2024-2025 La Nina

[Stormchaserchuck1]

Yeah, here is the 76-year correlation between Solar Flux and the Winter NAO.. Nov-Feb being the strongest correlation:

Here's the 76-year regression average:

SLP

 

 

Nov-May:

all-year

[Stormchaserchuck1]

Since 1979, +QBO/La Nina minus -QBO/El Nino:

10mb

500mb

US surface air

[raindancewx]

If Hurricane Beryl hits Central America, South TX or Eastern Mexico next week, I think we're set up here for a pretty active monsoon in July. The colder La Nina winters out here tend to be very hot and dry all Summer. Hot / Wet Summers tend to be mostly warm with brief severe cold waves, that still average out pretty warm.

We've had rain already almost every day for ten days. It's been quite active. The whole city is actually flooding right now with close to an inch of rain in 30 minutes. The heat is actually quite fragile out here. The 97 at 3:30 is 63 now.

Atlantic ACE is still running below normal as of this afternoon. But it should catch up to normal and then jump above it over the next few days. MJO hasn't been particularly active in a while. I think it has to emerge and stay in four at high amplitude at some point over the next few months for the hurricane season to be hyperactive. May happen, but not sure yet.

[Stormchaserchuck1]

May-Sept SST correlation with following Dec-Mar NAO (strong)  (shown below is +NAO correlation. -NAO would be opposite). 

Current SSTs

[GaWx]

3 hours ago, Stormchaserchuck1 said:

Yeah, here is the 76-year correlation between Solar Flux and the Winter NAO.. Nov-Feb being the strongest correlation:

Here's the 76-year regression average:

SLP

 

 Thank you, Chuck. Great stuff! This tells me it isn’t a coincidence that the only 6 -NAO winters since 1979-80 were during weak portions of the solar cycle. Thus, I’m looking for the next good shot at a -NAO winter or two to be in the late 2020s to early 2030s.

[frd]

5 hours ago, GaWx said:

 Thank you, Chuck. Great stuff! This tells me it isn’t a coincidence that the only 6 -NAO winters since 1979-80 were during weak portions of the solar cycle. Thus, I’m looking for the next good shot at a -NAO winter or two to be in the late 2020s to early 2030s.

Even so,  without a great PAC decent winters in the east are over.  - NAO has little impact in the winter in the East  it seems the last 6 years. 

[bluewave]

7 hours ago, GaWx said:

 Thank you, Chuck. Great stuff! This tells me it isn’t a coincidence that the only 6 -NAO winters since 1979-80 were during weak portions of the solar cycle. Thus, I’m looking for the next good shot at a -NAO winter or two to be in the late 2020s to early 2030s.

Some of the recent studies found that it was a coincidence and others not. 
 

Just a coincidence

https://news.climate.columbia.edu/2019/01/22/debunking-solar-cycle-north-atlantic-winter-weather-connection/

Some signal possible in February

https://acp.copernicus.org/articles/22/7893/2022/

 

 

[Terpeast]

44 minutes ago, bluewave said:

Some of the recent studies found that it was a coincidence and others not. 
 

Just a coincidence

https://news.climate.columbia.edu/2019/01/22/debunking-solar-cycle-north-atlantic-winter-weather-connection/

Some signal possible in February

https://acp.copernicus.org/articles/22/7893/2022/

 

 

Interesting. It’s not clear from the article debunking the link what the statistical significance they found between nao and solar, and the research paper they linked to is paywalled. The other link that tries to find a link for February doesn’t really make a convincing case for it, imho. 

I’ll see if I can derive the p-value between those datasets broken down by month, just to satisfy my curiosity. If its well over 0.05 for all DJF months, that’s productive because I know I wouldn’t waste any more time on solar when predicting whether there will be blocking in the nao domain or not. 

[GaWx]

1 hour ago, bluewave said:

Some of the recent studies found that it was a coincidence and others not. 
 

Just a coincidence

https://news.climate.columbia.edu/2019/01/22/debunking-solar-cycle-north-atlantic-winter-weather-connection/

Some signal possible in February

https://acp.copernicus.org/articles/22/7893/2022/

 

 

This is what I posted in last year’s ENSO thread on 8/23/23:

Over the last 44 winters, -NAOs (I define as sub -0.25) for DJF have been few and far between:

1984-5: (NAO -0.70) (moderate La Niña) headed down in cycle 21 with limited sunspots averaging only 20/month; this was 20 months before the minimum of Sept 1986

1986-7: (NAO -0.30) (moderate El Niño) very early in cycle 22 four months after the Sept 86 minimum with very limited sunspots of only 6/month 

1995-6: (NAO -0.62) (moderate La Niña) headed down in cycle 22 with limited sunspots of only 12/month nine months before Sept 1996 minimum

2009-10: (NAO -1.67) (strong El Niño) one year into cycle 24 at 13 months after the Dec 2008 minimum just starting to head upward but with still limited sunspots of only 22/month

2010-11: (NAO -0.68) (strong La Niña) two years into cycle 24 at 25 months after the Dec 2008 minimum headed further up but still low at 33/month

2020-1: (NAO -0.42) (moderate La Niña) early into cycle 25 at 13 months after the Dec of 2019 minimum just starting to head up but still with limited sunspots of only 14/month

---------------------

 Note that there has been either one or two -NAO winters during each of the last four quiet portions of the cycles!

 So, based on the last 44 years of -NAO winters, the data clearly shows that being within two years of a minimum (ascending or descending) along with limited sunspots (so, nowhere near a cycle max) has given the best chance for a -NAO winter. The average distance from minimum was only 14 months.

 So, for these last six -NAO winters, the average monthly sunspots were all low to very low: 20, 6, 12, 22, 33, and 14 for an average of only 18. This 18 compares to the longtime average monthly sunspots of 85 (based on 1900-2022 data).

  

Monthly NAO since 1950:

https://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/norm.nao.monthly.b5001.current.ascii.table

 

Monthly sunspots:

https://www.sidc.be/SILSO/DATA/SN_m_tot_V2.0.txt

 

@Stormchaserchuck1@Terpeast

[snowman19]

3 hours ago, GaWx said:

This is what I posted in last year’s ENSO thread on 8/23/23:

Over the last 44 winters, -NAOs (I define as sub -0.25) for DJF have been few and far between:

1984-5: (NAO -0.70) (moderate La Niña) headed down in cycle 21 with limited sunspots averaging only 20/month; this was 20 months before the minimum of Sept 1986

1986-7: (NAO -0.30) (moderate El Niño) very early in cycle 22 four months after the Sept 86 minimum with very limited sunspots of only 6/month 

1995-6: (NAO -0.62) (moderate La Niña) headed down in cycle 22 with limited sunspots of only 12/month nine months before Sept 1996 minimum

2009-10: (NAO -1.67) (strong El Niño) one year into cycle 24 at 13 months after the Dec 2008 minimum just starting to head upward but with still limited sunspots of only 22/month

2010-11: (NAO -0.68) (strong La Niña) two years into cycle 24 at 25 months after the Dec 2008 minimum headed further up but still low at 33/month

2020-1: (NAO -0.42) (moderate La Niña) early into cycle 25 at 13 months after the Dec of 2019 minimum just starting to head up but still with limited sunspots of only 14/month

---------------------

 Note that there has been either one or two -NAO winters during each of the last four quiet portions of the cycles!

 So, based on the last 44 years of -NAO winters, the data clearly shows that being within two years of a minimum (ascending or descending) along with limited sunspots (so, nowhere near a cycle max) has given the best chance for a -NAO winter. The average distance from minimum was only 14 months.

 So, for these last six -NAO winters, the average monthly sunspots were all low to very low: 20, 6, 12, 22, 33, and 14 for an average of only 18. This 18 compares to the longtime average monthly sunspots of 85 (based on 1900-2022 data).

  

Monthly NAO since 1950:

https://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/norm.nao.monthly.b5001.current.ascii.table

 

Monthly sunspots:

https://www.sidc.be/SILSO/DATA/SN_m_tot_V2.0.txt

 

@Stormchaserchuck1@Terpeast

Good info. Low geomag figures into it too 

[40/70 Benchmark]

21 hours ago, bluewave said:

My is guess is that 10-11 was more about the 150 year -NAO event lingering from the previous year than it was about the La Niña. That historic blocking pattern began during the 09 summer with one of the coolest June-July periods on record around NYC. It carried through the 09-10 winter and reversed in early February 11. So it’s unlikely that we ever see the 09-10 all-time snowfalls in the Mid-Atlantic surpassed during an El Niño or any other ENSO state. Same goes for over 60” of snow in only 33 days around NYC in 10-11 during a La Niña or any other ENSO state. 
 

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2011GL046786

The winter of 2009/2010 was one of the most negative winters of the North Atlantic Oscillation (NAO) during the last 150 years. While most operational extended-range forecasting systems had difficulties in predicting the onset of the negative NAO phase, once established, extended-range forecasts were relatively skilful in predicting its persistence. Here, the origin and predictability of the unusual winter of 2009/10 are explored through numerical experimentation with the ECMWF Monthly forecasting system. More specifically, the role of anomalies in sea surface temperature (SST) and sea ice, the tropical atmospheric circulation, the stratospheric polar vortex, solar insolation and near surface temperature (proxy for snow cover) are examined. None of these anomalies is capable of producing the observed NAO anomaly, especially in terms of its magnitude. The results of this study support the hypothesis that internal atmospheric dynamical processes were responsible for the onset and persistence of the negative NAO phase during the 2009/10 winter.

 

I think the La Niña being somewhat biased to the east helped, too.....you won't find an appreciably potent Modoki La Niña with much blocking.

[40/70 Benchmark]

15 hours ago, Stormchaserchuck1 said:

May-Sept SST correlation with following Dec-Mar NAO (strong)  (shown below is +NAO correlation. -NAO would be opposite). 

Current SSTs

I thought it was May-Aug?

[bluewave]

30 minutes ago, 40/70 Benchmark said:

I think the La Niña being somewhat biased to the east helped, too.....you won't find an appreciably potent Modoki La Niña with much blocking.

What was interesting about the 09-10 and 10-11 winters is that the record Atlantic blocking developed during June and July of 2009 and carried over into early 2011. The record NE Pacific blocking also developed in June and July of 2013 and carried into early 2015. Someone should do an in depth study as to why the winter patterns emerged during the summer first. Plus to set records for NE Pacific and Atlantic blocking from 2009 to 2015 so close together was very impressive. All-time snowfall records were set in this period from DC to Philly and Boston. NYC and Long Island couldn’t rival 95-96 since the snowfall  ended too soon near the end of January in 2011. 

[GaWx]

 I took the sunspot cycle graph I posted above and drew in yellow lines when the 6 -NAO winters since 1979-80 occurred to give a better view of where they were in the solar cycles. You can clearly see that they were all during the weak parts of all of the cycles (1-2 during each weak period): sunspots averaged only 18 (range 6-33) vs 1900-2022 avg of 85 and were within 2 yrs of a min:

[Stormchaserchuck1]

44 minutes ago, 40/70 Benchmark said:

I thought it was May-Aug?

May-Sept.. we are 40% of the way through 

Here is Sept SST correlation with Jan-Feb NAO

[40/70 Benchmark]

27 minutes ago, bluewave said:

What was interesting about the 09-10 and 10-11 winters is that the record Atlantic blocking developed during June and July of 2009 and carried over into early 2011. The record NE Pacific blocking also developed in June and July of 2013 and carried into early 2015. Someone should do an in depth study as to why the winter patterns emerged during the summer first. Plus to set records for NE Pacific and Atlantic blocking from 2009 to 2015 so close together was very impressive. All-time snowfall records were set in this period from DC to Philly and Boston. NYC and Long Island couldn’t rival 95-96 since the snowfall  ended too soon near the end of January in 2011. 

2014-2015 was more of a rival to 1995-1996 in SNE ...the dry March caused it to fall a foot shy IMBY, but Boston of course caught it.

[40/70 Benchmark]

8 minutes ago, Stormchaserchuck1 said:

May-Sept.. we are 40% of the way through 

Here is Sept SST correlation with Jan-Feb NAO

I think it will obviously be a positive NAO winter, but I don't think it will be essentially wall-to-wall like some seasons. I think we could have a good month.

[Stormchaserchuck1]

36 minutes ago, 40/70 Benchmark said:

I think it will obviously be a positive NAO winter, but I don't think it will be essentially wall-to-wall like some seasons. I think we could have a good month.

Month-by-month of La Nina/+QBO vs El Nino/-QBO looks like this:

Nov

Super warm Nov may even out the Dec composite, since it only goes back to 1979

Jan

Feb

Mar

I always think La Nina is a colder weather pattern, since it has to do with colder waters.. if you ran it out like 200-300 years.. so maybe we'll have some -EPO periods this Winter, they usually last 7-12 days at a time.. but Feb and March for the last 7 years have been especially RNA. I don't see that trend not continuing:

[40/70 Benchmark]

2 hours ago, Stormchaserchuck1 said:

Month-by-month of La Nina/+QBO vs El Nino/-QBO looks like this:

Nov

Super warm Nov may even out the Dec composite, since it only goes back to 1979

Jan

Feb

Mar

I always think La Nina is a colder weather pattern, since it has to do with colder waters.. if you ran it out like 200-300 years.. so maybe we'll have some -EPO periods this Winter, they usually last 7-12 days at a time.. but Feb and March for the last 7 years have been especially RNA. I don't see that trend not continuing:

Thanks....looks like maybe a decent December....I would take that and run.

[raindancewx]

New Canadian run should be in shortly. July is often the first decent read for winter SSTs.

Some of the recent La Ninas didn't really develop until July. 2017-18 is one that comes to mind. That year the subsurface dropped off a cliff in July after muddling around in the Spring. Will be curious to see how that goes.

We're not really near La Nina conditions yet at the surface. The -0.5C or colder waters are all in Nino 3 or east. The dark blue has to fill in from 5N to 5S from 120-170W.

[mitchnick]

2 hours ago, raindancewx said:

New Canadian run should be in shortly. July is often the first decent read for winter SSTs.

Some of the recent La Ninas didn't really develop until July. 2017-18 is one that comes to mind. That year the subsurface dropped off a cliff in July after muddling around in the Spring. Will be curious to see how that goes.

We're not really near La Nina conditions yet at the surface. The -0.5C or colder waters are all in Nino 3 or east. The dark blue has to fill in from 5N to 5S from 120-170W.

It's in on Tropical Tidbits.  Niña is weaker than last month. December the coldest month.

https://www.tropicaltidbits.com/analysis/models/?model=cansips&region=global&pkg=ssta_noice&runtime=2024070100&fh=5

 

[raindancewx]

Help us Roni-Wan-Kenobi, you're our only hope. Actually, that's a much colder winter for the east to be honest.

Old

New

Aug-Oct is when I thought the -WPO might start to break from last year and stick around. The Canadian has that period pretty cold now in the US, with -WPO conditions in Sept/Oct it looks like.

Looks like a classic cold North-Central, warm rest of the US La Nina look. That's not crazy to me if the hurricane season doesn't go ballistic, especially if the -WPO remains negative. La Ninas tends to dump cold North Central or into the West, it just depends on the WPO / La Nina state.

[raindancewx]

Also, the MJO now looks like a coherent phase 4/5 blend on the global DJF precipitation map from the Canadian.

[George001]

As someone who was on the strong Niña train, the latest obs have not been impressive at all. The subsurface has actually warmed, and it is still ENSO neutral (if anything it’s warm neutral in the ENSO 3.4 region). Thats something worth watching.

[Stormchaserchuck1]

16 hours ago, frd said:

Even so,  without a great PAC decent winters in the east are over.  - NAO has little impact in the winter in the East  it seems the last 6 years. 

Yeah, since 2018-19, -NAO's have been more warm than cold. I've noticed a -NAO/-PNA or +EPO and +NAO/+PNA or -EPO correlation of about 0.40 during that time. Going back to since 2013, it's been about 0.25-0.30. 

[Stormchaserchuck1]

15 hours ago, bluewave said:

Some of the recent studies found that it was a coincidence and others not. 
 

Just a coincidence

https://news.climate.columbia.edu/2019/01/22/debunking-solar-cycle-north-atlantic-winter-weather-connection/

Some signal possible in February

https://acp.copernicus.org/articles/22/7893/2022/

 

 

I don't think we really have enough data.. and there are all kinds of different things that happen with the sun that effect us in different ways. I did correlate Jupiter's movement in the sky with the NAO before, it was pretty strong at its peak, like +30%. I think the actual correlation with Solar Max to +NAO is probably lower than the +0.2 to +0.3 those charts show. I would think it may even fuel a High pressure over Greenland, and a more volatile pattern. 

[GaWx]

 The June 2024 SOI came in at -5. For La Niña immediately following El Niño since 1876-7 with a 3 month 3.4 SSTa dip to -1.0 or lower (using RONI for 1949-50+), here was the preceding June SOI:

1886: +4

1889: +18

1924: +7

1942: +7

1970: +9

1973: +10

1983: -3

1988: -4

1998: +8

2007: +5

2010: +1

2016: +4

 AVG: +6

 

 So, the June 2024 of -5 is much higher than the June SOI avg of +6 for moderate to strong La Niña immediately following El Niño. However, it is only barely higher than the -4 of June 1988 and the -3 of June 1983. So, there’s still a reasonable shot at a RONI dip to -1 or lower this autumn though that chance has clearly dropped over the last month.

[Stormchaserchuck1]

13 hours ago, GaWx said:

This is what I posted in last year’s ENSO thread on 8/23/23:

Over the last 44 winters, -NAOs (I define as sub -0.25) for DJF have been few and far between:

1984-5: (NAO -0.70) (moderate La Niña) headed down in cycle 21 with limited sunspots averaging only 20/month; this was 20 months before the minimum of Sept 1986

1986-7: (NAO -0.30) (moderate El Niño) very early in cycle 22 four months after the Sept 86 minimum with very limited sunspots of only 6/month 

1995-6: (NAO -0.62) (moderate La Niña) headed down in cycle 22 with limited sunspots of only 12/month nine months before Sept 1996 minimum

2009-10: (NAO -1.67) (strong El Niño) one year into cycle 24 at 13 months after the Dec 2008 minimum just starting to head upward but with still limited sunspots of only 22/month

2010-11: (NAO -0.68) (strong La Niña) two years into cycle 24 at 25 months after the Dec 2008 minimum headed further up but still low at 33/month

2020-1: (NAO -0.42) (moderate La Niña) early into cycle 25 at 13 months after the Dec of 2019 minimum just starting to head up but still with limited sunspots of only 14/month

---------------------

 Note that there has been either one or two -NAO winters during each of the last four quiet portions of the cycles!

 So, based on the last 44 years of -NAO winters, the data clearly shows that being within two years of a minimum (ascending or descending) along with limited sunspots (so, nowhere near a cycle max) has given the best chance for a -NAO winter. The average distance from minimum was only 14 months.

 So, for these last six -NAO winters, the average monthly sunspots were all low to very low: 20, 6, 12, 22, 33, and 14 for an average of only 18. This 18 compares to the longtime average monthly sunspots of 85 (based on 1900-2022 data).

  

Monthly NAO since 1950:

https://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/norm.nao.monthly.b5001.current.ascii.table

 

Monthly sunspots:

https://www.sidc.be/SILSO/DATA/SN_m_tot_V2.0.txt

 

@Stormchaserchuck1@Terpeast

I've seen your research before about how rare -NAO's have been lately. I've done my own research that shows that 16/16 of the Winter months (DJFM) since 2013, with a NAO >1.11 have all been positive!

Also I found that the Winter NAO has been positive something like 37 of the last 43 Winter months. The big differences started in the early 2010s (2013-2024). 

There was something I was reading that showed Atlantic sea levels rising/falling 2011-2022 to fit a perfect +NAO progression. 

But the CPC's measurement is weird. We have had some strong Greenland blocks lately, and not very negative NAO readings. I think they heavily weight the mid-latitude region at about 40-45N that runs from the east coast to the central-north Atlantic. That region has been warmer, making that part of their NAO measurement positive, despite high pressures in the Upper latitudes at the same times. This has especially occurred since the Winter of 2018-19.  You might just want to run H5 anomaly maps and make your own NAO index. 

[Stormchaserchuck1]

1 hour ago, George001 said:

As someone who was on the strong Niña train, the latest obs have not been impressive at all. The subsurface has actually warmed, and it is still ENSO neutral (if anything it’s warm neutral in the ENSO 3.4 region). Thats something worth watching.

Subsurface and the surface are far apart.. but the global pattern is more like the subsurface, saying we are in a Weak Nina, than the surface saying +Neutral. I've researched this back long ways, and found the subsurface has greater correlations to the global pattern than surface SSTs, so if there are differences between the two, I lean toward subsurface being the greater variable. 

It's holding -3c anomalies in the central region at -200m, and that has organized a bit in the last day or so... so let's see if these -3 to -4c readings in the central subsurface continue to hold like they have been since February..

A Strong La Nina peak does not look very possible. Almost all of those years had more La Nina stuff happening right now.  

[Stormchaserchuck1]

1 hour ago, GaWx said:

 The June 2024 SOI came in at -5. 

Apr-May-Jun SOI average comes in at -2

The highest monthly reading we've actually had since March 2023 is +3.96.