2025 ENSO Updates

[cycloneye]

Only a few hours are left for 2024 to end, but the last weekly CPC update is out and is an anticipation of what is coming in the first few months of 2025. After this niño 3.4 -1.1C reading, for sure they will declare officially La Niña. The big question is how long it will last,if it gets to moderate and when it goes away, how neutral it may be, if cold, or warm. And of course, the members can make comments about what is going on with ENSO.

This thread will have all the information so stay tuned here.

Hyperlink to PDO data

Hyperlink to ONI since 1950

Hyperlink to 2024 ENSO Updates thread

Hyperlink to ENSO Update threads from 2007 thru 2023



https://www.longpaddock.qld.gov.au/soi/











https://www.cpc.ncep.noaa.gov/products/ ... ts-web.pdf

[Kingarabian]

A weak warm subsurface pool will likely form by late Jan and will eventually make it's way to the EPAC by March.

[cycloneye]

A weak warm subsurface pool will likely form by late Jan and will eventually make it's way to the EPAC by March.

My question is why do you know that warm pool will form by that month?

[Kingarabian]

A weak warm subsurface pool will likely form by late Jan and will eventually make it's way to the EPAC by March.

My question is why do you know that warm pool will form by that month?

Recent Climo since 2014 supports this happening. MJO is at its strongest over the Pacific during this timeframe.

[Yellow Evan]

The North Pacific looks the most cooperative towards + ENSO in a while but a strong +PDO/PMM configuration has not emerged to the point where it’s outright favorable for +ENSO. MJO has been mostly lingering in the IO so far this winter, which does not bond well for the change in trade pattern and respective surface and sub-surface changes needed to reverse the current -ENSO state. It’s only January so both of these factors can change but -ENSO is favored right now.

[cycloneye]

There are diverse takes about where will ENSO be by next summer.

 https://x.com/PaulRoundy1/status/1875880018686996974

[cycloneye]

CPC weekly update has niño 3.4 warming a little bit up to -0.7C from -1.1C that was in last weeks update. Next thursday CPC will probably declare officially La NIña.



https://www.cpc.ncep.noaa.gov/products/ ... ts-web.pdf

[Kingarabian]

Waters in the Nino regions could warm up by spring due to a warm pool likely forming but they will only cool back down by the summer. But weak El Nino or sustained +ENSO is highly unlikely. You would need WWBs for that to occur and we didn't see any the past 3 months nor are there any in the forecast for January. Usually if there is going to be an attempt at El Nino the dateline trades would be attempting to slow down. Might see a WWB in mid to late February and something in March, but that's about it. Per climo, It's also unlikely to get another El Nino event this soon after a strong El Nino.

La Nina/Cool Neutral is the best call for this summer.

[cycloneye]

Waters in the Nino regions could warm up by spring due to a warm pool likely forming but they will only cool back down by the summer. But weak El Nino or sustained +ENSO is highly unlikely. You would need WWBs for that to occur and we didn't see any the past 3 months nor are there any in the forecast for January. Usually if there is going to be an attempt at El Nino the dateline trades would be attempting to slow down. Might see a WWB in mid to late February and something in March, but that's about it. Per climo, It's also unlikely to get another El Nino event this soon after a strong El Nino.

La Nina/Cool Neutral is the best call for this summer.

Something interesting going on is that the 30 day SOI has tumbled in the past few weeks and that goes to what you are saying about warming by spring.



https://www.longpaddock.qld.gov.au/soi/

[cycloneye]

 https://x.com/TylerJStanfield/status/1877037408522248469

[cycloneye]

La Niña conditions are present and are expected to persist through February-April 2025 (59% chance), with a transition to ENSO-neutral likely during March-May 2025 (60% chance).

 https://x.com/NWSCPC/status/1877354647024803996

[cycloneye]

Here is the ENSO Blog from CPC.

https://www.climate.gov/news-features/b ... -nina-here

Extract:

With the Niño-3.4 Index exceeding the La Niña threshold of -0.5 °C, we can move on to the second box on our flowchart—do we think the Niño-3.4 index is going to stay in La Niña territory for the next several seasons? (“Seasons” here means any 3-month-average period.) The consensus among our computer climate models is yes. Also, there is a substantial amount of cooler-than-average water under the surface of the tropical Pacific, which will provide a source for the surface over the next few months.

So, we’re on to the third box, which has actually been checked for a while now (more on that later). The atmosphere has been looking La Niña-ish for months, with stronger-than-average trade winds, more clouds and rain over Indonesia, and drier conditions over the central Pacific—all hallmarks of an amped-up Walker circulation. In December, the Equatorial Southern Oscillation Index (EQSOI), which measures the difference in surface pressure between the western and eastern Pacific, was 1.5 (positive values indicate a stronger Walker circulation). In fact, this is the 5th-strongest December EQSOI in the historical record. Drumroll… La Niña conditions have developed.

[cycloneye]

 https://x.com/philklotzbach/status/1877371966828453946

[cycloneye]

 https://x.com/RyanMaue/status/1877763295425290576

[Ntxw]

-21 Daily SOI, not your typical way to run deep into nhem winter for a Nina. It's been strange that the mid to high latitude patterns have not been in sync. 2023-2024 El Nino we had -PDO Aleutian ridge interfere. Now we have a Aleutian trough do the same thing for the Nina.

[cycloneye]

-21 Daily SOI, not your typical way to run deep into nhem winter for a Nina. It's been strange that the mid to high latitude patterns have not been in sync. 2023-2024 El Nino we had -PDO Aleutian ridge interfere. Now we have a Aleutian trough do the same thing for the Nina.

It means the weak La Niña will not last too long right?

[Yellow Evan]

-21 Daily SOI, not your typical way to run deep into nhem winter for a Nina. It's been strange that the mid to high latitude patterns have not been in sync. 2023-2024 El Nino we had -PDO Aleutian ridge interfere. Now we have a Aleutian trough do the same thing for the Nina.

The WPAC warmth and (until recently) the east based focused of the Nina is changing the calculus a bit, favoring -WPO and +TNH. Not unlike 2013-14 winter in that regard.

[Ntxw]

-21 Daily SOI, not your typical way to run deep into nhem winter for a Nina. It's been strange that the mid to high latitude patterns have not been in sync. 2023-2024 El Nino we had -PDO Aleutian ridge interfere. Now we have a Aleutian trough do the same thing for the Nina.

It means the weak La Niña will not last too long right?

It's very weak, and there's still a possibility it won't make the 5 month criteria. We may get one later this year though but too early to tell.

[cycloneye]

This looks interesting. Look at the warm anomalies creeping beneath the cold ones.

[cycloneye]

CPC weekly update has niño 3.4 the same as last week's one at -0.7C.

https://www.cpc.ncep.noaa.gov/products/ ... ts-web.pdf