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2021-2022 ENSO


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The CFS may be off it's rocker, but it has a very wet October in the Southwest. We're heading into a cold-ENSO winter. But we also should have a pretty high ACE value. It's not real common for a wet October + big ACE combo to happen down here, especially with a cold ENSO look. I'm real curious to see what happens in the Atlantic - 2020 October-November ACE was third highest since 1931, behind 1932 and 2016. Unheard of to be as active as 2020 was late two years in a row. So ACE might only hit 155 or 160 or something. My weighted analogs of 1974 and 2017 as a blend might actually be about right - 150 ish ACE, with 1.00 inch of rain in October. 

Some of the moisture shown is the CFS not understanding a lot of the incoming rain will fall 9/30 in actual American time and not UTC. But it probably does see an actual wet month even ignoring that issue.

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1 hour ago, raindancewx said:

The CFS may be off it's rocker, but it has a very wet October in the Southwest. We're heading into a cold-ENSO winter. But we also should have a pretty high ACE value. It's not real common for a wet October + big ACE combo to happen down here, especially with a cold ENSO look. I'm real curious to see what happens in the Atlantic - 2020 October-November ACE was third highest since 1931, behind 1932 and 2016. Unheard of to be as active as 2020 was late two years in a row. So ACE might only hit 155 or 160 or something. My weighted analogs of 1974 and 2017 as a blend might actually be about right - 150 ish ACE, with 1.00 inch of rain in October. 

Some of the moisture shown is the CFS not understanding a lot of the incoming rain will fall 9/30 in actual American time and not UTC. But it probably does see an actual wet month even ignoring that issue.

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Now tell me this...what does ACE do to the weather patterns and such?

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The higher the ACE the more likely it is the entire West has heat and dryness in a La Nina. Not just part of the west seeing one or the other, or just the Southwest - the whole West.

It becomes close to a guarantee somewhere between 160-200 ACE I find. Last year was 180, and most of the west (TX, NM, CO, WY excluded where it was fairly average to cold for temps, and varied for precip) was pretty warm and dry. There is ACE inflation though via measuring techniques, so I treat last year like a 165-170 year. The highest ACE La Ninas all feature 3-6 month periods with literally no rain or snow in places in the Southwest - extraordinary dryness even here.

I've also mentioned that in NYC/Philly/Baltimore the La Ninas with over 150 ACE are close to a coin flip for a good snow year (+20% or more) while all other La Ninas have close to 0% odds of a snowy winter. Look at your high ACE years for snow in the NE with La Ninas: 1933-34, 1995-96, 2010-11, 2017-18, 2020-21 are all in there as examples.

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The PMM warming this month makes me think the cold will have much more trouble getting into Nino 4 than last year. A lot of the cold-ENSO winters in the 1959-1967 period are pretty cold around 120W at the equator and then very warm in the North Pacific. Those years are pretty interesting winters, also a lot of nasty Gulf Hurricanes and similar features. The hurricane season put up 75 ACE 10/1-11/30 last year (3rd highest since 1931). Don't really see us getting particularly close to that in 2021. After Sam finally dies, could be quiet for a bit. Very unlikely to get a four/five combo in November two years in a row.  

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For reference, these are the biggest October & Novembers for ACE: 

87.8 (October 1878)

71.0 (November 1932)

Highest Oct-Nov ACE since 1850 is 95 in 1878.

The last ten La Ninas (2020, 2017, 2016, 2011, 2010, 2008, 2007, 2005, 2000, 1999) average only 35 ACE (+a bit more December). The 30-year average is 22 for 1981-2010. I kind of look at 145 as a good guess for now. 110 through 9/30 and then 35 more? The pattern should shift to somewhat west of what it was last year for cold dumps if the ACE drops from ~180 to ~145 going into winter.

https://psl.noaa.gov/gcos_wgsp/Timeseries/Hurricane/hurr.atl.ace.data

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Final SOI matches to July-September are in (broad) agreement with the CFS for October.

SOI     July    Aug    Sept
1938    17.2  12.4    7.6
1974     11.1    6.3    12.2
1981      8.1    5.1     6.4
1996     6.6    4.8    6.9
1998    12.8   9.7    12.1
2011      9.1    2.6    11.1
Blend    10.8   6.8   9.4
2021    16.3    4.4    9.2

A blend of 1938, 1974, 2011 is basically an ideal/canonical +WPO look for October. Matches fairly well to September for an analog based on three numbers and nothing else.

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Don't think the new Canadian has the right strength (too cold) for the La Nina, but it does have a real -PDO look. Way more than the last run did. 

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The new temperature outlook for October is pretty close to the winter analogs I have with a +WPO - I did add one degree because the average time is 1988.

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La Nina is really getting going

https://www.pmel.noaa.gov/tao/drupal/assorted_plots/images/TAO_5Day_EQ_xz.gi(f)

It will keep strengthening on the surface probabably. 

There has never been a -PNA October during La Nina! The greatest was +120dm in 2007 and 2008, we had the strongest two, but I think both had a stronger EPO. Since satilte data in 1948- 1955, 1975, 1985, 6 years were strong +PNA/La Nina. Last year, 2020 was +PNA/La Nina. 

Models through mid-October have about a +200dm -PNA, and we have never really done that before for the month of October in La nina since 1948. It will be interesting to see if we beat the 2007/8 record of +120dm for themonth. (last year was +PNA October-LaNina)

8b.jpg

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The subsurface for 100-180W at the equator, 0-300m fell to -1.27 in September. That's colder than I expected. The simplest recent match that looks like the Canadian outlook is 2007, 2010, 2011, 2011 for July-Sept subsurface readings.

(year, july, aug, sept)

2011    +0.06  -0.54   -1.01

2011     +0.06  -0.54   -1.01

2010    -1.36   -1.74    -1.93

2007    -0.48   -0.68   -1.03

Avg     -0.43    -0.88    -1.25

2021    -0.40  -0.83   -1.27

 

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The correlation for 1979-2020 September subsurface readings and winter SSTs in Nino 3.4 is very strong. Near 0.8 for r-squared. But it is still highly variable. When I ran it using the -1.27 figure, I got 25.54C as the winter estimate. But...the errors historically imply it's 25.54C, +/-0.75C at 90% confidence in practice. In other words, running "warm" of the 25.54C is probably feasible. Last year's actual winter reading ran "cool" of the 25.80C the September subsurface projected as an example. The average error from plotting September subsurface v. Nino 3.4 at the surface in winter is plus or minus 0.4C.

Solar activity was over 51 sunspots for September - highest monthly since March 2016.

So far, we're off to a devastating start for snow.

 

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No real change at the surface from August-September. The subsurface in 2011 is an excellent match to 2021 for January-September. So it's likely the subsurface will stop cooling and flip to warming in October or early November, like 2011.  This is the subsurface (100-180W, 0-300m down) comparison.

              Jan      Feb    Mar      Apr      May    Jun      Jul      Aug      Sept
2011    -1.27    -0.22    0.50    0.58    0.47    0.39    0.06    -0.54    -1.01
2021    -1.02    -0.83    0.27    0.60    0.65    0.31    -0.40   -0.83    -1.27

October 2011 dropped to -1.26 in October, then reversed in November. It cooled again briefly in Dec-Jan, but October was the peak.

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20 hours ago, raindancewx said:

The subsurface for 100-180W at the equator, 0-300m fell to -1.27 in September. That's colder than I expected. The simplest recent match that looks like the Canadian outlook is 2007, 2010, 2011, 2011 for July-Sept subsurface readings.

(year, july, aug, sept)

2011    +0.06  -0.54   -1.01

2011     +0.06  -0.54   -1.01

2010    -1.36   -1.74    -1.93

2007    -0.48   -0.68   -1.03

Avg     -0.43    -0.88    -1.25

2021    -0.40  -0.83   -1.27

 

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The correlation for 1979-2020 September subsurface readings and winter SSTs in Nino 3.4 is very strong. Near 0.8 for r-squared. But it is still highly variable. When I ran it using the -1.27 figure, I got 25.54C as the winter estimate. But...the errors historically imply it's 25.54C, +/-0.75C at 90% confidence in practice. In other words, running "warm" of the 25.54C is probably. Last year's actual winter reading rain "cool" of the 25.80C the September subsurface projected as an example. The average error from plotting September subsurface v. Nino 3.4 at the surface is plus or minus 0.4C.

Solar activity was over 51 sunspots for September - highest monthly since March 2016.

So far, we're off to a devastating start for snow.

 

 The 9/21 OHC of -1.28 is the coldest for any month since 12/10 and it appears to be cooling more. Back to 1979, the only cooler Septs were in 2010, 1998, and 1983. When also considering the strongly +SOI of late Sep along with general +SOI trends, I still see no reason to back away from a moderate La Nina peak this fall/winter.

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1983 is an example of a year that under-performed the subsurface though at the surface.

26.0C in Nino 3.4 in DJF 1983-84. Despite a -2.25 subsurface reading in October. A lot of that is washing away the 1982-83 El Nino heat.

But you have a similar thing now - the heat from the March-June warm up below the surface has to get washed out. The La Nina last year was also weaker than 2010-11. So even though the subsurface is tracking like a colder 2011-12 event, the surface is tracking like a warmer 2011-12.

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As of today, we are already at 128 ACE, above the climo average of 105 ACE. This hurricane season has been severe, and in my opinion is likely to continue. On average, we gain 20 ACE from now until the end of hurricane season, however we currently have Hurricane Sam still going strong, and based on what I have seen from the navy and european guidance, the pattern remains good for more hurricanes. Therefore, in my opinion the ACE will likely increase at a rate well above climo, and will likely end around or even above 200. This has a major impact on the winter outlook.

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2 hours ago, raindancewx said:

1983 is an example of a year that under-performed the subsurface though at the surface.

26.0C in Nino 3.4 in DJF 1983-84. Despite a -2.25 subsurface reading in October. A lot of that is washing away the 1982-83 El Nino heat.

But you have a similar thing now - the heat from the March-June warm up below the surface has to get washed out. The La Nina last year was also weaker than 2010-11. So even though the subsurface is tracking like a colder 2011-12 event, the surface is tracking like a warmer 2011-12.

Yes...its going to be pretty close to the border of weak and mod.

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For 1950-2020, there is no winter in Nino 3.4 more than 1.0C colder than September. Not one. Fall can be pretty cold in that zone like last year. But Nino 3.4 is going to be warmer at the surface in September than last year when the monthly data is in.

It's probably around 26.20-26.40C on the monthly data for September. The amounts are not trivially small or localized warming either at the surface -

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As far as ACE goes, post Sam, I'm expecting another 20 to 40 more ACE by the end of the season. Sam is going to be the last gunslinger for a little bit. We have maybe 45 days left before the potential in the Atlantic ends. Each day without a storm lowers the ceiling on the season fast. Also, since 1850, ACE has topped 70 like three times in Oct-Nov. So 200 is a real stretch for me. It took a cat 4 and cat 5 in November just to hit 180 last year. In 2017, for comparison, we had 175 ACE in September alone.

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2 hours ago, raindancewx said:

For 1950-2020, there is no winter in Nino 3.4 more than 1.0C colder than September. Not one. Fall can be pretty cold in that zone like last year. But Nino 3.4 is going to be warmer at the surface in September than last year when the monthly data is in.

It's probably around 26.20-26.40C on the monthly data for September. The amounts are not trivially small or localized warming either at the surface -

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As far as ACE goes, post Sam, I'm expecting another 20 to 40 more ACE by the end of the season. Sam is going to be the last gunslinger for a little bit. We have maybe 45 days left before the potential in the Atlantic ends. Each day without a storm lowers the ceiling on the season fast. Also, since 1850, ACE has topped 70 like three times in Oct-Nov. So 200 is a real stretch for me. It took a cat 4 and cat 5 in November just to hit 180 last year. In 2017, for comparison, we had 175 ACE in September alone.

I’m going all in with the navy on this one, so I’m leaning towards 50+ ACE. The strength of the La Niña is increasing, which combined with the pattern on the models is making me very bullish on the back end of this hurricane season. At 128 already, with Sam possibly taking us to 140 or so even if we have an average La Niña rest of hurricane season (30 or so ace after Sam), that would put us at 170 and that’s ignoring the Navy. If the Navy is right we could see 220+.

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I'm still pretty happy with the blend I have for winter at the moment. You can see in the 5N-5S, 120W-170W area which is Nino 3.4, it's very close. It's a pretty strong match on the La Nina. There are other issues, but the IOD and AMO should move toward that blend of years with time. It's pretty hard to get a good match on the Nino zones at the surface for September. None of the individual years are great matches. 1959, 1985, 2000, 2001 are decent, but they have pretty big issues.

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Also have a backup blend for high solar activity. But not sure I'll need it yet. 

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Nino 3.4 came in at 26.21C. That's +0.32C from last year. Nino 4 is very similar to last year for September.

To be honest, Nino 3 is actually the most interesting - the cold water below the surface is there. But at the surface, it is running warmer than years I don't even consider La Ninas winters like 1959, 1961, 1962, 1966, 1967, 1978, 1985, 1996, 2001.

Nino 1.2/3 are both over 0.5C warmer than last year in September.

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                Nino1+2      Nino3        Nino34        Nino4
 Week          SST SSTA     SST SSTA     SST SSTA     SST SSTA
 01SEP2021     20.3-0.2     24.7-0.3     26.5-0.3     28.4-0.3
 08SEP2021     20.7 0.2     24.6-0.3     26.4-0.4     28.5-0.3
 15SEP2021     20.6 0.2     24.3-0.6     26.3-0.4     28.4-0.4
 22SEP2021     20.6 0.2     24.5-0.4     26.4-0.3     28.2-0.5
 29SEP2021     20.5-0.0     25.1 0.3     26.8 0.0     28.2-0.6

With Nino 3 warming a lot the past few weeks I would bite on the current week as a Modoki La Nina look. But I also don't think the month will finish anything like this. In any case, still running much warmer than last year. The 40 or so years since 1950 with cooling in Nino 3.4 from September to Dec-Feb average about ~0.35C of cooling, with 80% of the cooling years seeing a 0.05C to 0.65C drop from Sept to DJF.

 02SEP2020     18.9-1.7     23.6-1.4     25.8-0.9     28.4-0.4
 09SEP2020     19.5-1.0     23.4-1.4     25.7-1.0     28.5-0.3
 16SEP2020     20.0-0.4     23.6-1.3     25.9-0.8     28.2-0.5
 23SEP2020     19.6-0.8     23.6-1.2     25.7-1.0     28.1-0.6
 30SEP2020     20.1-0.4     23.8-1.1     25.6-1.1     27.9-0.8

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Year to date for subsurface, 2011 is objectively the best subsurface match - I suspect pre-1979 years match better, but the data doesn't go back that far. You can see in the Ja-Sp (Jan-Sept) column that the total difference between 2011 and 2021 is about ~0.26/month (2.37 divided by 9 months), and it's double that all other years, even 2017 in second place.

Year to date at the surface, Nino 3.4 and 4 are still remarkably close each month to a blend of 1967, 2001, 2011. Nino 3 is actually very close overall too, but September was much warmer than that blend.

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I have noticed that structure....ie east vs west(modoki) isn't as important in weak events,  as there is much more variance due to other exogenous factors......2000-2001 for instance was about as modoki as they come, but you never would have known it in terms of sensible weather....2008-2009 was also modoki and was pretty cold. Then again, 2005-2006 was very east based and yet pretty mild.

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