2021-2022 ENSO

[andyhb]

Speaking of La Nina, this is quite the rapid subsurface cooling occurring over the past month or so.

Now ahead of last year's pace at this time.

[George001]

1 hour ago, andyhb said:

Speaking of La Nina, this is quite the rapid subsurface cooling occurring over the past month or so.

Now ahead of last year's pace at this time.

Woah last year was a high end moderate/borderline strong La Niña and we are AHEAD of last years pace? A slightly later peaking and slightly weaker version of the 2010-2011 La Niña is not out of the question at this rate. 

[raindancewx]

It's a bit disingenuous to say we're ahead of last year. The warmth from April-June has to wash out fully first. More relevant is how the trend is from last year anyway. The way the similar cold below the surface has arrived in July is completely opposite last year both at depth (the 0-300m readings) and in an 2D East/West, North/South sense.

The La Nina of 2020-21 was really an April-March thing in terms of the subsurface. This event is probably an August or September start at this point, pending how long it lasts. The subsurface last year featured several giant rises and dips that coincided with huge changes in the seasonal US weather pattern. It's not a coincidence that the huge cold periods in the central/western US coincided with a flip from declining heat to rising heat both times (Oct and Feb were the flips in trend). One reason I had liked 2007-08 last year was for the double peak in the subsurface, in October and then January, it was very much like 2020-21. The idea that last year was a Moderate La Nina is still kind of silly to me, when the "-1.3" or whatever CPC uses for 2020-21 is based on a much warmer average for Dec-Feb than earlier La Ninas. In terms of actual SSTs, by coldest month or coldest month against constant averages, last year was warmer than roughly half of La Ninas. It's more of a weak event than a moderate one at the surface. Years like 2010-11 and 2011-12 had much more impressive peaks, especially given they followed a much stronger El Nino in 2009-10.

The subsurface was colder at the peak of the 2011-12, 2010-11, 2008-09, 2007-08, 1999-00, 1998-99, 1995-96, 1988-89, 1983-84 events compared to 2020-21. That's almost every La Nina since 1980...

[OHweather]

Just to go on the record, I tend to agree that this La Nina will be slightly weaker than last year's given the surface is running noticeably warmer, though it's quite possible August's sub-surface anomaly is around -1, which would put it pretty close to last year's sub-surface "peak"...my argument is that at least a weak La Nina is likely, nothing too much more. 

[EasternLI]

MEI is interesting. At -1.53 it's more negative than any time last year. But also, have to go back about a decade for a comparable number. 

https://psl.noaa.gov/enso/mei/data/meiv2.data

[George001]

13 hours ago, EasternLI said:

MEI is interesting. At -1.53 it's more negative than any time last year. But also, have to go back about a decade for a comparable number. 

https://psl.noaa.gov/enso/mei/data/meiv2.data

MEI is a good indicator, I like it since sometimes even though you have a La Niña at the surface the atmospheric response doesn’t reflect it. In my opinion that is a better measure than ONI since it takes the atmospheric response into account too, so if you have a La Niña that isn’t coupled with the atmosphere the MEI will reflect that. What the MEI tells me is the atmospheric response reflects that of a strong La Niña, and this MEI value is the lowest we have had since 2011. An MEI value this low during the summer is extremely unusual, as la ninas typically peak later so an MEI value this low this early has only been seen in extremely strong La Niña events. Going back and looking at previous summers with an MEI value -1 or below you get the years

2021, 2020, 2010, 1999, 1998, 1989, and 1988. The data I’m looking at only goes back to 1979. The following winters we had

2020-2021: moderate la nina both oni and mei

2010-2011: strong la nina by oni, super nina by mei (strongest nina on record)

1999-2000: strong La Niña by oni, high end moderate by mei

1998-1999: strong La Niña by oni, moderate by mei

1989-1990: cold neutral by oni, warm neutral by mei

1988-1989: strong La Niña by oni, moderate La Niña by mei

 

that is 5/6 winters with a -1 or below MEI by summer leading into a moderate or stronger La Niña by fall and winter. By ONI you get 4 strong ninas, one moderate Nina and one cold neutral, and by MEI you get one super nina, 4 moderate ninas and one warm neutral. In the dataset before 2021 the 3 lowest readings by MEI by this time of year were 2010, 1998, and 1988. All 3 of the following winters were at least moderate by Nina by mei, and all 3 were considered strong la ninas by oni. I am not convinced at all that this La Niña is going to be weak. This isn’t a perfect methodology due to small sample size issues, but i don’t think we should ignore that the 3 lowest mei readings since 1979 (but pre 2021) by summer all transitioned into strong la ninas by oni and at least moderate by mei. Also, it makes sense from a la nina climo point of view. Since la ninas tend peak in the fall or winter, when there is already a strong nina like atmospheric response in summer it would be expected that by fall and winter both the surface enso readings and atmosphere would reflect a strong La Niña.

[George001]

13 hours ago, EasternLI said:

MEI is interesting. At -1.53 it's more negative than any time last year. But also, have to go back about a decade for a comparable number. 

https://psl.noaa.gov/enso/mei/data/meiv2.data

This upcoming La Niña event reminds me of 2010-2011 even more now after seeing this MEI data.

[40/70 Benchmark]

On 8/7/2021 at 1:43 AM, OHweather said:

Just to go on the record, I tend to agree that this La Nina will be slightly weaker than last year's given the surface is running noticeably warmer, though it's quite possible August's sub-surface anomaly is around -1, which would put it pretty close to last year's sub-surface "peak"...my argument is that at least a weak La Nina is likely, nothing too much more. 

Agree. I value the MEI, but its important not to get too carried away with it. It just means that this particular ENSO event is well coupled with the atmosphere....its not an excuse to expect a strong la nina outcome with a weak ONI designation. However, I wouldn't hesitate to incorporate some moderate strength analogs despite ONI merely reflecting weak if that ends up being the case.

[raindancewx]

One thing I like to do this time of year to start to winnow down analogs is to look at objectively good tropical matches in Dec-Feb for the prior winter that are still objectively good matches in July. The winters of 1966-67, 2000-01, 2010-11 were close winter SST matches in the tropics, and 1967, 2001, and 2011 are still close in July. 1966-67 was probably the best of the three overall for US conditions, but we had an exaggerated version of that pattern in winter. Winter 2020-21 was kind of opposite the very cold Dec 2010/2000 pattern, which is I 'knew' would be unlikely heading into last winter. The current July, and August pattern so far pretty is close to 1967 nationally.

The blend of 1967-68, 2001-02, 2011-12 is a very weak La Nina in winter that is coldest in Nino 3, warmest in Nino 4, and then weakens sharply in Feb-Mar from the east. You can see the big -PDO signature with very warm water near Japan, and some cold water by the equator in the Atlantic like we've had in recent weeks. I don't think this look is quite right though, and I don't think the US temperature pattern it produces is correct either.

                
We're still not that close to long-term La Nina conditions at the surface.
Nino 3.4 needs to be around 26.15C in August to be even -0.5C against 
1951-2010 averages. Nino 1.2 remaining warm into October against a -PDO base 
state in March-August tends to precede a flip to a more +PDO state in Nov-Apr.
Something that needs to be watched. 

                 Nino1+2      Nino3        Nino34        Nino4
 Week          SST SSTA     SST SSTA     SST SSTA     SST SSTA

 09JUN2021     23.2-0.0     26.7-0.0     27.8-0.0     28.9-0.1
 16JUN2021     23.3 0.4     26.0-0.5     27.2-0.5     28.8-0.2
 23JUN2021     22.9 0.2     26.3-0.0     27.6-0.0     29.0 0.0
 30JUN2021     22.6 0.3     26.2 0.0     27.5-0.1     28.8-0.1
 07JUL2021     22.2 0.1     26.0-0.0     27.4-0.0     28.9-0.1
 14JUL2021     22.2 0.4     25.9 0.1     27.2-0.1     28.6-0.4
 21JUL2021     22.1 0.6     25.2-0.4     26.8-0.5     28.5-0.4
 28JUL2021     22.1 0.8     25.1-0.4     26.7-0.4     28.7-0.1
 04AUG2021     21.7 0.7     25.1-0.2     26.7-0.3     28.6-0.2

 05AUG2020     19.8-1.3     24.6-0.7     26.3-0.7     28.4-0.4

 

I do think these years are likely to continue to watch well to 2021 in Nino 3.4 through at least December.

You can see August should be near the speculative 26.5C going by week one. At 26.1C in September that would be the initiation of the La Nina if the blend isn't too cold. The current big time drop off in the subsurface will likely flatten or reverse a bit in a few weeks, as that water works up to the surface. I think you'll see a pattern fake in late September-October when that happens before a transition in November.  My guess is this is another cold ENSO with a relatively early surface peak. The 2020-21 event was much more impressive in the Fall than the Winter by historical standards. Something like a top 1/3 cold event in October or November, and then well below that by the end of the winter.              

[OHweather]

6 hours ago, 40/70 Benchmark said:

Agree. I value the MEI, but its important not to get too carried away with it. It just means that this particular ENSO event is well coupled with the atmosphere....its not an excuse to expect a strong la nina outcome with a weak ONI designation. However, I wouldn't hesitate to incorporate some moderate strength analogs despite ONI merely reflecting weak if that ends up being the case.

Agree, when looking for analogs, unless it's an exceptionally strong event, I'll usually allow expected ENSO state plus or minus one (i.e. at the moment I'm playing with analogs ranging from cool neutral to moderate La Nina). I'll also heavily weigh things like QBO, whether an ENSO event is west or east weighted, the Indian Ocean Dipole and where lower-frequency tropical forcing is in the months leading into winter. So this year I'm playing with cool ENSO - moderate La Ninas, and looking (if possible) for ones with an easterly QBO, a negative IOD and a warm west Pac. Also, the lower frequency forcing this summer so far has been most favored over the western Pacific. It's an interesting set of analogs, with years like 74-75, 00-01, 05-06, 12-13 and 17-18 showing up in there, but also a disaster like 11-12 hitting many of those too. 

[raindancewx]

We haven't had it in a while, but there are a lot of older years when the SSTs in Nino 3/3.4 are very cold, but only very briefly. That's my fear for the La Nina consensus - it gets very cold again in Nino 3/3.4 in the Fall, and then it sharply weakens. It's more common for the sea surface temps to get very cold/warm, but only briefly when the peak anomalies are closer to Halloween or Thanksgiving than Christmas (ala the observations of the fisherman per normal ENSO).

 

[40/70 Benchmark]

13 hours ago, OHweather said:

Agree, when looking for analogs, unless it's an exceptionally strong event, I'll usually allow expected ENSO state plus or minus one (i.e. at the moment I'm playing with analogs ranging from cool neutral to moderate La Nina). I'll also heavily weigh things like QBO, whether an ENSO event is west or east weighted, the Indian Ocean Dipole and where lower-frequency tropical forcing is in the months leading into winter. So this year I'm playing with cool ENSO - moderate La Ninas, and looking (if possible) for ones with an easterly QBO, a negative IOD and a warm west Pac. Also, the lower frequency forcing this summer so far has been most favored over the western Pacific. It's an interesting set of analogs, with years like 74-75, 00-01, 05-06, 12-13 and 17-18 showing up in there, but also a disaster like 11-12 hitting many of those too. 

I don't feel like we are going to see a monster +AO, though, so while 2011-2012 may be a viable analog....I wouldn't be too concerned about such a dire outcome.

[raindancewx]

The patterns nationally are still reminiscent of 1967 to me - which makes sense given that it is probably the closest SST match for 2021 overall.

[OHweather]

10 hours ago, 40/70 Benchmark said:

I don't feel like we are going to see a monster +AO, though, so while 2011-2012 may be a viable analog....I wouldn't be too concerned about such a dire outcome.

I agree with you on the AO. But if anything that analog highlights...E QBO La Ninas tend to have a somewhat flatter N Pacific ridge than W QBO La Ninas, which does open the risk for the PV to sink into Alaska. So, it's a concern. There is at least some signal for a -NAO on analogs and models, so I do have some cautious optimism as long as the Pacific can behave. 

26 minutes ago, raindancewx said:

The patterns nationally are still reminiscent of 1967 to me - which makes sense given that it is probably the closest match for 2021 overall.

That year does have some interesting ENSO and QBO similarities to this year. There are other things (Atlantic SSTs and off-equator SSTs, along with summer tropical forcing) that differ from this year and kind of turn me off to it as an analog, but the winter look is somewhat similar to other years that I'm playing with WRT ridging probably centered W of Alaska with a -NAO.

[raindancewx]

At this point I'm generally looking at 20-30 years for the winter of the last 100. 

I'm already close to throwing out some La Ninas just based on hurricane activity which doesn't seem to be super amped, or super low in the Atlantic through mid-August. Last year had nine tropical storms by this date, ten by 8/13. A lot of years like 1983 or 1974 or 1933 or 2017 are at one extreme by ACE/total activity.

I like to focus on rareness in various signals. So what has been rare this year?

- Record +WPO in Jan/Mar (WPO >1.5 in March: 1977, 1985, 1991, 2010, and probably several years in the 1930s)

- Record +PNA in August (PNA >1.5 in August: (1958, 1960, 1977, 1990, 1999, 2004, 2007, 2020)

- Record heat and cold in the Southwest in Summer (Highs <=70F, AND >=100F June in ABQ: (0 but 1937 is closest)

- Unusual heat Northwest in Summer (1960, 1967, 2013)

- Rapidly Rising solar activity in a La Nina  (1955, 1956, 1988, 1998, 1999, 2010, 2011) with many near Ninas too.

Which years show up at least twice? 1960, 1977, 1999, 2010. That blend kind of looks like a 1967/2013, and those years have been decent SST matches.

 

 

[40/70 Benchmark]

13 hours ago, OHweather said:

I agree with you on the AO. But if anything that analog highlights...E QBO La Ninas tend to have a somewhat flatter N Pacific ridge than W QBO La Ninas, which does open the risk for the PV to sink into Alaska. So, it's a concern. There is at least some signal for a -NAO on analogs and models, so I do have some cautious optimism as long as the Pacific can behave. 

That year does have some interesting ENSO and QBO similarities to this year. There are other things (Atlantic SSTs and off-equator SSTs, along with summer tropical forcing) that differ from this year and kind of turn me off to it as an analog, but the winter look is somewhat similar to other years that I'm playing with WRT ridging probably centered W of Alaska with a -NAO.

Yea, that was the primary impetus behind that winter being a no-show. Bit of a conflicting signal there, as easterly QBO is generally more conducive to high  latitude blocking. It will bare watching, but I think the fact that this event should remain pretty weak and peak early will help our cause.

I am not at all pessimistic and feel relatively confident.

[40/70 Benchmark]

13 hours ago, raindancewx said:

The patterns nationally are still reminiscent of 1967 to me - which makes sense given that it is probably the closest SST match for 2021 overall.

Makes sense to me, as well because I do think that is a very good analog.

[40/70 Benchmark]

I am not remiss that 1977 is so prevalent in rainedance's research.

[uncle W]

1967 was one of the coldest years in the ne and the winter of 67-68 was very cold. I doubt  we will se that this year. Probably milder and wetter with more snow than 67-68 in nyc…twt

[40/70 Benchmark]

3 hours ago, uncle W said:

1967 was one of the coldest years in the ne and the winter of 67-68 was very cold. I doubt  we will se that this year. Probably milder and wetter with more snow than 67-68 in nyc…twt

Works for me.

[George001]

The next couple of weeks will be very telling about what the enso state is going to look like for winter. I’ve seen predictions for anything from weak El Niño to strong La Niña on this board, but the general consensus seems to be weak La Niña . That is consistent with what the CFSv2 is forecasting so there is alot of merit to that idea. I’m leaning stronger right now but it is very possible I am putting too much weight onto the MEI and subsurface as has been mentioned. However, I do expect the chances of La Niña this winter to increase to over 80% in the next update from roughly 60-70% in the July update. If we do get severe North Atlantic blocking this winter, which is what the early signs I’m looking at right now indicate, as crazy as it sounds my analogs for moderate or stronger la ninas are more favorable than the weak Nina or cold neutral (both of which are still more favorable than an average winter, but not as much as my early thought strong and moderate Nina analogs). Even if it’s not quite strong, I do think the La Niña will influence our pattern in the winter more than expected due to the low mei values, as well as the La Niña peaking in the fall which makes it so by the time December comes we are already in a full blown La Niña pattern. When a La Niña develops late like 2017-2018 (weak La Niña), it didn’t really influence our pattern a whole lot until later in the winter. On the other hand a winter like 2010-2011, La Niña was strong and well coupled with the atmosphere, so it was the main driver that influenced our weather that year the entire early December- late March period. An important detail that I confused in my earlier posts is that how much the La Niña is influencing our weather pattern isn’t necessary related to the strength of the La Niña. Last year while the La Niña was on the stronger side at -1.3 oni, it wasn’t dominating the pattern due to the weaker mei values. There were times where the pattern was more La Niña like but NYC getting more snow than Boston is not Nina like at all. I do think we will see a more La Niña like pattern this year, what that will look like depends on the strength. A low end moderate nina with severe North Atlantic blocking can lead to extreme winters with 3-4 severe blizzards as well as many decent sized storms on top of it. It seems like in stronger la ninas December and January are more favorable where as February and March are less favorable. Idk what the exact stats are but it seems like February usually sucks in ninas regardless of strength, where as March is decent in weak ninas, bad in Moderate or strong. Based on what ive read Strong La Niña is the most favorable Enso state there is for December and it’s a really strong signal too, kinda like Feb being big in weak ninos like 2014-2015. 

[uncle W]

without blocking it doesn't matter what the enso is next winter...

[uncle W]

1 hour ago, uncle W said:

without blocking it doesn't matter what the enso is next winter...

la nina Dec with a neg ao...

[uncle W]

La nina dec without a neg ao...

[George001]

1 hour ago, uncle W said:

without blocking it doesn't matter what the enso is next winter...

In El Niño since there is limited northern stream interaction with an active southern branch dont you want less blocking because otherwise the storms go too far south and you get the blizzard of 2016, congrats mid Atlantic? Though that was really good in NYC and the coast of southern New England, more north areas got skunked due to the severe blocking. 2009-2010 also skunked areas north of NYC while NYC south got hammered with the strong nino+ severe North Atlantic blocking. Then in 2011 we had strong North Atlantic blocking again but a strong Nina instead and NYC north got hammered, my area got so much snow that year the weight of the snow on the roof it caused a leak with the paint dripping in. That happened only twice I can remember, the severe winters of 2010-2011 and 2014-2015. Do you by any chance have analogs of the severe North Atlantic blocking years for different enso states? I am curious to how that would impact the snow chances in southern New England.

 

edit- lmao you already posted em before I finished writing my post

[uncle W]

la nina dec with a neg nao...1975 and 1984 were o.o...

[uncle W]

la nina dec with a pos nao...

[uncle W]

28 minutes ago, George001 said:

In El Niño since there is limited northern stream interaction with an active southern branch dont you want less blocking because otherwise the storms go too far south and you get the blizzard of 2016, congrats mid Atlantic? Though that was really good in NYC and the coast of southern New England, more north areas got skunked due to the severe blocking. 2009-2010 also skunked areas north of NYC while NYC south got hammered with the strong nino+ severe North Atlantic blocking. Then in 2011 we had strong North Atlantic blocking again but a strong Nina instead and NYC north got hammered, my area got so much snow that year the weight of the snow on the roof it caused a leak with the paint dripping in. That happened only twice I can remember, the severe winters of 2010-2011 and 2014-2015. Do you by any chance have analogs of the severe North Atlantic blocking years for different enso states? I am curious to how that would impact the snow chances in southern New England.

 

edit- lmao you already posted em before I finished writing my post

NYC averages almost 9" of snow in Dec when the ao was neg for la nina...it averages less than 2" with a pos ao...

[raindancewx]

I'm more interested in the development and future decay of the event than the actual peak strength. The CFS and Canadian have different ideas with regard to structure. It's a shame the Jamstec isn't back yet.  That thing had a good read on SST configurations. I am not trying to setup some super cold La Nina winter when I list the years that have rare outcomes. It's just stuff I look at along the way to winter. 

To me the big issue with 1967 is simply how cold it gets in Nino 3 relative to the other zones. It's a weird setup in an ENSO sense. I do think a top-five cold December is possible with regard to the 1991-2020 period nationally. A lot of years in the 1960s like December 1960, December 1963 and December 1967 are actually much colder than that.

If you just went by current recency profiles in SSTs and US temps, something like 1967, 2011, 2013, 2017 is a decent start for winter. The hurricane season will provide more hints going forward.

I don't really worry about the QBO as an index much because it is auto-correlated to the 11-year solar cycle.

(~11 years x 12 months = 132 months. x 2 = 264 months)

Every ninth 28-29 month QBO cycle should "match" with every second solar cycle by timing:

264 months / 29 months = 9.1 QBO cycles, or "laps" if you think of it as a race to the same spot around a 'track' of what is possible.)

More generally, you tend to find good AMO/PDO sst matches at 60 year intervals +/-3 to adjust for ENSO differences I find. So I generally look at years that are 30, 60, 90 years prior (+/-3 per 30 year cycle) and then the years at 11-year intervals first. 

1967-->1978-->1989-->2000-->2011-->2022 is pretty close and certainly meets the criteria given that solar cycle length varies from 9-13 years since the SILSO observations started.

1960-->2020 is the 60 year match, and 1960 was also a very hot NW Summer, especially July 1960.

 

[40/70 Benchmark]

16 hours ago, George001 said:

The next couple of weeks will be very telling about what the enso state is going to look like for winter. I’ve seen predictions for anything from weak El Niño to strong La Niña on this board, but the general consensus seems to be weak La Niña . That is consistent with what the CFSv2 is forecasting so there is alot of merit to that idea. I’m leaning stronger right now but it is very possible I am putting too much weight onto the MEI and subsurface as has been mentioned. However, I do expect the chances of La Niña this winter to increase to over 80% in the next update from roughly 60-70% in the July update. If we do get severe North Atlantic blocking this winter, which is what the early signs I’m looking at right now indicate, as crazy as it sounds my analogs for moderate or stronger la ninas are more favorable than the weak Nina or cold neutral (both of which are still more favorable than an average winter, but not as much as my early thought strong and moderate Nina analogs). Even if it’s not quite strong, I do think the La Niña will influence our pattern in the winter more than expected due to the low mei values, as well as the La Niña peaking in the fall which makes it so by the time December comes we are already in a full blown La Niña pattern. When a La Niña develops late like 2017-2018 (weak La Niña), it didn’t really influence our pattern a whole lot until later in the winter. On the other hand a winter like 2010-2011, La Niña was strong and well coupled with the atmosphere, so it was the main driver that influenced our weather that year the entire early December- late March period. An important detail that I confused in my earlier posts is that how much the La Niña is influencing our weather pattern isn’t necessary related to the strength of the La Niña. Last year while the La Niña was on the stronger side at -1.3 oni, it wasn’t dominating the pattern due to the weaker mei values. There were times where the pattern was more La Niña like but NYC getting more snow than Boston is not Nina like at all. I do think we will see a more La Niña like pattern this year, what that will look like depends on the strength. A low end moderate nina with severe North Atlantic blocking can lead to extreme winters with 3-4 severe blizzards as well as many decent sized storms on top of it. It seems like in stronger la ninas December and January are more favorable where as February and March are less favorable. Idk what the exact stats are but it seems like February usually sucks in ninas regardless of strength, where as March is decent in weak ninas, bad in Moderate or strong. Based on what ive read Strong La Niña is the most favorable Enso state there is for December and it’s a really strong signal too, kinda like Feb being big in weak ninos like 2014-2015. 

I wouldn't say last season has a weak MEI....it was on par with a moderate event.