2025-2026 ENSO

[GaWx]

9 minutes ago, bluewave said:

The SSTs along the West Coast were the warmest on record during the 2014-2015 +PDO event. Those raw indices values you posted were only a small piece of the total event. As those raw indices can often miss the totality of events. Like we often see between the 500mb versions of the teleconnections and the surface pressure versions. My analysis involves a bigger picture view rather than the more narrowly defined approach that you are taking. 
 

 

 1. But the SSTs along the W coast are just a portion of the entire PDO calculation. Just looking at the W coast like you did seems more narrow to me.

2. The SSTs in 2014-5 being at the warmest on record (per what you said) aren’t surprising due to global warming. And again, the full PDO calculation also involves other areas.

[bluewave]

25 minutes ago, GaWx said:

 1. But the SSTs along the W coast are just a portion of the entire PDO calculation. Just looking at the W coast like you did seems more narrow to me.

2. The SSTs in 2014-5 being at the warmest on record (per what you said) aren’t surprising due to global warming. And again, the full PDO calculation also involves other areas.

Notice how wide the band of +PDO SST warming was from Mexico all the way to Alaska with the +PDO super El Niño event in 15-16.  It far surpassed anything we have ever seen from a +PDO and El Niño combo before.

The reason the raw index you posted was underdone was due to the much smaller cold pool to the west of the +PDO horseshoe. So the footprint of the historic +PDO was larger leading to the normally cold regions to the west being smaller.

This why the SST charts below are a better indicator of the strength of the event. As the raw index was too narrowly defined to capture the sheer volume of historic SST warmth near the coast. So we need to update the way we calculate these indices in a rapidly warming world with more extreme marine heatwaves.

We have seen this same process at work with the raw telconnections struggling to capture the totality of events which have more often been defined by the record 500mb heights. 

 

 

[GaWx]

21 minutes ago, bluewave said:

Notice how wide the band of +PDO SST warming was from Mexico all the way to Alaska with the +PDO super El Niño event in 15-16.  It far surpassed anything we have ever seen from a +PDO and El Niño combo before.

The reason the raw index you posted was underdone was due to the much smaller cold pool to the west of the +PDO horseshoe. So the footprint of the historic +PDO was larger leading to the normally cold regions to the west being smaller.

This why the SST charts below are a better indicator of the strength of the event. As the raw index was too narrowly defined to capture the sheer volume of historic SST warmth near the coast. So we need to update the way we calculate these indices in a rapidly warming world with more extreme marine heatwaves.

We have seen this same process at work with the raw telconnections struggling to capture the totality of events which have more often been defined by the record 500mb heights. 

 

 

Chris,

 Nice maps. But these maps for 2015-6 also reflect on the globe being warmer in general vs 1997-8 and 1982-3. So, that alone favors for 2015-6 both a larger above normal area off the W coast and a smaller, less intense area of below normal further offshore. It is as I assume you’d agree the contrast between those two main areas that determines the intensity of the +PDO rather than just the intensity of warmth just offshore the W coast.

[40/70 Benchmark]

3 minutes ago, GaWx said:

Chris,

 Nice maps. But these maps for 2015-6 also reflect on the globe being warmer in general vs 1997-8 and 1982-3. So, that alone favors for 2015-6 both a larger above normal area off the W coast and a smaller, less intense area of below normal further offshore.

Yes, this is what I was getting at when I said that CC is in fact impacting the SST imprint for the modes of the PDO, but I stand by my assertion that the oscillstion/cycle/secular is no different.

[Typhoon Tip]

1 hour ago, 40/70 Benchmark said:

Yes, this is what I was getting at when I said that CC is in fact impacting the SST imprint for the modes of the PDO, but I stand by my assertion that the oscillstion/cycle/secular is no different.

[michsnowfreak]

Thanks to some good conversation with @Stormchaserchuck1 I dove further into the ENSO data for Detroit. And its actually surprising to see how relatively close the different ENSO states are, sensible weather wise. I suspect if many of you look at your local data, you may also be surprised. I think one of things is we all look into some of those "token" years and assume all ENSOs of that magnitude will yield similar results, but when you look at the mean...yes there are differences, but the differences are not as cut and dry as those cookie-cutter "what to expect this winter" graphics noaa puts out every fall before an expected El Nino or La Nina winter. 

Strong El Ninos here, as expected, are by far the warmest and least snowy...and weak La Ninas are the wettest/snowiest. But weak El Ninos are surprisingly the coldest and driest. Neutral are generally the preferred winters (and it doesnt show in this data, but 2nd and 3rd year neutral is usually REALLY the best). But all of that noise aside, all of the data is FAR closer than I was expecting.

 

ALL El Ninos (27 since 1950)
DJF temp avg: 27.9F
DJF precip avg: 6.07”
Season snow avg: 37.4”
1”+ snowcover avg: 44 days

ALL La Ninas (25 since 1950)
DJF temp avg: 27.8F
DJF precip avg: 6.77”
Season snow avg: 44.9”
1”+ snowcover avg: 49 days

ALL Neutral years (23 since 1950)
DJF temp avg: 26.6F
DJF precip avg: 6.66”
Season snow avg: 44.6” 
1”+ snowcover avg: 55 days

1950-2025 AVG (75 years)
DJF temp avg: 27.5F
DJF precip avg: 6.40”
Season snow avg: 41.5”
1”+ snowcover avg: 49 days
 

DIFFERENT EL NINO STRENGTHS

Strong El Ninos (9 since 1950)
DJF temp avg: 30.7F 
DJF precip avg: 6.44”
Season snow avg: 29.9”
1”+ snowcover avg: 31 days

 

Moderate El Ninos (7 since 1950)
DJF temp avg: 27.6F
DJF precip avg: 6.29”
Season snow avg: 42.3”
1”+ snowcover avg: 45 days

 

Weak El Ninos (11 since 1950)
DJF temp avg: 25.8F
DJF precip avg: 5.63”
Season snow avg: 40.4”
1”+ snowcover avg: 55 days
 

DIFFERENT LA NINA STRENGTHS

Strong La Ninas (7 since 1950)
DJF temp avg: 27.7F
DJF precip avg: 6.72”
Season snow avg: 49.2”
1”+ snowcover avg: 53 days
 

Moderate La Ninas (6 since 1950)
DJF temp avg: 28.0F
DJF precip avg: 5.46”
Season snow avg: 37.7” 
1”+ snowcover avg: 40 days
 

Weak La Ninas (12 since 1950)
DJF temp avg: 27.8F
DJF precip avg: 7.45”
Season snow avg: 46.0”
1”+ snowcover avg: 51 days

 

[40/70 Benchmark]

On 4/28/2025 at 6:11 PM, Stormchaserchuck1 said:

You weren't too cold last Winter. It is good to see what you are doing right and wrong though in seasonal outlooks.. at least you are doing seasonal outlooks. You are 1 of 2 people on here that does that.. it's one thing to talk about things after the fact, it's another thing to use methodology to try to predict it in advance. 

No, last season I was actually a bit too warm, but snowfall was pretty good. As much as I quibble with Chris, I have to credit him for the adjustments I made last season. Many of his posts on the changes we are seeing in the WPAC were very illuminating, and I was able to see why I have been busting cold and snowy the past couple of seasons in this regime. We often don't see eye to eye, but he definitely brings a lot to the table. I think he has the right idea generally speaking, but he is just a bit more aggressive with extrapolating larger scale changes forward than I am.

[40/70 Benchmark]

21 hours ago, Typhoon Tip said:

Tongue-in-cheek...I'm with you on that.

[40/70 Benchmark]

On 4/28/2025 at 6:16 PM, Stormchaserchuck1 said:

We are still in decadal -PDO, although that may change over the next 3-4 Winters with a higher likelihood of El Nino coming in 26-27 and 27-28, imo. I would even say the +2-3 year time frame is 2-3x more likely to see El Nino than La Nina.. if that happens over a few years, the PDO may not be so negative anymore... although the PDO is less connected to ENSO than you would think. 

I agree. My inference is that we are just beginning to shift and it should continue throughout the latter portion of this decade...but obviously recovery from the depth of this multidecadal nadir will take some time.

[40/70 Benchmark]

On 4/28/2025 at 7:52 PM, Stormchaserchuck1 said:

A big reason we didn't have big snows last Winter was the La Nina subtropical jet.. this started in May 2024, just when ENSO usually starts effecting for the year.. If I had to guess, I would say last Winter acted like a Moderate east-based La Nina. 

Yes, it did shift to a Modoki configuration, but it was late.

[bluewave]

22 hours ago, GaWx said:

Chris,

 Nice maps. But these maps for 2015-6 also reflect on the globe being warmer in general vs 1997-8 and 1982-3. So, that alone favors for 2015-6 both a larger above normal area off the W coast and a smaller, less intense area of below normal further offshore. It is as I assume you’d agree the contrast between those two main areas that determines the intensity of the +PDO rather than just the intensity of warmth just offshore the W coast.

Yeah, in a warmer world the troughs are becoming weaker. So the SSTs below haven’t been cooling as much. The cold pool couplet of the +PDO back in 2015 over the Central Pacific was much weaker than we saw back in 1997 due to the much weaker Aleutian Low. But the warm pool and 500 mb ridge near the West Coast was much stronger. So using the older calculation method doesn’t yield as strong of a +PDO. 

This raises the interesting question about future +PDOs in a warming world. Will there ever be an extended +PDO like we saw from the 1970s to 1990s again if we continue to see so much SST warmth from the CP back to the WP? Maybe this is why the +PDO cycle back in 2010s was so short.

The other observation is that this recent -PDO has been more defined by the warm pool over the Western to Central Pacific than the cold pool near the West Coast. This is due to the much stronger Aleutian Ridge and weaker -PNA 500 mb trough than we saw from the 1950s to 1970s during that -PDO era. So the calculation method actually helped the -PDO values in recent years rival or match the older values from the 1950s to 1970s. Even though the trough near the West Coast was weaker than past -PDOs and SSTs warmer. 

I think we are just going to have to take a wait and see approach to the lengths of these PDO phases going forward. As a much warmer Western Pacific from the Maritime Continent to the south of the Aleutians loads the dice for more -PDOs than +PDOs. We will have to see if there is some possibility of the Eastern Pacific seeing an accelerated warming while the Western Pacific cools in the coming years. But if the Western Pacific continues to stay warm and increase the warmth, then +PDOs may be harder to come by. 

A clue as to if this can happen could be the unusual warming last few years in the Nino 1+2 region and rapid rise in global temperatures. But we recently saw how that shallow warm pool could connect to the warm pool over the WP. So the stronger trades cooled it off and slowed a return to El Niño. But historically as least since 1950, we haven’t seen such a fast return to El Niño following such a strong El Niño like we had in 23-24. 
 

 

[40/70 Benchmark]

2 minutes ago, bluewave said:

Yeah, in a warmer world the troughs are becoming weaker. So the SSTs below haven’t been cooling as much. The cold pool couplet of the +PDO back in 2015 over the Central Pacific was much weaker than we saw back in 1997 due to the much weaker Aleutian Low. But the warm pool and 500 mb ridge near the West Coast was much stronger. So using the older calculation method doesn’t yield as strong of a +PDO. 

This raises the interesting question about future +PDOs in a warming world. Will there ever be an extended +PDO like we saw from the 1970s to 1990s again if we continue to see so much SST warmth from the CP back to the WP? Maybe this is why the +PDO cycle back in 2010s was so short.

The other observation is that this recent -PDO has been more defined by the warm pool over the Western to Central Pacific than the cold pool near the West Coast. This is due to the much stronger Aleutian Ridge and weaker -PNA 500 mb trough than we saw from the 1950s to 1970s during that -PDO era. So the calculation method actually helped the -PDO values in recent years rival or match the older values from the 1950s to 1970s. Even though the trough near the West Coast was weaker than past -PDOs and SSTs warmer. 

I think we are just going to have to take a wait and see approach to the lengths of these PDO phases going forward. As a much warmer Western Pacific from the Maritime Continent to the south of the Aleutians loads the dice for more -PDOs than +PDOs. We will have to see if there is some possibility of the Eastern Pacific seeing an accelerated warming while the Western Pacific cools in the coming years. But if the Western Pacific continues to stay warm and increase the warmth, then +PDOs may be harder to come by. 

A clue as to if this can happen could be the unusual warming last few years in the Nino 1+2 region and rapid rise in global temperatures. But we recently saw how that shallow warm pool could connect to the warm pool over the WP. So the stronger trades cooled it off and slowed a return to El Niño. But historically as least since 1950, we haven’t seen such a fast return to El Niño following such a strong El Niño like we had in 23-24. 
 

 

Yes., exactly. But I still don't see any difference between the warmer interlude circa 2025, during the multidecadal cold phase, and the late 1950s warmer period. They were both ENSO induced deviations from the predominate multidecadal cycle, which is why they were shorter in duration than warm phases that were congruent with the multidecadal state.

[bluewave]

5 minutes ago, 40/70 Benchmark said:

Yes., exactly. But I still don't see any difference between the warmer interlude circa 2025, during the multidecadal cold phase, and the late 1950s warmer period. They were both ENSO induced deviations from the predominate multidecadal cycle, which is why they were shorter in duration than warm phases that were congruent with the multidecadal state.

The big difference was that we didn’t have any effective +PDO and super El Niño anywhere near the magnitude of 2015-2016 from the late 1940s into 1970s. So while we may be seeing some weak echoes or reflections of the way the last cycles played out, I stand by my observation that the 2015-2016 event was a full blown +PDO cycle even though is was greatly reduced in duration. But the effective magnitude was stronger when we combine total EPAC warmth along the West Coast and the ENSO SSTs than 82-83 and 97-98 which were in the same defined  common +PDO era.

[40/70 Benchmark]

11 minutes ago, bluewave said:

The big difference was that we didn’t have any effective +PDO and super El Niño anywhere near the magnitude of 2015-2016 from the late 1940s into 1970s. So while we may be seeing some weak echoes or reflections of the way the last cycles played out, I stand by my observation that the 2015-2016 event was a full blown +PDO cycle even though is was greatly reduced in duration. But the effective magnitude was stronger when we combine total EPAC warmth along the West Coast and the ENSO SSTs than 82-83 and 97-98 which were in the same defined  common +PDO era.

Very large leap of faith on your part due to what can be easily explained by simply variance, which should be the baseline assumption. I think the ceiling for peak ONI during warm ENSO episodes is increasing, but I just disagree with your claim that the mulidecadal cycle has been altered.

[40/70 Benchmark]

1997 and 2015 each had a peak RONI value of 2.38. 1997 achieved a stronger peak MEI value of 2.6, as comparied to the 2015 peak value of 2.2. 2015 was stronger per ONI (2.6 vs 2.4), which kind of supports my premise regarding the higher ONI potential.

 

[bluewave]

13 minutes ago, 40/70 Benchmark said:

Very large leap of faith on your part due to what can be easily explained by simply variance, which should be the baseline assumption. I think the ceiling for peak ONI during warm ENSO episodes is increasing, but I just disagree with your claim that the mulidecadal cycle has been altered.

It’s not a leap of faith on my part since there were studies published about the +PDO shift around 2013 to 2015 and the jump in global temperatures. 
 

Initialized decadal prediction for transition to positive phase of the Interdecadal Pacific Oscillation

https://www.nature.com/articles/ncomms11718

The negative phase of the Interdecadal Pacific Oscillation (IPO), a dominant mode of multi-decadal variability of sea surface temperatures (SSTs) in the Pacific, contributed to the reduced rate of global surface temperature warming in the early 2000s. A proposed mechanism for IPO multidecadal variability indicates that the presence of decadal timescale upper ocean heat content in the off-equatorial western tropical Pacific can provide conditions for an interannual El Niño/Southern Oscillation event to trigger a transition of tropical Pacific SSTs to the opposite IPO phase. Here we show that a decadal prediction initialized in 2013 simulates predicted Niño3.4 SSTs that have qualitatively tracked the observations through 2015. The year three to seven average prediction (2015–2019) from the 2013 initial state shows a transition to the positive phase of the IPO from the previous negative phase and a resumption of larger rates of global warming over the 2013–2022 period consistent with a positive IPO phase.

 

[40/70 Benchmark]

9 minutes ago, bluewave said:

It’s not a leap of faith on my part since there were studies published about the +PDO shift around 2013 to 2015 and the jump in global temperatures. 
 

Initialized decadal prediction for transition to positive phase of the Interdecadal Pacific Oscillation

https://www.nature.com/articles/ncomms11718

The negative phase of the Interdecadal Pacific Oscillation (IPO), a dominant mode of multi-decadal variability of sea surface temperatures (SSTs) in the Pacific, contributed to the reduced rate of global surface temperature warming in the early 2000s. A proposed mechanism for IPO multidecadal variability indicates that the presence of decadal timescale upper ocean heat content in the off-equatorial western tropical Pacific can provide conditions for an interannual El Niño/Southern Oscillation event to trigger a transition of tropical Pacific SSTs to the opposite IPO phase. Here we show that a decadal prediction initialized in 2013 simulates predicted Niño3.4 SSTs that have qualitatively tracked the observations through 2015. The year three to seven average prediction (2015–2019) from the 2013 initial state shows a transition to the positive phase of the IPO from the previous negative phase and a resumption of larger rates of global warming over the 2013–2022 period consistent with a positive IPO phase.

 

Okay, large leap of faith on your part, as well as the authors of said studies.

[40/70 Benchmark]

AFAIC, the PDO continues to cycle as it always has.....if we are still immersed in a -PDO cycle well into the next decade, then I'll reconsider.

I am not trying to imply that you make baseless claims, so your presentation of peer reviewed literature doesn't suprise me. You and the identified authors may end up 1000% correct...I'm just not as condident that they will as you are.

[bluewave]

13 minutes ago, 40/70 Benchmark said:

Okay, large leap of faith on your part, as well as the authors of said studies.

The PDO actually shifted during those years which is an undeniable fact. So there hasn’t been a continuous -PDO from 1998 to 2025 like we had from the 1950s to 1970s. So the character and duration of the PDO intervals is different from the mid to late 1900s.

[40/70 Benchmark]

5 minutes ago, bluewave said:

The PDO actually shifted during those years which is an undeniable fact. So there hasn’t been a continuous -PDO from 1998 to 2025 like we had from the 1950s to 1970s. So the character and duration of the PDO intervals is different from the mid to late 1900s.

No, it isn't a fact...I, along with everyone else in this thread, is denying it. The graph I posed clearly shows no discernible difference, and continues to have ENSO triggered deviations from the longer term, multidecadal tendency.

[bluewave]

1 minute ago, 40/70 Benchmark said:

No, it isn't a fact...I, along with everyone else in this thread, is denying it. The graph I posed clearly shows no discernible difference, and continues to have ENSO triggered deviations from the longer term, multidecadal tendency.

The graph you posted doesn’t take into account the SST changes I mentioned in my earlier posts which affect the calculations. Plus the study I posted about the recent shift. Model forecasts show the duration of the PDO phases becoming more erratic as the climate continues to warm.

 

[FPizz]

45 minutes ago, 40/70 Benchmark said:

Okay, large leap of faith on your part, as well as the authors of said studies.

It is pretty easy to find studies that agree with you and ones the go against others ideas.  Pick your poison kind of deal.  You can go all in either way, but I feel like that clouds judgements as we have seen posted here and elsewhere.

[40/70 Benchmark]

26 minutes ago, bluewave said:

The graph you posted doesn’t take into account the SST changes I mentioned in my earlier posts which affect the calculations. Plus the study I posted about the recent shift. Model forecasts show the duration of the PDO phases becoming more erratic as the climate continues to warm.

 

Well, looks the same to me so far and I will treat it as such. You do you. I am totally open to being stuck in a longer term PDO state because we can't be sure of how CC is going to impact everything moving forward, and if that is the case, then I will interpret things differently.

10 minutes ago, FPizz said:

It is pretty easy to find studies that agree with you and ones the go against others ideas.  Pick your poison kind of deal.

Yup. And both sides are going present the studies that support their own beliefs. I think the most objective position possible is to admit that we just don't know for certain and to maintain an open mind. 

[40/70 Benchmark]

If Chris is correct, then we should start seeing more supplentary indexes coming out to bridge the gap between the past data and the more modern climate, like we have with respect to ENSO. 

Just to be clear, I am not necessarily saying that he is wrong...perhaps the warmer climate has rendered the PDO calculation as we knew it to be obsolete, but all I am saying is that I need to see how the next 7-10 years turn out to be certain that that is the case. If that is indeed true, then I will adjust how I view the PDO and incoporprate it into my forecasts, just as I with did ENSO this past season.

[brooklynwx99]

I don't think there's any legitimate way that the 2013-15 +PDO could be viewed as a "three year cycle" or whatever. there have been numerous instances of +PDO in -PDO cycles and vice versa since the 40s. it's nothing new. you can see the same thing in the late 50s, late 80s, and the mid-2000s. IMO it's just authors trying to rationalize typical variance as a broader consequence of climate change