2024 ENSO Updates

[cycloneye]

CPC at the September ENSO update has 71% of having la niña anytime in the September thru November period and it would last thru March 2025.

 https://x.com/NWSCPC/status/1834215387610665250

[cycloneye]

Here comes La Niña.

 https://x.com/BenNollWeather/status/1834935337774465252

[Kingarabian]

I guess when you subtract from the mean there's is a general trend of cooling. But it's still very slow. MJO is in the Pacific now so the 2nd half of September will slow things down again in terms of La Nina. Maybe by mid October and into November we can see sustained -0.5C anomalies.

[cycloneye]

CPC has niño 3.4 at -0.2C and La Niña is expected by October or November.



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

[Kingarabian]

Nino 3.4 at -0.5C this week.

[Kingarabian]

Nino 3.4 up to -0.2C this week. As cool neutral as it gets.

[cycloneye]

Looks like the upcomming La Niña will be a weak one that may last until March.

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

[Teban54]

Looks like the upcomming La Niña will be a weak one that may last until March.

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

https://i.imgur.com/t2TPVTz.gif

Unfortunately, it looks like the pre-season talks of how weak La Nina or cool neutral seasons are more dangerous for CONUS verified.

[Kingarabian]

-0.5C this week.

[xtyphooncyclonex]

Pretty big WWB coming up
 https://twitter.com/webberweather/status/1846679062284325298

[Kingarabian]

This weeks numbers:

Niño 4 0.1ºC
Niño 3.4 -0.3ºC
Niño 3 -0.1ºC
Niño 1+2 -0.1ºC

[xtyphooncyclonex]

 https://x.com/SDBrownWX/status/1848757802761916858

[Kingarabian]

If we don't get sustained La Nina anomalies at 3.4 during November then there will be no La Nina for 2024.

But this likely means a more efficient weak-moderate La Nina for 2025.

[xtyphooncyclonex]

If we don't get sustained La Nina anomalies at 3.4 during November then there will be no La Nina for 2024.

But this likely means a more efficient weak-moderate La Nina for 2025.

Models are also showing the possibility of no La Niña at all for 2025, especially given the increasingly warm Pacific (shift to +PMM) and WWBs. This could either be another 2017, 2020, or 2018.

[Kingarabian]

If we don't get sustained La Nina anomalies at 3.4 during November then there will be no La Nina for 2024.

But this likely means a more efficient weak-moderate La Nina for 2025.

Models are also showing the possibility of no La Niña at all for 2025, especially given the increasingly warm Pacific (shift to +PMM) and WWBs. This could either be another 2017, 2020, or 2018.

Well the models also thought we would be in a moderate to strong Nina by now.

I see a 2016-2017 scenario since 2024 played out the way it's currently playing out and we had a big El Nino in 2023.

[dexterlabio]

It would be easy to expect that this year would feature a strong La Niña given the -PDO and the cooling momentum going from El Niño to La Niña. It's puzzling how it's been a challenge to transition to La Niña.

[xtyphooncyclonex]

If we don't get sustained La Nina anomalies at 3.4 during November then there will be no La Nina for 2024.

But this likely means a more efficient weak-moderate La Nina for 2025.

Models are also showing the possibility of no La Niña at all for 2025, especially given the increasingly warm Pacific (shift to +PMM) and WWBs. This could either be another 2017, 2020, or 2018.

Well the models also thought we would be in a moderate to strong Nina by now.

I see a 2016-2017 scenario since 2024 played out the way it's currently playing out and we had a big El Nino in 2023.

We're arguably in a "relative" La Niña (or a La Niña based on the RONI (difference from global mean anomaly) as demonstrated below. This could explain how Pacific weather patterns and typhoon/hurricane activity has more closely resembled stronger La Niña seasons. Last year, we were in a "relative" moderate or weak-moderate El Niño. Could speculate a warmer relative ENSO could be seen more easily as a result than coming out of a year like 2015.

 https://twitter.com/BenNollWeather/status/1848668547561693419




However, the WWBs, MJOs and warming might make a "pure" La Niña quite a struggle to form in the next few months at least. Should the warm bias persist among the models, we could yet see another neutral-warm year in the books. Or at least a more active Pacific activity wise, as shown by the +PMM.

Nonetheless, I also do agree that we can't rule out a full-fledged La Niña either given the -PDO state, and the rarity of successive El Niños. The combination of these factors just makes 2025 more unpredictable than usual.

[Dean_175]

If we don't get sustained La Nina anomalies at 3.4 during November then there will be no La Nina for 2024.

But this likely means a more efficient weak-moderate La Nina for 2025.

Models are also showing the possibility of no La Niña at all for 2025, especially given the increasingly warm Pacific (shift to +PMM) and WWBs. This could either be another 2017, 2020, or 2018.

Models also showed an El Nino in 2017... and while the Pacific did begin to heat up in spring and early summer, it fell into La Nina by peak hurricane season. Some models hinted a possible "super La Nina" being present by now earlier in the year. Case in point: take everything with a grain of salt until after the spring predictability barrier passes.

[Kingarabian]

Niño 4 -0.1ºC
Niño 3.4 -0.5ºC
Niño 3 -0.2ºC
Niño 1+2 -0.2ºC

Numbers for this week

[Kingarabian]

GFS has a strong EPAC WWB. Pretty odd.