E.N.S.O. Discussion

[sebastiaan1973]

NOAA declares return of La Niña - The Washington Post 

https://www.washingtonpost.com/weather/2021/10/14/la-nina-winter-forecast/

[summer blizzard]

13OCT2021 - Niño 3: -0.7, Niño 3.4: -0.8, Niño 4: -0.5

[summer blizzard]

20OCT2021 - Niño 3: -0.8, Niño 3.4: -0.8, Niño 4: -0.6

[summer blizzard]

I believe that the appropriate word is.. geronimo. Back below -1. 

27OCT2021 - Niño 3: -0.9, Niño 3.4: -1.1, Niño 4: -0.5

October ONI looks like -0.8. 

ASO ONI looks like -0.4/-0.5. 

Sub-surface suggests we may last a while. 

Edited November 1, 2021 by summer blizzard

[summer blizzard]

03NOV2021 - Niño 3: -0.7, Niño 3.4: -1.0, Niño 4: -0.7

[knocker]

La Niña conditions are considered to be present in the equatorial Pacific.

La Niña conditions are more likely to continue (60%) until the end of boreal winter than not to continue (40%).

In October 2021, the NINO.3 SST was below normal with a deviation of -0.7°C (Table and Fig.3). SSTs in the equatorial Pacific were above normal in the western part and below normal in the central and eastern parts (Fig.4 and Fig.6). Subsurface temperatures were above normal in the western part and below normal in the central and eastern parts (Fig.5 and Fig.7). In the atmosphere, convective activity near the date line over the equatorial Pacific was below normal and easterlies in the lower troposphere (i.e., trade winds) over the central equatorial Pacific were stronger than normal (Fig.8, Fig.9, Fig.10). These oceanic and atmospheric conditions are consistent with features commonly seen in past La Niña events. La Niña conditions are considered to be present in the equatorial Pacific.

http://ds.data.jma.go.jp/tcc/tcc/products/elnino/outlook.html

[summer blizzard]

Sub-surface came in at -1.6C in October, the most negative value since Nov 10.

[knocker]

Global Ocean Monitoring: Recent Evolution, Current Status, and Predictions

https://www.cpc.ncep.noaa.gov/products/GODAS/

[SqueakheartLW]

We seem to have rapidly swung from a CP La Nina to an EP La Nina in recent times as the tropical tidbits charts below show

This had got me thinking about whether there had been any years where a La Nina started out as a CP event then progressed more to an EP event as the season progressed. I was surprised to find a few example years in fact.

I have grouped them up into two types. The first are where the coldest anomalies shift east but the overall ENSO pattern remains colder than average overall throughout the featured period. The second group are ones where warmer anomalies feature mainly in either NINO 4 late on or NINO 1+2 early on or an El Nino is on the way the following year and a general warmup is shown later on.

I have included lines to show the general progression from a CP event to more of an EP event

Group 1 - Cold ENSO throughout with eastward progression of coldest anomalies

As you can see here the ENSO regions generally remain colder than average or we get to average at the very warmest

Group 2 - CP to EP Cold ENSO but with some warmer anomalies at times late on or in NINO 4 late or NINO 1+2 early

Our current monthly ENSO values and how they compare with Group 1 and Group 2

As you can see here we have a bit of Group 2 situation in the fact we had some warmer NINO 1+2 anomalies early on but these have now cooled. However this was only ENSO Neutral so you could say we also qualify for Group 1 too.

Now to compare each group to the CET anomalies of the featured years

Group 1 - Cold ENSO throughout with eastward progression of coldest anomalies

This cluster of winters contained some notable cold years such as 1878/79, 1879/80, 1916/17 and 1962/63. Here's how the anomalies averaged out and their result on the projected CET values vs the 1991-2020 average

For cold winter lovers this CP to EP La Nina or cold ENSO CP to EP is a very good signal for a colder than average winter. All months from December through to March had decent cold anomalies, especially the Januaries. If we are to keep the ENSO region cold for long enough then watch this space. We could be on for a classic cold winter.

Group 2 - CP to EP Cold ENSO but with some warmer anomalies at times late on or in NINO 4 late or NINO 1+2 early

This cluster of winters was smaller and only really contained one colder than average winter, 2008/09. Here's how the anomalies averaged out and their result on the projected CET values vs the 1991-2020 average.

For cold winter lovers this signal is bad news in general as it would seem any influence from warmer ENSO values mutes the colder signal for these winters, especially for February and March. What this means is if we want a colder winter we don't want to see an early development of an EL Nino next year or any significant warm up of any of the ENSO regions before spring at the very earliest but better still next summer to keep the warmer ENSO influence off the up coming winter.

[Cold Winter Night]

47 minutes ago, SqueakheartLW said:

What this means is if we want a colder winter we don't want to see an early development of an EL Nino next year or any significant warm up of any of the ENSO regions before spring at the very earliest but better still next summer to keep the warmer ENSO influence off the up coming winter.

Perhaps I'm reading this the wrong way, but next year's (spring/summer) ENSO state can obviously not influence this upcoming winter. The atmosphere can only respond to current ocean temperatures and energy flows etc, and does not anticipate future developments.

If you mean that we don't want to see a quick warmup from La Nina to El Nino during the winter months, I get it, but I don't think that is forecasted anywhere.

But, again, perhaps, I read your post the wrong way!

 

[Singularity]

I believe what SqueakheartLW means is, we don't want to see the La Nina relax much during Jan-Feb.

Current model forecasts indicate some relaxation but still solidly within La Nina territory until no sooner than March.

The shift to a more EP focused La Nina certainly is of interest - it has contributed to a decidedly nippy look to my analogue year composites for Jan-Feb. Not something I'd previously been expecting to see for this winter!

[damianslaw]

41 minutes ago, Singularity said:

I believe what SqueakheartLW means is, we don't want to see the La Nina relax much during Jan-Feb.

Current model forecasts indicate some relaxation but still solidly within La Nina territory until no sooner than March.

The shift to a more EP focused La Nina certainly is of interest - it has contributed to a decidedly nippy look to my analogue year composites for Jan-Feb. Not something I'd previously been expecting to see for this winter!

Be interested to know which ones... 95-96 perhaps?

[summer blizzard]

10NOV2021 - Niño 3: -0.6, Niño 3.4: -0.8, Niño 4: -0.7

[summer blizzard]

17NOV2021 - Niño 3: -1.1, Niño 3.4: -1.0, Niño 4: -0.7

[summer blizzard]

24NOV2021 - Niño 3: -0.8, Niño 3.4: -0.7, Niño 4: -0.7

[knocker]

Issued 7 December

La Niña firmly established in the tropical Pacific

La Niña is firmly established in the tropical Pacific. Climate models suggest this La Niña will persist until the late southern hemisphere summer or early autumn 2022. La Niña events increase the chance of above average rainfall across much of northern and eastern Australia during summer.

Most El Niño–Southern Oscillation (ENSO) indicators show clear La Niña patterns. Sea surface temperatures in the tropical Pacific have cooled to La Niña thresholds, with climate model outlooks expecting them to cool further. In the atmosphere, cloud and wind patterns are typical of La Niña, indicating the atmosphere is responding to the changes in ocean temperatures. This feedback process is known as "coupling", and it means La Niña conditions are now expected to be locked in until at least the end of summer.

The negative Indian Ocean Dipole (IOD) is near its end, with IOD index values in the neutral range. However, some signs of the negative IOD persist with increased cloud over the eastern Indian Ocean and strengthened westerly winds. Climate models predict the IOD will remain neutral for the coming months, consistent with its typical seasonal cycle.

The Madden–Julian Oscillation (MJO) has recently entered the western Pacific and strengthened. The MJO is forecast to progress eastwards across the western Pacific over the coming fortnight, which increases the likelihood of above average cloudiness and rainfall across northern Australia and the western Pacific. It also increases the chance that the monsoon will develop in the Australian region in the next week or two—a little earlier than normal.

http://www.bom.gov.au/climate/enso/

[summer blizzard]

01DEC2021 - Niño 3: -1.2, Niño 3.4: -0.9, Niño 4: -0.7

Nov ONI was around -0.85 so not much of an increase on October. 

SON ONI was -0.8. 

[summer blizzard]

08DEC2021 - Niño 3: -1.4, Niño 3.4: -1.1, Niño 4: -0.9

[summer blizzard]

08DEC2021 - Niño 3: -1.2, Niño 3.4: -1.1, Niño 4: -1.0

[summer blizzard]

Interestingly the forcing has progressed to the west Pacific, if this persists it probably means a faster decline for this Nina event albeit in the short term it increases the pressure gradiant. 

[summer blizzard]

22DEC2021 - Niño 3: -1.2, Niño 3.4: -1.1, Niño 4: -0.8

[summer blizzard]

Cold and warm wave at the same time, not common.

[Don]

2 hours ago, summer blizzard said:

Cold and warm wave at the same time, not common.

Hmm, even more challenges for forecasting?

Edited December 29, 2021 by Don

[SqueakheartLW]

On 29/12/2021 at 21:13, summer blizzard said:

Cold and warm wave at the same time, not common.

Wonder if that is the start of the predicted Modoki El Nino for later in the year. After all I do remember posting this somewhere a source I found which solidly predicted a Modoki El Nino to form in 2022.

[Don]

13 minutes ago, SqueakheartLW said:

Wonder if that is the start of the predicted Modoki El Nino for later in the year. After all I do remember posting this somewhere a source I found which solidly predicted a Modoki El Nino to form in 2022.

Hopefully as a Modoki El Nino is thought to increase the chances of colder winters in north west Europe.  Thinking about next winter already lol! 

Edited January 2, 2022 by Don