2025-2026 ENSO

[bluewave]

17 hours ago, GaWx said:

Despite Chris’ good thoughts and sources, I’m with you and @40/70 Benchmarkand still say 2014-6 was nearly a carbon copy of the late 1950s, a couple of year long +PDO period during a couple year long El Niño with a strong to very strong El Niño peak in the middle of a -PDO regime. This graph you posted says it all.

 The late 1980s was fairly similar but the opposite situation.

 

 

While shorter PDO cycles in a warming climate may be a new concept to some on this forum, this has been a topic of interest in the climate community for a while now. It’s acknowledged that the decadal cycle broke down in 1998. This is why the PDO has been seeing such quick shifts from one phase to another since then. 

https://journals.ametsoc.org/view/journals/clim/29/16/jcli-d-15-0690.1.xml#:~:text=Abstract The impact of climate change on,in response to global warming or cooling.

In the control simulations the model PDO has an approximately bidecadal peak. In a warmer climate the PDO time scale becomes shorter, changing from ~20 to ~12 yr. In a colder climate the time scale of the PDO increases to ~34 yr. Physically, global warming (cooling) enhances (weakens) ocean stratification. The increased (decreased) ocean stratification acts to increase (reduce) the phase speed of internal Rossby waves, thereby altering the time scale of the simulated PDO.

https://www.fisheries.noaa.gov/west-coast/science-data/climate-and-atmospheric-indicators

These decadal cycles broke down in late 1998 when the PDO entered a cold phase that lasted only five years. This cold phase was followed by a warm phase from 2003 to 2007 and an abrupt change to a cold phase from 2008 to 2013 (with a short interruption during the moderate El Niño in fall/winter 2009-2010). The PDO then switched phases again in 2014 and remained positive until 2018. This period coincided with a large marine heatwave and El Niño that negatively impacted the marine ecosystem in the NE Pacific during that time. Since 2020, the PDO has been consistently negative, reaching the most negative values since 1955 in both 2022 and 2023.

[GaWx]

1 hour ago, bluewave said:

 

While shorter PDO cycles in a warming climate may be a new concept to some on this forum, this has been a topic of interest in the climate community for a while now. It’s acknowledged that the decadal cycle broke down in 1998. This is why the PDO has been seeing such quick shifts from one phase to another since then. 

https://journals.ametsoc.org/view/journals/clim/29/16/jcli-d-15-0690.1.xml#:~:text=Abstract The impact of climate change on,in response to global warming or cooling.

In the control simulations the model PDO has an approximately bidecadal peak. In a warmer climate the PDO time scale becomes shorter, changing from ~20 to ~12 yr. In a colder climate the time scale of the PDO increases to ~34 yr. Physically, global warming (cooling) enhances (weakens) ocean stratification. The increased (decreased) ocean stratification acts to increase (reduce) the phase speed of internal Rossby waves, thereby altering the time scale of the simulated PDO.

https://www.fisheries.noaa.gov/west-coast/science-data/climate-and-atmospheric-indicators

These decadal cycles broke down in late 1998 when the PDO entered a cold phase that lasted only five years. This cold phase was followed by a warm phase from 2003 to 2007 and an abrupt change to a cold phase from 2008 to 2013 (with a short interruption during the moderate El Niño in fall/winter 2009-2010). The PDO then switched phases again in 2014 and remained positive until 2018. This period coincided with a large marine heatwave and El Niño that negatively impacted the marine ecosystem in the NE Pacific during that time. Since 2020, the PDO has been consistently negative, reaching the most negative values since 1955 in both 2022 and 2023.

Thanks Chris,

 Keep in mind that that analysis is likely based on the Mantua et al PDO, which is more positive than NOAA’s, and is definitely based on only May-Sept for whatever reason (see image below). But if they had done it based on NOAA, it would have been more negative. In addition, why not look at the entire year?

 

[40/70 Benchmark]

On 4/30/2025 at 1:10 PM, brooklynwx99 said:

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

AKA agenda.

[40/70 Benchmark]

The PDO assumed a more negative tendency right on cue with the periodicty with which it has always switched phases. There have always been ENSO induced deviations from the longer term tendency. I don't know....either everyone else on this forum is a moron, Chris is just a giant brain in a glass jar like Krang on Ninja Turtles bag in the day.

Shredddoooorrrr...the Hadley Cell is sinkinngggg!!!"

[40/70 Benchmark]

On 4/30/2025 at 1:27 PM, Maestrobjwa said:

Speaking of which...where is the PDO right now?

https://www.ncei.noaa.gov/access/monitoring/pdo/

-1.12 as of March..highest its been since August 2021.

[40/70 Benchmark]

21 hours ago, Stormchaserchuck1 said:

The problem with decadal cycles is that they are in such a short timeframe that you can say "Whatever X is, has to do with Y", and there's not enough data to disprove this.. I bet if the PDO was running 25 years positive, that would definitely be linked to climate change, no doubt. And that one you can probably make a stronger case for too. 

I don't think things like the NAO/AO/PDO are obsolete in this "new climate". For everytime the -NAO has linked up with a SE ridge, there are 3-4x more examples of warmer days happening when the NAO is positive.. Jan 26, 2024 it hit 80* in DC with the strongest +NAO for that timeframe, maybe on record (-300dm for a 5-day surrounding period). These fluctuations are still strong and constant in an overall warmer climate. I'm not going to make everything happening about a 2c global skew. 

Anyway, just an example:
In the older climate: -NAO -0.5 correlation with temperature

+NAO +0.5 correlation with temperature

New climate:

-NAO -0.2 correlation with temperature

+NAO +0.8 correlation with temperature

It's the same thing! 1.0 = 1.0.  NAO remains just as impactful. 

I am with you, but just trying to keep an open mind. He did makes some valid points regarding ENSO in a warming climate that while I was initially skeptical of, I ended up capitulating to. He is a very night guy, but no one bats .1000.

[40/70 Benchmark]

Almost done with my recap of last season and how I did...will post it in the other thread when I finish within the next week or so. 

Not perfect by any stretch, but much better than last year.

[Stormchaserchuck1]

Why does the PDO fluctuate more in a new climate though? Just because it happened once, and everything is getting warmer every day? It seems like you are looking at the '13-15 PDO period as strong in between strong -PDO periods, and saying "well since that happened it must be because of global warming". I don't think so. 

Global warming should be associated with a slowing of the pattern, leading to more stagnation, or persistent areas of high pressure. I think the windy/low pressure pattern that the Northern Hemisphere has been in since the Winter is anti-global warming (But that doesn't mean it's not going to keep warming). 

[csnavywx]

Isn't there a pretty well documented increase in C/EPac trade winds over the last 40+y? I'd think that (plus the aerosol pattern effect) would have a pretty drastic effect on SST patterns and the downstream Pac climate indices.

Also probably can't get away from the insane post-2020 NPac/NAtl warming (N Hem in general) and the effect it's already having on the position of the ITCZ/monsoon trough via response to differential warming.