ENSO - El Nino & La Nina Discussions

[Hiramite]

The latest from the CPC regarding ENSO issued 2-14-22.  (A pdf.)

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwiW7Y7loYn2AhWbRzABHdN3CQcQFnoECAkQAQ&url=https%3A%2F%2Fwww.cpc.ncep.noaa.gov%2Fproducts%2Fanalysis_monitoring%2Flanina%2Fenso_evolution-status-fcsts-web.pdf&usg=AOvVaw3rCcwu_4T330uvE2KxcqE1

Edited February 18, 2022 by Hiramite

[ClicheVortex2014]

Zombie La Nina?

Shows really well:

1) Warm subsurface water in the eastern region is slowly making its way to the surface

2) An apparent westward push of the cold surface water in the aforementioned region

3) Significant subsurface cooling below the surface at around 160W... i.e., region 3.4. 

In the next few months, we should see Nino 1+2 warm pretty significantly while the western regions cool. Should become more central or west-based. That seems pretty certain at this point.

Less certain: If the subsurface at 160W continues cooling and then pushing east and up, then it seems pretty likely that we'll see La Nina last at least through Fall. 

[ClicheVortex2014]

Region 3.4 is now at the coolest it has been this winter.... -1.1C. Impressive resiliency. 

Week of March 2:

Region 1+2: -1.3C
Region 3: -1.2C
Region 3.4: -1.1C
Region 4: -0.6C

Peak of La Nina (week of December 15, 2021)

Region 1+2: -1.7C
Region 3: -1.2C
Region 3.4: -1.1C
Region 4: -1C

https://www.cpc.ncep.noaa.gov/data/indices/wksst9120.for

 

[so_whats_happening]

We don't necessarily have a climate or GW thread but this is an interesting take on a situation that may be developing as we pull into a a potential 3rd year la nina. The idea of more consistent La Nina years could make sense, less heat transport north would mean a warmer Atlantic (El nino in the Atlantic more often than not) signaling a need for the walker circulation to enhance. We would essentially now have two regions of lift from the warmer waters than just the maritime region of the pacific or potentially that region would weaken, lot of ifs associated with that idea. The walker circulation would be enhanced by more lift occuring in the Atlantic from the warmer waters setting up the climate into a more la nina like situation. It is an interesting take as we don't know for certain how the oceans and atmosphere will keep changing under a warming climate. 

I feel this could argue the case to get out of these more frequent la nina like states we would need to have potentially more intense el nino situations sea surface temp wise not necessarily atmospherically as we have seen through MEI data that even some of the most intense El ninos have had less atmospherical impacts on the globe even though SST anoms were at their highest ever recorded in the el nino back in 2016, 1983 sets the precedent of truly intense El Nino states. Warming oceans may help these events peak in anomalies but have less impactful weather globally of an el nino?

Would love to hear some thoughts on this idea or any other thoughts on the subject.

Here are the two articles one is paid unfortunately... these were originally posted in AmericanWx but just hate having discussions over there.

https://phys.org/news/2022-06-huge-atlantic-ocean-current-downif.html

https://www.nature.com/articles/s41558-022-01380-y

[StLweatherjunkie]

On 6/11/2022 at 4:38 AM, so_whats_happening said:

We don't necessarily have a climate or GW thread but this is an interesting take on a situation that may be developing as we pull into a a potential 3rd year la nina. The idea of more consistent La Nina years could make sense, less heat transport north would mean a warmer Atlantic (El nino in the Atlantic more often than not) signaling a need for the walker circulation to enhance. We would essentially now have two regions of lift from the warmer waters than just the maritime region of the pacific or potentially that region would weaken, lot of ifs associated with that idea. The walker circulation would be enhanced by more lift occuring in the Atlantic from the warmer waters setting up the climate into a more la nina like situation. It is an interesting take as we don't know for certain how the oceans and atmosphere will keep changing under a warming climate. 

I feel this could argue the case to get out of these more frequent la nina like states we would need to have potentially more intense el nino situations sea surface temp wise not necessarily atmospherically as we have seen through MEI data that even some of the most intense El ninos have had less atmospherical impacts on the globe even though SST anoms were at their highest ever recorded in the el nino back in 2016, 1983 sets the precedent of truly intense El Nino states. Warming oceans may help these events peak in anomalies but have less impactful weather globally of an el nino?

Would love to hear some thoughts on this idea or any other thoughts on the subject.

Here are the two articles one is paid unfortunately... these were originally posted in AmericanWx but just hate having discussions over there.

https://phys.org/news/2022-06-huge-atlantic-ocean-current-downif.html

https://www.nature.com/articles/s41558-022-01380-y

Speculating about changes to a zonal Pacific circulation (ENSO) based on a weakening meridional Atlantic circulation (AMOC) is just that, speculation. If Atlantic ENSO become more amplified with time then I'd expect the effects to primarily be downstream across Eurasia. However, I don't think we haven't observed either circulation for a sufficiently long period of time to know whether the observed changes are decadal variability or a trend associated with climate change. 

It's important to remember that La Nina is enhanced trade winds and El Nino is a trade wind reversal. In other words, La Nina is the background state of the circulation. The apparent trend in MEI values is interesting and worthy of further investigation, but I'd caution against statements like this: "the most intense El ninos have had less atmospheric impacts." MEI is based on a fixed mathematic method for quantifying ENSO based on MSLP, SST, surface winds, and outgoing longwave radiation,  but ENSO is dynamic so a fixed method to determine the 'atmospheric impacts' is likely flawed.

MEI relies on EOF analysis, but two factors inhibit physical interpretation of EOFs: (1) the orthogonality constraint and (2) the derived patterns may be domain dependent.  Physical systems are not necessarily orthogonal and if the patterns depend on the region used they may not exist if the the domain changes.

El Nino and La Nina are approximately opposite, but some asymmetry exists so the orthogonal assumption is flawed. Further, there's a diverse range of ENSO phenomena (east vs west-based) suggesting domain dependence of the EOF analysis that isn't accounted for in MEI analysis. All that's to say, I wouldn't read too much into proposed climate-change induced trends of inter-annual to decadal modes of climate variability. 

I will however say that a third La Nina winter seems incredibly unlikely where I'm sitting. I've been thinking cool neutral for a while now, which is supported by 15 of the last 18 years being either El Nino or La Nina ... ENSO needs a breather. 

 

[so_whats_happening]

On 7/3/2022 at 1:22 PM, StLweatherjunkie said:

Speculating about changes to a zonal Pacific circulation (ENSO) based on a weakening meridional Atlantic circulation (AMOC) is just that, speculation. If Atlantic ENSO become more amplified with time then I'd expect the effects to primarily be downstream across Eurasia. However, I don't think we haven't observed either circulation for a sufficiently long period of time to know whether the observed changes are decadal variability or a trend associated with climate change. 

It's important to remember that La Nina is enhanced trade winds and El Nino is a trade wind reversal. In other words, La Nina is the background state of the circulation. The apparent trend in MEI values is interesting and worthy of further investigation, but I'd caution against statements like this: "the most intense El ninos have had less atmospheric impacts." MEI is based on a fixed mathematic method for quantifying ENSO based on MSLP, SST, surface winds, and outgoing longwave radiation,  but ENSO is dynamic so a fixed method to determine the 'atmospheric impacts' is likely flawed.

MEI relies on EOF analysis, but two factors inhibit physical interpretation of EOFs: (1) the orthogonality constraint and (2) the derived patterns may be domain dependent.  Physical systems are not necessarily orthogonal and if the patterns depend on the region used they may not exist if the the domain changes.

El Nino and La Nina are approximately opposite, but some asymmetry exists so the orthogonal assumption is flawed. Further, there's a diverse range of ENSO phenomena (east vs west-based) suggesting domain dependence of the EOF analysis that isn't accounted for in MEI analysis. All that's to say, I wouldn't read too much into proposed climate-change induced trends of inter-annual to decadal modes of climate variability. 

I will however say that a third La Nina winter seems incredibly unlikely where I'm sitting. I've been thinking cool neutral for a while now, which is supported by 15 of the last 18 years being either El Nino or La Nina ... ENSO needs a breather. 

 

Oh hey nice to see you. Yea as many things go with climate it is always a bit of speculation. We definitely do need more data of such occurrences to better understand these processes. Im curious though what implications would be seen in Eurasia from a more prominent El Nino Atlantic? I would assume greenification of horse latitudes and expanded drought situations of mid latitudes as the azores high may be pushed further north allow troughing to take hold more often further south thus reducing trade wind effects? I wonder how this would affect hurricane season too.

 

I completely understand MEI data can be a flawed metric. I feel this is the closest we have to fully encapsulating the idea of ENSO without looking at things individually ( MSLP, SST, OLR, and surface winds).

The fact that we have not seen a drop in SOI values, continuation of SST cool pool in nino 4 and no real change up in OLR location (looking like just a reload at this point) I would argue this shows quite the potential of a La Nina for this winter. The only fly in the ointment would be the subsurface look we currently have.

The 2020/21 season (1st year for the La Nina) saw some of the coldest temps at the surface with subsurface rather decent as well. That year we saw a legit moderate La Nina but atmospherically it seemed it was almost anything but MEI data also agrees with this as even though moderate status, via ONI data, was achieved we didn't get hit hard by a La Nina atmosphere that winter ended up rather close to even slightly above average snowfall with rather neutral temps throughout winter (colder second half) although it seemed to be from one storm that hit in February where most locations in the east got half to most of their seasonal total (arguments can be made if it wasn't for this La Nina would have rained supreme) . High latitude blocking was our friend that year but didn't really help until the second half of winter. Spring didnt transition into the normal warmer in the east mode as high latitude blocking waned we had a warmer north cooler south situation going into summer which seemed to continue even into summer; sounds very El Nino like to me on that front.

The 2021/22 season started out extremely warm across much of the country for December, more typical of an El nino like pattern but subsurface Pacific temps were some of the coldest we have seen in a fairly long time. Yet only made it to barely scraping moderate status, would argue it was more of a weak La Nina than anything but the atmosphere seemed to readjust itself and soon enough we had more of a La Nina pattern show up. Turned rather cold rather quick going into January and would ease off by about early March seemingly fairly typical of a La Nina upper midwest was cold to say the least. We had the warmth in spring which usually follows a La Nina so we could also see that this year has overall acted more like a La Nina state than the previous even with a weaker La Nina. MEI data also shows this.

I can see one area where this MEI data could potentially be a flawed in the last triple dip Nina back at the turn of the millennia MEI was rather weak even though we had almost 2 solid years of moderate to strong Nina SST anoms.  I can't explain how in some instances we have some rather intense atmospheric conditions in a rather average La Nina versus years with intense cooling but low atmospheric La Nina conditions. There could be something there that 1st year La Ninas seemingly regardless of strength tend to be average winters for most locations while second takes on a full La Nina atmosphere bringing with it cold initially and warm spring with low snowfall, and with third year being the most random potential since it doesn't occur very often. 

Typical La Nina conditions around here are winters tend to be front loaded for us with warming as the season goes on into a warm spring and then hot/dry summer. 

Of recent years la ninas DJF into MAM:

-Triple dip 1973-1976

below average snowfall except second year was closer to average (warm winter/spring 1st year and 2nd year,  3rd year average winter warm spring)

-1998/99 below average snow/ average to slightly above average winter, average spring (1st year)

-1999/2000 average snow/ average temps for both seasons (warm plains)

-2000/01slightly above average snow/ cold DJF and MAM (high latitude blocking) 3rd year

-2005/06 slightly below average snowfall/ warm north cool south (high latitude blocking)

-2007/08 below average snow/ average winter temps, cold spring (some HLB in spring) 1st year

-2008/09 below average snow/ cold winter average spring ( ridge was present in spring but displaced further north allowing more moisture than heat scenario) 2nd year

-2010/11 above average snow/ cold winter warm spring (1st year) 

-2011/12 well below average snow/ warm winter, warm spring (year of MORCH) 2nd year

-2016/17 below average snow/ warm winter, warm spring (1st year)

-2017/18 above average snow/ average winter, cold spring (2nd year)

-2020/21 above average snow/ average winter, warmish spring (mainly northern tier of the country was warm, NE, HLB year) 1st year

-2021/22 well below average snow/ average winter (cold plains) warm spring (2nd year)

Definitely seems like a lag situation taking place where before we use to see La Nina coupled fairly well in 1st year and then decouple in the 2nd year where as now we see 1st year tends to not so much be a La Nina base state atmospherically and 2nd year comes around to a more pronounced atmospheric mode. Of course more data will be needed so I guess at this point we continue to watch and see how things unfold.

The biggest take away honestly may be where the coolest portion of the tropical pacific was set up during those years (east based, central, or west based or all three regions). Intensity of the cold anoms may be a factor in enhancing these regions and the subsequent atmospheric conditions during those years. In order to get a better picture of that though it would require more digging of data. Time I don't have right now unfortunately.

Edited July 8, 2022 by so_whats_happening

[so_whats_happening]

Mind you this is the first time we have seen temps actually cool more in the spring rather than the typical warming of SSTs we see after a La nina winter since 1975, winter of 1975/76 featured a strong la nina following a weak la nina the winter before.

Kind of wish we had more data before 1979 for surface and subsurface SSTs but we gotta deal with what we have.

Edited July 8, 2022 by so_whats_happening

[MaineJay]

Don't have much to add here right now. But just posting the NMME.  I'm not 100% sure, but it looks like some of these models have been upgraded/swapped/added 

The "raw" plumes are a bit colder.

[so_whats_happening]

It looks like we are reloading

[MaineJay]

On 7/10/2022 at 10:57 AM, MaineJay said:

Don't have much to add here right now. But just posting the NMME.  I'm not 100% sure, but it looks like some of these models have been upgraded/swapped/added 

The "raw" plumes are a bit colder.

August initial conditions NMME 

Unscaled

 

[StLweatherjunkie]

In my opinion, a 'triple-dip' La Nina is still questionable. Probably the most important aspect of the recent period of cooling is how it's misaligned with ENSO climatology. The recent cooling also doesn't compare to last fall:

Also, the Euro shows a couple lows on the south side of the equator next week. Since lows spin clockwise down there, these have potential to be WWBs.

I'll close out by saying all available model guidance agrees that Nino 3.4 will warm over time, but it's unclear when. History indicates that most La Nina's move to neutral for around a year before transitioning to El Nino. IMHO that seems like the way to go this year too, because this one seems to be sputtering. 

[so_whats_happening]

On 8/14/2022 at 5:24 PM, StLweatherjunkie said:

In my opinion, a 'triple-dip' La Nina is still questionable. Probably the most important aspect of the recent period of cooling is how it's misaligned with ENSO climatology. The recent cooling also doesn't compare to last fall:

Also, the Euro shows a couple lows on the south side of the equator next week. Since lows spin clockwise down there, these have potential to be WWBs.

I'll close out by saying all available model guidance agrees that Nino 3.4 will warm over time, but it's unclear when. History indicates that most La Nina's move to neutral for around a year before transitioning to El Nino. IMHO that seems like the way to go this year too, because this one seems to be sputtering. 

For now lets see if we can get a WWB to actually get going. Not seeing much in the way of 850mb u winds relaxing too much. GFS does have blip 1-2 days where we do reverse it. I more so would like to see the deeper reds pop up on this chart to know for certain that is coming. Plus I'm not so sure a westward propagating wind situation will result in all too much. As for comparing this years subsurface to last year we really didn't start tanking the subsurface until mid September so far we are on par with what has occurred even to last year. Unfortunately did not save the u wind anoms last year or the year before. Wish they would have an archive of this stuff.

 

As expected Nino 4 and 3.4 (namely 4) should be the coolest as we move forward and 3, 1+2 regions should be quite variable this season. There is a lot of heat in the Maritime region so it is bound to be released at some point. I would say we may need to wait until we see how things progress into September before go full on this is a dud La Nina year.

 

[so_whats_happening]

Just now, so_whats_happening said:

For now lets see if we can get a WWB to actually get going. Not seeing much in the way of 850mb u winds relaxing too much. GFS does have blip 1-2 days where we do reverse it. I more so would like to see the deeper reds pop up on this chart to know for certain that is coming. Plus I'm not so sure a westward propagating wind situation will result in all too much. As for comparing this years subsurface to last year we really didn't start tanking the subsurface until mid September so far we are on par with what has occurred even to last year. Unfortunately did not save the u wind anoms last year or the year before. Wish they would have an archive of this stuff.

 

As expected Nino 4 and 3.4 (namely 4) should be the coolest as we move forward and 3, 1+2 regions should be quite variable this season. There is a lot of heat in the Maritime region so it is bound to be released at some point. I would say we may need to wait until we see how things progress into September before go full on this is a dud La Nina year.

 

BTW new ENSO numbers were out for MJJ and it decreased slightly to -0.9 this is the true fashion of what should have happened since April (ever decreasing and then the turnaround happens this month into September. Our two 3rd year La Ninas both acted differently from this one 1975 featured continued cooling through summer going into a strong La Nina. While 2000 went from strong La Nina to weak through much of the winter. Guess this round may produce a different flavor if you will.

[so_whats_happening]

On 8/16/2022 at 2:26 AM, so_whats_happening said:

For now lets see if we can get a WWB to actually get going. Not seeing much in the way of 850mb u winds relaxing too much. GFS does have blip 1-2 days where we do reverse it. I more so would like to see the deeper reds pop up on this chart to know for certain that is coming. Plus I'm not so sure a westward propagating wind situation will result in all too much. As for comparing this years subsurface to last year we really didn't start tanking the subsurface until mid September so far we are on par with what has occurred even to last year. Unfortunately did not save the u wind anoms last year or the year before. Wish they would have an archive of this stuff.

 

As expected Nino 4 and 3.4 (namely 4) should be the coolest as we move forward and 3, 1+2 regions should be quite variable this season. There is a lot of heat in the Maritime region so it is bound to be released at some point. I would say we may need to wait until we see how things progress into September before go full on this is a dud La Nina year.

 

Not a bad forecast. Looks like actual was a little less intense than the actual occurrence. We may have another round of decent easterlies setting up.

[Iceresistance]

Bumping this because the Nino 1+2 is now at +1.1°C, we need an active ENSO region updates!

https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf

[so_whats_happening]

Nino 1+2 tends to have a lot of noise associated with it and changes rather drastically so we can't know for sure a full on El Nino will take hold yet. We unfortunately will have to wait and see how things evolve over the next 2 months as we move through the spring barrier. What looks to come about though is a warm neutral state or even weak El Nino as we go into fall and winter. The atmosphere is still very much La Nina like so this will take some time to see if we can connect the two in any way or whether we have an oceanic component reading one signal while the atmosphere reading another. I would say look to maybe May area and we should have a better grasp on the potential to come. Of the about 3 episodes where we came out of a near 3rd year La Nina to a full 3rd year La Nina (1954-56 fell short while having 1973-76 and 1998-2001 in our back pockets for a 3rd year La Nina). We have a decent signal of at least a weak El Nino to potentially low end moderate event based off past data. Otherwise take your bets by throwing a dart at the board.

Would be rather unprecedented to go into anywhere near a 4th year La Nina so we can probably effectively take that off the table.

[Iceresistance]

Very strong MJO Phase 8, could we have a Super El Nino?

Joe Bastardi said that the only other good analog years that featured that was 1997 and 2015, both were Super El Nino years.

[MaineJay]

6 hours ago, Iceresistance said:

Very strong MJO Phase 8, could we have a Super El Nino?

Joe Bastardi said that the only other good analog years that featured that was 1997 and 2015, both were Super El Nino years.

Another warm east coast winter and folks will lose any marbles they have remaining.

NMME plumes

Unscaled

 

[Iceresistance]

Just now, MaineJay said:

Another warm east coast winter and folks will lose any marbles they have remaining.

NMME plumes

Unscaled

 

The 2015 Super El Nino featured insane winter in the East Coast. Boston got over 100 inches of snow that winter.

[MaineJay]

2 minutes ago, Iceresistance said:

The 2015 Super El Nino featured insane winter in the East Coast. Boston got over 100 inches of snow that winter.

2015-16 was the super Niño winter.  Outside the big mid Atlantic storm, it was a warm stinker.  One of the worst ever up here.

You are thinking of the preceding 2014-15 winter I believe, I think it was weak Niño, or borderline.

[Iceresistance]

Just now, MaineJay said:

2015-16 was the super Niño winter.  Outside the big mid Atlantic storm, it was a warm stinker.  One of the worst ever up here.

You are thinking of the preceding 2014-15 winter I believe.

Whoops, that was the 2014-2015 winter indeed.

Even the nasty Winter that was projected here was also a dud! (And combine that with Christmas Tornadoes!)

[MaineJay]

1 minute ago, Iceresistance said:

Whoops, that was the 2014-2015 winter indeed.

Even the nasty Winter that was projected here was also a dud! (And combine that with Christmas Tornadoes!)

   You could make the argument though, that if a double dip Niño occurred, with the second being exceptionally strong, that 2014-15 *could* be considered an analog. 

    But forecasting ENSO 9 months in advance is hard enough, let alone 21 months.

[Iceresistance]

2 minutes ago, MaineJay said:

   You could make the argument though, that if a double dip Niño occurred, with the second being exceptionally strong, that 2014-15 *could* be considered an analog. 

    But forecasting ENSO 9 months in advance is hard enough, let alone 21 months.

Yeah, but at least the La Nina is gone. 

[so_whats_happening]

6 hours ago, Iceresistance said:

Very strong MJO Phase 8, could we have a Super El Nino?

Joe Bastardi said that the only other good analog years that featured that was 1997 and 2015, both were Super El Nino years.

2 years doesn't give me a lot of confidence that a super Nino is right around the corner. Normally after a triple dip there is a lag/ hangover situation where atmosphere doesn't catch up to oceanic.

BTW the two examples had very different subsurface structures than compared to this year around this time. I would have to dive in year after year to get a better idea where we land and I just don't have the time right now unfortunately. Here is the site though. https://ds.data.jma.go.jp/gmd/tcc/tcc/products/elnino/ocean/t-eq_tcc.html

Also we would need a sustained MJO wave as well and not for it to nose dive again to null.

[Iceresistance]

1 minute ago, so_whats_happening said:

2 years doesn't give me a lot of confidence that a super Nino is right around the corner. Normally after a triple dip there is a lag/ hangover situation where atmosphere doesn't catch up to oceanic.

BTW the two examples had very different subsurface structures than compared to this year around this time. I would have to dive in year after year to get a better idea where we land and I just don't have the time right now unfortunately. Here is the site though. https://ds.data.jma.go.jp/gmd/tcc/tcc/products/elnino/ocean/t-eq_tcc.html

Also we would need a sustained MJO wave as well and not for it to nose dive again to null.

I suppose you are right for this one, it seems like that the atmosphere got very used to the La Nina conditions. 

 

WIth the MJO very strong over the WPAC, we could see a powerful WWB that will drive the La Nina remnants into history!