of this. 

 

 

It will be interesting to see how the negative PDO interacts with the east based nino. Historically east based isn’t good for us, especially if the PDO is positive because too strong of a GOA low would flood the continent with mild air cutting off any polar flow. How will the negative PDO interacts with that is the big question. GOA low still amplified with a stronger jet further north? Or weaker and further west low that allows polar air to move south? I think we’re in uncharted territory and the analogs can only do so much here. 

[Stormchaserchuck1]

28 minutes ago, Terpeast said:

It will be interesting to see how the negative PDO interacts with the east based nino. Historically east based isn’t good for us, especially if the PDO is positive because too strong of a GOA low would flood the continent with mild air cutting off any polar flow. How will the negative PDO interacts with that is the big question. GOA low still amplified with a stronger jet further north? Or weaker and further west low that allows polar air to move south? I think we’re in uncharted territory and the analogs can only do so much here. 

I understand that has happened in the past, but I would still prefer a +PDO in east-based Nino. Remember that correlates with warm water in the GOA and off the West Coast. 

PDO is further west than east-based Nino position, and doesn't necessarily only fuel it. It can shift things a bit west if strong enough

Some of the east-based Nino composite is warm in the NE because of +NAO (which is a more random part - if anything warmer 10mb in +ENSO may slightly favor -nao over a large enough sample). 

Jan 1998 is an anomaly, but I'm willing to say if that upper latitude pattern happens 10 times in east-based Nino it's cold in the east 8/10. Some times things just don't line up like they usually do.  See Dec 2022 and March 2023 as 2 good examples of that. It's only because the correlation isn't 100%. 

[40/70 Benchmark]

9 hours ago, mitchnick said:

Well, by the shadings, it hasn't in the past been nailing any areas. But has been doing better in some areas over others. For example, last year it did well in parts of the MW, NE, and MA while missing out west. Plus, the bottom map is an average over the last 30 years from what I'm seeing; probably the top one too. I wonder how accuracy would change if only looking back the last 5 years when there are obviously improvements with modeling.

I don't know about you, but there is an obvious concerted effort by the CC monetaryists, if I may call them that, to poo-poo any seasonal forecast that isn't a wall-to-wall Conus toaster oven. And I  would put Jonathan Wall into that category based on the 100+ posts he's made that have shown up on this Board.

Nobody knows with certainty how this winter will play out other than odds definitely favor AN in many areas of the Conus. But efforts to contradict/attack seasonal modeling are always a red flag to me.

I don't know Wall, so I'll take your word for it. I think most on this board would agree that my only agenda is getting the forecast correct, and placing much stock into a model with such a poor initialization of the Pacific basin, both ENSO and extra tropical, gives me significant pause before seriously considering it's output. This isn't about CC, or how well the model did last year....it's about the fact that it has such an obviously poor read on the Pacific.

[40/70 Benchmark]

What I can tell you based on what has been happening for the past decade is that the error is likely to be guidance underestimating the scope and magnitude of that Canadian ridge, so it's probably safe to assume that the greater heights will extend further to the south and east than most guidance suggests.....which combined with the poor read on the Pacific makes me very suspicious of that trend to shove the lower heights northward on the CANSIPS. 

This isn't me saying awful winter....I don't think, or want that to be the case, but that doesn't mean that I'm going to don my Frosty the Snowman boxers every time that I post.

[Stormchaserchuck1]

Since the El Nino developed in April, it's been a clear mid-latitude ridging pattern under 90N +AO. That's been the dominant pattern - not anything coming from the Tropics

I'm going to repeat this post, the pattern has been following itself closely, not anything in the historical analog dataset. 

Similarities to 2025 over the past 5 months:

2025 Apr-July 4/4 months -PNA
2026 Apr-July 4/4 months -PNA

2025 Aug +PNA
2026 Aug +PNA

2025 Apr-Aug 5/5 months +AO
2026 Apr-Aug 5/5 months +AO

[40/70 Benchmark]

5 minutes ago, Stormchaserchuck1 said:

Since the El Nino developed in April, it's been a clear mid-latitude ridging pattern under 90N +AO. That's been the dominant pattern - not anything coming from the Tropics

I'm going to repeat this post, the pattern has been following itself closely, not anything in the historical analog dataset. 

Similarities to 2025 over the past 5 months:

2025 Apr-July 4/4 months -PNA
2026 Apr-July 4/4 months -PNA

2025 Aug +PNA
2026 Aug +PNA

2025 Apr-Aug 5/5 months +AO
2026 Apr-Aug 5/5 months +AO

Yea, someone in the New England forum was trying to tell me were going to have a -PNA this winter...I was like, find a super El Niño that pulled that off.

-AO/+PNA means you can essentially eliminate the bottom dwelling seasons....even 1972 didn't. Now, maybe it will be bootleg, etc...but the season will average +PNA in the DJFM mean.

 

[Stormchaserchuck1]

18 minutes ago, 40/70 Benchmark said:

What I can tell you based on what has been happening for the past decade is that the error is likely to be guidance underestimating the scope and magnitude of that Canadian ridge, so it's probably safe to assume that the greater heights will extend further to the south and east than most guidance suggests.....which combined with the poor read on the Pacific makes me very suspicious of that trend to shove the lower heights northward on the CANSIPS. 

This isn't me saying awful winter....I don't think, or want that to be the case, but that doesn't mean that I'm going to don my Frosty the Snowman boxers every time that I post.

I don't think the SE, US will be below average temps like a lot of historical analogs suggest

[40/70 Benchmark]

1 minute ago, Stormchaserchuck1 said:

I don't think the SE, US will be below average temps like a lot of historical analogs suggest

Agree. I wonder if a neutralish PDO with an El Niño of this magnitude doesn't shift the STJ inward and upward relative to climo for intense El Niño.

[Stormchaserchuck1]

4 minutes ago, 40/70 Benchmark said:

Agree. I wonder if a neutralish PDO with an El Niño of this magnitude doesn't shift the STJ inward and upward relative to climo for intense El Niño.

I'm not actually taking for granted that the El Nino will actually do anything to the N. Pacific pattern. Models have -120 to 200dm on monthly means... they usually don't bust that bad... but we are in a "time" where the N. Pacific low is trending more and more out of the picture completely. Just the way it's going. 

[40/70 Benchmark]

7 minutes ago, 40/70 Benchmark said:

Agree. I wonder if a neutralish PDO with an El Niño of this magnitude doesn't shift the STJ inward and upward relative to climo for intense El Niño.

[40/70 Benchmark]

3 minutes ago, Stormchaserchuck1 said:

I'm not actually taking for granted that the El Nino will actually do anything to the N. Pacific pattern. Models have -120 to 200dm on monthly means... they usually don't bust that bad... but we are in a "time" where the N. Pacific low is trending more and more out of the picture completely. Just the way it's going. 

Sure, but the question you need to ask yourself..."is it already out of the picture completely"...because if the answer is no, then it will show up this season. 

[Stormchaserchuck1]

2 minutes ago, 40/70 Benchmark said:

Usually that storm track happens in +NAO
 

raindancewx still has to tell me how he gets U of Del precip working on that map lol

[40/70 Benchmark]

8 minutes ago, 40/70 Benchmark said:

BTW, if you have seen the EURO and CANSIPS snowfall output, this appears to be what these models do.

[Stormchaserchuck1]

2 minutes ago, 40/70 Benchmark said:

Sure, but the question you need to ask yourself..."is it already out of the picture completely"...because if the answer is no, then it will show up this season. 

So far it hasn't

I agree that the cold season will be super interesting to see if it happens or not. Like I said models showing -200dm for a monthly mean, are they that bad? lol

[40/70 Benchmark]

2 minutes ago, Stormchaserchuck1 said:

Usually that storm track happens in +NAO
 

raindancewx still has to tell me how he gets U of Del precip working on that map lol

Should be in the seasonal mean, but we need to time one during the negative intervals...there should be some.

[40/70 Benchmark]

3 minutes ago, Stormchaserchuck1 said:

So far it hasn't

I agree that the cold season will be super interesting to see if it happens or not. Like I said models showing -200dm for a monthly mean, are they that bad? lol

Well, like you said....we need to give it through October.

[40/70 Benchmark]

7 hours ago, Stormchaserchuck1 said:

Thanks! They don't have SST so I will still have to find something for May-Sept N. Atlantic SSTA index. 

Here's that arctic -H5 for the warm season this year

90N.. just where my reverse correlation for the Winter is the highest. Expect 90N H5 ridging for the DJFM mean. 

August isn't quite out yet...May-July:

https://psl.noaa.gov/data/atmoswrit/map/index.html

[40/70 Benchmark]

August should be out early next week.

[40/70 Benchmark]

7 minutes ago, 40/70 Benchmark said:

August isn't quite out yet...May-July:

https://psl.noaa.gov/data/atmoswrit/map/index.html

30 Day change:

[40/70 Benchmark]

You can see that NF cold pool go bye-bye, as I was expecting earlier this summer.

[Stormchaserchuck1]

4 minutes ago, 40/70 Benchmark said:

August should be out early next week.

Looks like 9/2 is ~+0.40... should come in ~-0.10 for MJJAS. That would actually be our 2nd lowest NAO Winter in 14 years (CPC). I'll take the over on that (CPC), although there could be some ridging around 80-90N.