ENSO Updates (2007 thru 2023)

[aspen]

Do they think this La Niña could last into next summer/fall? We don't need a 6th active Atlantic season in a row... We've had enough storms to deal with the last 5 years

That’s exactly what I’ve been wondering too. Even if a full-blown La Niña doesn’t persist into ASO 2021 (I doubt a significant ENSO event could last that long), could there still be a cool neutral ENSO around? What impact would a La Niña in winter 2020-21 have on the 2021 Atlantic hurricane season, if any?

[ElectricStorm]

Do they think this La Niña could last into next summer/fall? We don't need a 6th active Atlantic season in a row... We've had enough storms to deal with the last 5 years

That’s exactly what I’ve been wondering too. Even if a full-blown La Niña doesn’t persist into ASO 2021 (I doubt a significant ENSO event could last that long), could there still be a cool neutral ENSO around? What impact would a La Niña in winter 2020-21 have on the 2021 Atlantic hurricane season, if any?

I remember the El Niño lasted awhile in 2014 and 2015. But then again that was a "Super Niño". I guess "normal" Niños and Niñas don't last that long?

[Kingarabian]

Do they think this La Niña could last into next summer/fall? We don't need a 6th active Atlantic season in a row... We've had enough storms to deal with the last 5 years

That’s exactly what I’ve been wondering too. Even if a full-blown La Niña doesn’t persist into ASO 2021 (I doubt a significant ENSO event could last that long), could there still be a cool neutral ENSO around? What impact would a La Niña in winter 2020-21 have on the 2021 Atlantic hurricane season, if any?

Yes it's certainly possible. It's always hard to predict anything ENSO related but If this La Nina can remain moderate vs strong heading into the spring there is a chance of a double dip La Nina. Strong El Nino or La Ninas tend to trigger their opposites once they reach maturity. There's a possibility this La Nina event does not become strong since the SOI has been consistently been +9 vs +15 or +20. First things first though is to keep the WWB's at a minimum.

[Kingarabian]

January is now in range for the 3 month CFS. Shows a period of relaxed trades over the dateline in late November but has a strong trade burst in January as well. I think for an early outlook, there's increasing odds for a cool-neutral/ La Nina during the 2021 Hurricane season.

[CyclonicFury]

January is now in range for the 3 month CFS. Shows a period of relaxed trades over the dateline in late November but has a strong trade burst in January as well. I think for an early outlook, there's increasing odds for a cool-neutral/ La Nina during the 2021 Hurricane season.

https://i.imgur.com/6mGNzA2.png

Seems plausible since ENSO climatology often favors -ENSO periods lasting at least 2 years. It is rare to directly go from a moderate-strong La Niña to an El Niño. The most favorable window for WWBs is in the spring, and with a La Niña atmosphere firmly entrenched it's unlikely we will see a rapid warming in the spring. During double dip La Niñas, the second event is usually weaker than the first, with a few exceptions.

[Kingarabian]

January is now in range for the 3 month CFS. Shows a period of relaxed trades over the dateline in late November but has a strong trade burst in January as well. I think for an early outlook, there's increasing odds for a cool-neutral/ La Nina during the 2021 Hurricane season.

https://i.imgur.com/6mGNzA2.png

Seems plausible since ENSO climatology often favors -ENSO periods lasting at least 2 years. It is rare to directly go from a moderate-strong La Niña to an El Niño. The most favorable window for WWBs is in the spring, and with a La Niña atmosphere firmly entrenched it's unlikely we will see a rapid warming in the spring. During double dip La Niñas, the second event is usually weaker than the first, with a few exceptions.

But there's also some conflicting variables that may hold off a double dip La Nina. There's a decent +PDO signature as well as a weak -PMM signature. It's super strange to see a PDO signature like this in a moderate La Nina. Maybe 2017 is sorta similar?

Part of the reason why Hawaii is in a drought right now.

[weeniepatrol]

Becoming quite a significant event compared to 2016-17 and 2017-18:

[CyclonicFury]

-1.4°C is the coldest weekly Niño 3.4 value since February 2011! We are witnessing a bonafide La Niña this fall. The 2016 and 2017 events were fairly weak.

It's somewhat surprising to see a Niña this strong without a significant Niño the previous winter. This Niña will likely end up at least in the moderate category.

[ElectricStorm]

-1.4°C is the coldest weekly Niño 3.4 value since February 2011! We are witnessing a bonafide La Niña this fall. The 2016 and 2017 events were fairly weak.

It's somewhat surprising to see a Niña this strong without a significant Niño the previous winter. This Niña will likely end up at least in the moderate category.

I've always wondered... Why are the Niño regions numbered 1,2,3,3.4, and 4? How come it's not just 1-5?

[ClarCari]

What are some similarities so far from this year’s event to first year La Niña events such as 04-05, and 16-17.

My gut is really feeling like next year may see more intensity and at least similar activity in names to this year. Even a weaker La Niña event could produce even worse activity in year 2(05,17) vs year 1(04,16) which is exactly what happened in those periods. What did those year 1’s ENSO conditions look like that 2020 is showing any similarities to?

[Chris90]

What are some similarities so far from this year’s event to first year La Niña events such as 04-05, and 16-17.

My gut is really feeling like next year may see more intensity and at least similar activity in names to this year. Even a weaker La Niña event could produce even worse activity in year 2(05,17) vs year 1(04,16) which is exactly what happened in those periods. What did those year 1’s ENSO conditions look like that 2020 is showing any similarities to?

2005 wasn't a second year niña, 2004 was modoki El Niño, and 2005 started the hurricane season in warm neutral territory and progressively got cooler as the season continued on. 2016 was a Niña that went back into warm territory, in fact, for a little while there it appeared that the 2017 hurricane season would be a Niño year, it trended into cool neutral to a Niña as the season progressed.

My personal theory is that it isn't so much being in an actual full fledged Niña that makes the Atlantic favorable, I think the most favorable setup for the ATL is when ENSO goes from warm neutral to cool neutral during the heart of the season. ENSO took a fairly deep dive into Niña territory during the heart/latter portion of the 2005 and 2017 hurricane seasons, and I think that is what contributed to them being so hyperactive and generating such intense storms. I think part of the reason why this season kept beating earliest named storm records and has generated such a high number of storms but has failed to generate storms of the intensity to match storms from '05 or '17 is because the Niña came on a little too early and a little too strong. This year posted a negative trimonthly before both 2005 and 2017, and the negative trimonthly for JAS 2020(July-August-September) is a colder value than JAS for either 2005 or 2017.

I think the developing Niña just provided the ATL with peak conditions a little too early this year, which is why I believe we saw such a record breaking early season in June and July. If the Niña had been delayed 2-3 months I think we would have possibly seen a CV season that was more comparable to 2017 and storms like Nana might have achieved much higher intensities.

This is just my personal thoughts though and I am in no way an expert.

Regarding next year though, I think it's going to depend heavily on how ENSO evolves over the next few months until we get to summer 2021. The last time I looked, which honestly was a couple weeks ago, there was warmth in the subsurface in the western ENSO region (Niño 4), but it's going to need the MJO to behave during the winter and spring in a way that favors WWBs (westerly wind bursts) so that way they can warm the ENSO regions. If we start hurricane season 2021 in a warm ENSO state that heads towards cooler territory during the latter portions of the season I think that is the most likely ENSO scenario to produce a '05/'17-esque season. If the Niña holds through the winter and spring and into and throughout the hurricane season, I think it will help facilitate another active ATL season but might limit the number of majors and their intensity. Could still be prolific with 3-4 majors, I just think they'll lack the super intensity of a Katrina/Rita/Wilma/Irma/Maria. Or ENSO might start to evolve to a warm state during the winter or spring and continue throughout the hurricane season, in which case the safest bet is to go with the EPAC/CPAC for being the more active basin.

Personal, long range, gut feeling forecast with no science involved? I think by summer 2021 we'll be trending towards warmer ENSO territory and EPAC/CPAC will be the more active basin next year.

[ElectricStorm]

What are some similarities so far from this year’s event to first year La Niña events such as 04-05, and 16-17.

My gut is really feeling like next year may see more intensity and at least similar activity in names to this year. Even a weaker La Niña event could produce even worse activity in year 2(05,17) vs year 1(04,16) which is exactly what happened in those periods. What did those year 1’s ENSO conditions look like that 2020 is showing any similarities to?

2005 wasn't a second year niña, 2004 was modoki El Niño, and 2005 started the hurricane season in warm neutral territory and progressively got cooler as the season continued on. 2016 was a Niña that went back into warm territory, in fact, for a little while there it appeared that the 2017 hurricane season would be a Niño year, it trended into cool neutral to a Niña as the season progressed.

My personal theory is that it isn't so much being in an actual full fledged Niña that makes the Atlantic favorable, I think the most favorable setup for the ATL is when ENSO goes from warm neutral to cool neutral during the heart of the season. ENSO took a fairly deep dive into Niña territory during the heart/latter portion of the 2005 and 2017 hurricane seasons, and I think that is what contributed to them being so hyperactive and generating such intense storms. I think part of the reason why this season kept beating earliest named storm records and has generated such a high number of storms but has failed to generate storms of the intensity to match storms from '05 or '17 is because the Niña came on a little too early and a little too strong. This year posted a negative trimonthly before both 2005 and 2017, and the negative trimonthly for JAS 2020(July-August-September) is a colder value than JAS for either 2005 or 2017.

I think the developing Niña just provided the ATL with peak conditions a little too early this year, which is why I believe we saw such a record breaking early season in June and July. If the Niña had been delayed 2-3 months I think we would have possibly seen a CV season that was more comparable to 2017 and storms like Nana might have achieved much higher intensities.

This is just my personal thoughts though and I am in no way an expert.

Regarding next year though, I think it's going to depend heavily on how ENSO evolves over the next few months until we get to summer 2021. The last time I looked, which honestly was a couple weeks ago, there was warmth in the subsurface in the western ENSO region (Niño 4), but it's going to need the MJO to behave during the winter and spring in a way that favors WWBs (westerly wind bursts) so that way they can warm the ENSO regions. If we start hurricane season 2021 in a warm ENSO state that heads towards cooler territory during the latter portions of the season I think that is the most likely ENSO scenario to produce a '05/'17-esque season. If the Niña holds through the winter and spring and into and throughout the hurricane season, I think it will help facilitate another active ATL season but might limit the number of majors and their intensity. Could still be prolific with 3-4 majors, I just think they'll lack the super intensity of a Katrina/Rita/Wilma/Irma/Maria. Or ENSO might start to evolve to a warm state during the winter or spring and continue throughout the hurricane season, in which case the safest bet is to go with the EPAC/CPAC for being the more active basin.

Personal, long range, gut feeling forecast with no science involved? I think by summer 2021 we'll be trending towards warmer ENSO territory and EPAC/CPAC will be the more active basin next year.

I hope so, I prefer seasons where the EPAC is more active than the Atlantic. EPAC generally produces more storms, and there's less land to hit out there.

[ClarCari]

What are some similarities so far from this year’s event to first year La Niña events such as 04-05, and 16-17.

My gut is really feeling like next year may see more intensity and at least similar activity in names to this year. Even a weaker La Niña event could produce even worse activity in year 2(05,17) vs year 1(04,16) which is exactly what happened in those periods. What did those year 1’s ENSO conditions look like that 2020 is showing any similarities to?

2005 wasn't a second year niña, 2004 was modoki El Niño, and 2005 started the hurricane season in warm neutral territory and progressively got cooler as the season continued on. 2016 was a Niña that went back into warm territory, in fact, for a little while there it appeared that the 2017 hurricane season would be a Niño year, it trended into cool neutral to a Niña as the season progressed.

My personal theory is that it isn't so much being in an actual full fledged Niña that makes the Atlantic favorable, I think the most favorable setup for the ATL is when ENSO goes from warm neutral to cool neutral during the heart of the season. ENSO took a fairly deep dive into Niña territory during the heart/latter portion of the 2005 and 2017 hurricane seasons, and I think that is what contributed to them being so hyperactive and generating such intense storms. I think part of the reason why this season kept beating earliest named storm records and has generated such a high number of storms but has failed to generate storms of the intensity to match storms from '05 or '17 is because the Niña came on a little too early and a little too strong. This year posted a negative trimonthly before both 2005 and 2017, and the negative trimonthly for JAS 2020(July-August-September) is a colder value than JAS for either 2005 or 2017.

I think the developing Niña just provided the ATL with peak conditions a little too early this year, which is why I believe we saw such a record breaking early season in June and July. If the Niña had been delayed 2-3 months I think we would have possibly seen a CV season that was more comparable to 2017 and storms like Nana might have achieved much higher intensities.

This is just my personal thoughts though and I am in no way an expert.

Regarding next year though, I think it's going to depend heavily on how ENSO evolves over the next few months until we get to summer 2021. The last time I looked, which honestly was a couple weeks ago, there was warmth in the subsurface in the western ENSO region (Niño 4), but it's going to need the MJO to behave during the winter and spring in a way that favors WWBs (westerly wind bursts) so that way they can warm the ENSO regions. If we start hurricane season 2021 in a warm ENSO state that heads towards cooler territory during the latter portions of the season I think that is the most likely ENSO scenario to produce a '05/'17-esque season. If the Niña holds through the winter and spring and into and throughout the hurricane season, I think it will help facilitate another active ATL season but might limit the number of majors and their intensity. Could still be prolific with 3-4 majors, I just think they'll lack the super intensity of a Katrina/Rita/Wilma/Irma/Maria. Or ENSO might start to evolve to a warm state during the winter or spring and continue throughout the hurricane season, in which case the safest bet is to go with the EPAC/CPAC for being the more active basin.

Personal, long range, gut feeling forecast with no science involved? I think by summer 2021 we'll be trending towards warmer ENSO territory and EPAC/CPAC will be the more active basin next year.

Ahh guess I shoulda phrased it better, but I guess I meant that active ATL periods tend to come in pairs, sometimes with the first year dealing with a bit more shear, and El Niño-esque like issues that become less prominent the following year.
Appreciate your thorough analysis!! I still get confused about ENSO myself sometimes because of the terminology we use (warm-neutral-cold) that describes a specific area of Pacific SSTs and that La Niña isn’t really it’s own event more so that it’s really just an El Niño reversed

I have to say though, that unless some serious telling El-Niño patterns are able to persist soon, I can’t see the EPAC being more active than ATL until at least 2022. There appears to be other atmospheric conditions besides just the ENSO that caused crazy TC genesis in the ATL this season that are hard to imagine will go away that much, if at all, next year.
Depending on the patterns I think it’s possible we may see more intensity next year in both basins perhaps, but with the ATL still being more active overall. How many named storms will happen is impossible to tell, but what isn’t impossible is going Greek for the 2nd year in a row (that is if they don’t consider changing the naming system at the next Committee).
Of course alot of this is too far out to tell really right now.
The Winter and Spring ENSO will set the stage! I just have a feeling that the other favorable ATL conditions are gonna return next year when the seasonal favorability rolls around again and that a true El Niño event that will suppress ATL activity is not coming for another year and a half at least...

[CyclonicFury]

Since 1950, there have been 11 moderate or stronger La Niña events (as 2020-21 appears poised to do). Of these, only one year was followed by an El Niño event, a very weak one (1976-77), and this La Niña was already in its third year.

I think the best chance for a significant El Niño may not be until 2022 or 2023. I would be more optimistic about El Niño chances if this La Niña were weaker or a second year event, but first year significant La Niñas are usually followed by continued cool ENSO the next year.

[Kingarabian]

Models are showing the MJO waking up, with a stronger but quicker MJO event over the entire Pacific.


It's weak in amplitude but don't forget that the base state is now La Nina. So for it to reflect on RMM means it's a real event. Could slow the trades near the dateline.

If the MJO is not active enough all it'll do is increase the chances of cool neutral for summer 2021. Very hard to call a 2005->2006 ENSO transition right now.

[cycloneye]

 https://twitter.com/TylerJStanfield/status/1319295908161441792

[Kingarabian]

CFS has some westerly winds in the EPAC at the equator through the first 2 weeks of November. Could negate the erupting upwelling Kelvin wave a little and mix in some warmer anomalies at the subsurface. Still keeps strong trades over the dateline through mid January which is all that matters in ENSO.

[Dean_175]

This is becoming a fairly large ENSO event. I know the Atlantic hurricane season is a pretty big distraction , but I am surprised how quiet this thread is.

CFS is showing quite a robust La Niña at peak- with monthly anomalies potentially hitting -2.0C in December or January. There have been strong easterly wind anomalies over the Pacific for a while now. Very consistent positive ESOI ( Equatorial SOI) since March with September coming in with an impressive +1.3 ESOI.

[ClarCari]

WMO released their latest ENSO update a couple days ago I believe.
This is becoming quite a significant event going into the end of the year. Had the peak of this event been around now or a little earlier, I’d think there’d be more of a chance of some type of El Niño follow up by mid or late next season, but the fact this is peaking later means at best there’d be enough time to warm to a Cool-Neutral La-Nina or maybe Neutral for 2021 ATL Hurricane season. *shivers*

[weeniepatrol]

This week:

Nino 1+2: -1.1
Nino 3: -1.5
Nino 3.4: -1.7
Nino 4: -0.7