2024 ENSO Updates

[Dean_175]

GFS has another trade burst starting soon. It is possibly the final opportunity for a transition to La Nina in 2024.

[xtyphooncyclonex]

From what was expected to be a formidable La Niña...

A little surprising the mod-to-strong La Niña expected to develop in the middle of a -PMM/-PDO era did not happen.

 https://x.com/webberweather/status/1855999498608324921

[cycloneye]

La Niña in a weak status is likely to develop in the coming 2 months and last by January thru March 2025.

https://www.cpc.ncep.noaa.gov/products/ ... disc.shtml

 https://x.com/NWSCPC/status/1857060937993203863

[xtyphooncyclonex]

As evidenced by the flurry of late-season WPac super typhoons, the WWB seems to have put quite a dent on stronger Niña prospects.

 https://x.com/webberweather/status/1857482384217657427

[Kingarabian]

La Nina 2024 chances were in poor shape 3 months ago. Now that possibility is becoming a reality. But we should see an actual La Nina sometime in 2025.

[Kingarabian]

Nino 3.4 went up to 0.0C in this week's update.

[cycloneye]

Maybe La Niña may not show up after all?

 https://x.com/WorldClimateSvc/status/1857096219522175164

[Kingarabian]

Cool subsurface anomalies have been very weak all year long.

[xtyphooncyclonex]

 https://x.com/dmorris9661/status/1858953217289134251

[Category5Kaiju]

 https://x.com/dmorris9661/status/1858953217289134251

Would be interesting to see if those neutral conditions hold for the 2025 hurricane season; if they do, all else being equal, then that could indicate a pretty busy season again for the Atlantic. As we saw with 2005, 2017, and this year, typically when the Atlantic season occurs during neutral (especially cool neutral) conditions as opposed to solid Nino/Nina, we can get some pretty bad storms

[Kingarabian]

90 and 30 day SOIs are well below the +8 mark. So I wouldn't say La Nina is present in the atmosphere.

[WalterWhite]

 https://x.com/dmorris9661/status/1858953217289134251

Would be interesting to see if those neutral conditions hold for the 2025 hurricane season; if they do, all else being equal, then that could indicate a pretty busy season again for the Atlantic. As we saw with 2005, 2017, and this year, typically when the Atlantic season occurs during neutral (especially cool neutral) conditions as opposed to solid Nino/Nina, we can get some pretty bad storms

If we have a bone fide La Niña for 2025, 2020 also showed us that La Niña years that follow ENSO neutral years can be quite nasty. (Consider Laura, Sally, Delta, Zeta, Eta, and Iota)

[Ntxw]

Bump. Back in the Spring I mentioned how the ocean-atmosphere were not working completely in tandem and that the global warmth (particular extra-tropics) was masking an underlying problem for ENSO. All of the recent ENSO events the past few years have been interfered with at varying levels.

Should be interesting to see how strong this Niña will get. Majority of the guidance is suggesting we'll fall to at least the higher (or technically lower?) end of moderate territory, and a few (CFS, CanSIPS, UKMET) are saying we may legitimately reach the strong threshold by autumn (-1.5C and below). For reference, the triple dip we recently saw from 2020-23 peaked at -1.3C in OND 2020 per ONI. Given how surprisingly expeditious the process has been up to this point, I honestly wouldn't disregard such a scenario.

One cause for pause is since 2020 the oceanic SSTA hasn't been matching some of these model depictions. 2021 and 2022 were showing some potent Ninas but was weak-mod. I think the overall global warmth is toying with anomaly values. Those seasons the atmosphere was more potent Nina responses than the actual SSTA. Might happen again. Once we get the new 30 year base, going back the Ninas may get a boost in ONI than operationally once the the base climo is increased.

This occured just this past year when the warm mid and high latitude SSTA interfered with Nino.

In short, we just don't understand very well how this shift in SST warming in the higher latitudes, and tropical ocean for that matter, effects what we consider 'anomalies' relative to the norm.

[WalterWhite]

Bump. Back in the Spring I mentioned how the ocean-atmosphere were not working completely in tandem and that the global warmth (particular extra-tropics) was masking an underlying problem for ENSO. All of the recent ENSO events the past few years have been interfered with at varying levels.

Should be interesting to see how strong this Niña will get. Majority of the guidance is suggesting we'll fall to at least the higher (or technically lower?) end of moderate territory, and a few (CFS, CanSIPS, UKMET) are saying we may legitimately reach the strong threshold by autumn (-1.5C and below). For reference, the triple dip we recently saw from 2020-23 peaked at -1.3C in OND 2020 per ONI. Given how surprisingly expeditious the process has been up to this point, I honestly wouldn't disregard such a scenario.

One cause for pause is since 2020 the oceanic SSTA hasn't been matching some of these model depictions. 2021 and 2022 were showing some potent Ninas but was weak-mod. I think the overall global warmth is toying with anomaly values. Those seasons the atmosphere was more potent Nina responses than the actual SSTA. Might happen again. Once we get the new 30 year base, going back the Ninas may get a boost in ONI than operationally once the the base climo is increased.

This occured just this past year when the warm mid and high latitude SSTA interfered with Nino.

In short, we just don't understand very well how this shift in SST warming in the higher latitudes, and tropical ocean for that matter, effects what we consider 'anomalies' relative to the norm.

Could we always just subtract the global SST anomaly from the Nino 3.4 SST anomaly to get an index that is more immune to changes in climate?

[Ntxw]

Bump. Back in the Spring I mentioned how the ocean-atmosphere were not working completely in tandem and that the global warmth (particular extra-tropics) was masking an underlying problem for ENSO. All of the recent ENSO events the past few years have been interfered with at varying levels.

One cause for pause is since 2020 the oceanic SSTA hasn't been matching some of these model depictions. 2021 and 2022 were showing some potent Ninas but was weak-mod. I think the overall global warmth is toying with anomaly values. Those seasons the atmosphere was more potent Nina responses than the actual SSTA. Might happen again. Once we get the new 30 year base, going back the Ninas may get a boost in ONI than operationally once the the base climo is increased.

This occured just this past year when the warm mid and high latitude SSTA interfered with Nino.

In short, we just don't understand very well how this shift in SST warming in the higher latitudes, and tropical ocean for that matter, effects what we consider 'anomalies' relative to the norm.

Could we always just subtract the global SST anomaly from the Nino 3.4 SST anomaly to get an index that is more immune to changes in climate?

RONI has been brought up here several times. While it does help, we can't simply ignore the warming SSTs as if it's on its own island. It changes how ENSO influences the global pattern.

[Kingarabian]

RONI didn't matter much this year since the atmosphere did not shift into La Nina. Atmosphere resembled more of a cool neutral state which the regular ONI easily reflected.

[cycloneye]

A good thread at X about -ENSO going into 2025.

 https://x.com/WxPatel/status/1864123050016313519




 https://x.com/WxPatel/status/1864123052843221302




 https://x.com/WxPatel/status/1864123056408391730

[Kingarabian]

It's too late for a 2024 La Nina. 2025 is a different story though.

[cycloneye]

 https://x.com/BigJoeBastardi/status/1865054919876878584

[cycloneye]

CPC weekly update has niño 3.4 at -0.2C.

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