2024 ENSO Updates

[Kingarabian]

MJO is in the region but there are some strong daily negatives on the SOI this week. Has pushed the 30 day SOI back in negative territory.

They’re about bottoming now and should head back up shortly. What’s been driving the recent strong -SOI days have been very high Darwin SLPs. For those who don’t follow the SOI closely, a developing La Niña favors +SOIs in late spring and especially summer+. AN Tahiti SLP and BN Darwin SLP correlates to +SOI.

But recent Darwin SLPs have been anything but low. On the contrary, we just had 2 days of 1017.55+ with today in highly rarified territory at 1017.85. How rare is 1017.85?

Since 1991 and prior to today, there had been only 4 days with Darwin SLP of 1017.85+:

1018.35: June 22, 2004
1017.90: July 25, 2023
1017.90: Aug 5, 2023
1017.85: Aug 12, 1994

Note that all of these other 4 1017.85+ Darwin days were during an incoming or already existent 1st year El Niño. That’s far from the case now.

Since 1991 there’s been only one day during a year with a first year Niña immediately following a Nino that had a Darwin SLP >1017 mb: the 1017.15 mb of Aug 12, 1995.

For Niña following Nino, highest daily Darwin SLP:

1995: 1017.15
1998: 1015.35
2005: 1016.00
2007: 1016.00
2010: 1014.65
2016: 1015.25

And it's been correlating with stubborn positive Nino 3.4 anomalies at the surface and subsurface.

What's interesting is that during incoming La Nina's, in July the MJO slows down and amplifies just between the IO and the MC. Instead it seems that it will be getting stronger over the Pacific. This is a crucial MJO passage because if it can get stronger over the MC vs the Pacific, weak La Nina is pretty much gauranteed for ASO.

[cycloneye]

The July run of the ENSO models remain at borderline cold neutral / weak La Niña thru the peak of the season and by late September or October is when a weak La Niña comes.

[Blown Away]

The July run of the ENSO models remain at borderline cold neutral / weak La Niña thru the peak of the season and by late September or October is when a weak La Niña comes.

https://i.imgur.com/5sjt8jC.jpeg

+NAO + Cool Neutral + Extreme SST’s moving into La Niña during ASO…
NE Caribbean, Bahamas, SFL, Carolinas, NGOM, TX better be ready!!! Wow what a combo for an historic season… JMHO

[LarryWx]

The ENSO weeklies are still about where they were two months ago for all regions with Nino 3.4 still at +0.2. It literally looks like a very weak Modoki El Niño although that’s not taking into account how they are relative to very warm global tropical SSTs (need to subtract ~~0.6):

17JUL2024 21.2-0.5 25.7-0.1 27.5 0.2 29.4 0.6

[LarryWx]

The brand new Australian BoM model is the same as the prior run, with a weak dip to -0.2 for SON:

http://www.bom.gov.au/climate/ocean/out ... ion=NINO34


Although it was absolutely awful last year by being way too warm, I have to give credit when credit is due as this model has been spot on with a June/July pause in cooling since way back in late March:

http://www.bom.gov.au/climate/ocean/out ... o34.hr.png

[SFLcane]

 https://x.com/commoditywx/status/1815437944926470334

[cycloneye]

Things are cooling more faster lately.

 https://x.com/BenNollWeather/status/1815714261349581209

[cycloneye]

Very interesting post from Dr Ben Noll about the global tempeeratures at warm levels that may not let ENSO to dip into a bonifide La NIña.

Here is the post at X:

The relative Niño Index shows a full-fledged La Niña developing over the next few months while the traditional index shows a weak, borderline event.

In a warming world, it's becoming more difficult for seas to get cool enough to register a La Niña.

The relative index helps forecasters to navigate this challenge and understand where convection is likely to be favored.

The current ENSO event will be an interesting case, as many organizations that rely on the traditional index for classification may find that it falls short of the La Niña threshold.

The relative index (and atmosphere), however, may have other plans...

 https://x.com/BenNollWeather/status/1815714266357617123

[WeatherBoy2000]

 https://x.com/PaulRoundy1/status/1816913123502358642

[Iceresistance]

Nina? What La Nina?

 https://x.com/WxPatel/status/1816981513420124267

[DorkyMcDorkface]

Nina? What La Nina?

 https://x.com/WxPatel/status/1816981513420124267

We're still in line for one to develop, but we're definitely looking at a much weaker event than what much of the seasonal guidance depicted a few months ago.

[IcyTundra]

Nina? What La Nina?

 https://x.com/WxPatel/status/1816981513420124267

Maybe we will get La Nina for the winter

[cycloneye]

The July run of the ENSO models remain at borderline cold neutral / weak La Niña thru the peak of the season and by late September or October is when a weak La Niña comes.

https://i.imgur.com/5sjt8jC.jpeg

The ENSO models look to be right with the borderline Neutral / weak la niña that I described thru ASO.

[Kingarabian]

Back to back -20s or lower on the SOI. Looks like July will close out in negative territory. Pretty far from a La Nina state.

[LarryWx]

Back to back -20s or lower on the SOI. Looks like July will close out in negative territory. Pretty far from a La Nina state.

That will continue the string of neutral months since Mar. There has yet to be a Ninaish SOI (say +5+). We’ll see whether or not August is the first one.

The prior transitions from Nino to Niña were similarly slow in 2016, 2007, 2005, 1995, 1983, 1970, and 1954. All of those peaked only weak or low end moderate La Niña on an ONI basis except the strong of 2007. But the transitions in 2010, 1998, 1988, 1973, and 1964 already had solidly +SOI by May or June. Of those faster transitions, all ended up with a strong ONI based La Nina peak except the weak peak of 1964.

So what this all tells me is that due to them tending to be a leading indicator, recent months of SOIs are favoring a weak to low end moderate Niña peak later this year at most vs high end moderate to strong (ONI basis):

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

Meanwhile, however, Nino 3.4 OISST anomalies have finally cooled sharply (0.40) the last 3 days. This is the fastest 3 day cooling since the similar rapid cooling from Apr 9 to Apr 12:

https://cyclonicwx.com/data/sst/ssta_graph_nino34.png

Today’s NOAA weekly update (which is actually for last calendar week averaged out) cooled Nino 3.4 anomalies by 0.1C to +0.1C. I expect a bigger drop in next Monday’s weekly as of now. A drop of 0.2 to 0.3 looks quite possible. That would mean the first negative OISST 3.4 weekly since March of 2023. We’ll see as sometimes rapid drops are followed by a temporary “dead-cat” bounce.

[LarryWx]

The OISST based Nino 3.4 anomaly is still in a free fall. It just dropped another 0.1 and has now dropped a whopping 0.5C over the last 4 days to -0.33! That’s the fastest 4 day drop back to at least 2022! The equivalent RONI snapshot is quite possibly already approaching moderate Niña territory.

https://cyclonicwx.com/data/sst/ssta_graph_nino34.png

[Kingarabian]

CDAS has dropped below -0.5C.

[Kingarabian]

SOI for July was -5.8. That's pretty wild considering we were headed for a full blown La Nina by ASO. That being said the SOI will likely continue dropping this week. This poor atmospheric coupling likely means Nino 3.4 will remain near or above -0.5C, which would be a worst case scenario for the Atlantic hurricane season allowing for either a hyperactive or destructive season.

[Kingarabian]

Nino 3.4 is down to -0.2C per this weeks update.

[cycloneye]

Trades will intensify caising la niña to come very soon.

 https://x.com/MJVentrice/status/1821268009023107330