2026 ENSO Updates

[DorkyMcDorkface]

If the expected MJO in march doesn't cooperate, then the strong el niño status may not be in the cards? I guess time will tell.

Probably opens the door for a 2014 type situation where a stronger El Niño is potentially delayed onto the next year but there’s still weaker event also accompanied by a +PMM.

I guess a fail mode like that is still on the table but the subsurface warmth is just so expansive at the moment, it really won't take much of a WWB to get things going.

[cycloneye]

 https://x.com/BenNollWeather/status/2024144377422233627

[Dean_175]

If the expected MJO in march doesn't cooperate, then the strong el niño status may not be in the cards? I guess time will tell.

Well, in February, it is essentially always too soon to declare that a strong El Nino is most likely going to develop. In fact, there has never been a year where the NWS announced during the first quarter that a strong El Nino was likely. The ocean is favorable for development of El Nino and it is at the right time in the ENSO cycle for that to occur, but the amplitude is highly dependent on the MJO in spring-early summer. Right now, there is no +ENSO signal already in place, so the Bjerknes ocean/atmospheric feedback mechanism has not even begun. More about the amplitude will be known when the warm SSTAs actually materialize and you see how the atmosphere is responding. It is hard to predict El Nino's development through spring due to the lack of a mature/fully coupled signal and lots of noise (significant MJO variability brought about in part by seasonal maximum in mean total SST). Speculating on the amplitude now is like already calling a baseball game after watching only the first few pitches and saying "the last time our home team played this well, we won significantly!".

[Yellow Evan]

If the expected MJO in march doesn't cooperate, then the strong el niño status may not be in the cards? I guess time will tell.

Probably opens the door for a 2014 type situation where a stronger El Niño is potentially delayed onto the next year but there’s still weaker event also accompanied by a +PMM.

I guess a fail mode like that is still on the table but the subsurface warmth is just so expansive at the moment, it really won't take much of a WWB to get things going.
https://i.ibb.co/k2sPqCLX/armor-subsfc-anom-enso.png

It felt that way in real time in 2014 through April too only for trades to never really establish itself past the dateline until that fall and that winter much like this had a very different NPAC pattern than the years prior, translating to -NPO and +PMM. This year has more South Pacific support than 2014 so far, however. If we get a strong MJO passage over the Pacific next month and extended range guidance shows an El Niño standing wave, it makes a lot less sense as an analog.

[Yellow Evan]

If the expected MJO in march doesn't cooperate, then the strong el niño status may not be in the cards? I guess time will tell.

Well, in February, it is essentially always too soon to declare that a strong El Nino is most likely going to develop. In fact, there has never been a year where the NWS announced during the first quarter that a strong El Nino was likely. The ocean is favorable for development of El Nino and it is at the right time in the ENSO cycle for that to occur, but the amplitude is highly dependent on the MJO in spring-early summer. Right now, there is no +ENSO signal already in place, so the Bjerknes ocean/atmospheric feedback mechanism has not even begun. More about the amplitude will be known when the warm SSTAs actually materialize and you see how the atmosphere is responding. It is hard to predict El Nino's development through spring due to the lack of a mature/fully coupled signal and lots of noise (significant MJO variability brought about in part by seasonal maximum in mean total SST). Speculating on the amplitude now is like already calling a baseball game after watching only the first few pitches and saying "the last time our home team played this well, we won significantly!".

Eh we’re late enough in the game that I think we have a good idea - we’re near the time of year where Bjerknes feedbacks are the weakest because the the zonal temperature gradient is the smallest. Most years that were coming off a -ENSO like this one that featured with similar trade patterns (1982, 1997, 2002, and 2014 all featured WWB activity near 150E in DJF like this year) similar sub-surface (1997, 2002, 2009, 2014 are all roughly the same magnitude to right now), and similar Pacific sea surface temperature configurations including a defined +PMM and low amplitude PDO (1957, 1963, 1968, 1982, 2006 and 2014). Most of the aforementioned years evolved into moderate or stronger events so it’s reasonable to believe 2026 is more likely than not to behave the same way. As for the CPC probabilities, they’ve (or the statistical output they use) had historically been very conservative with predicting high amplitude ENSO events in either direction - them not saying a strong El Niño was likely in 2015 after the record breaking MJO pulse is an example of such. It’s obviously not certain but this is also the most obvious strong El Niño signal since 2015, and probably only exceeded by 2015 in my ~20 years following ENSO.

[WeatherBoy2000]

Nino 3.4 ssts have been rapidly rising since the beginning of the month:



Warmth that has surfaced in the nino 1+2 is spreading further west:





Regardless of intensity, el nino seems likely later this year unless something unexpected happens.

[cycloneye]

 https://x.com/jnmet/status/2024637613492113443