2025-2026 ENSO

[40/70 Benchmark]

11 hours ago, Stormchaserchuck1 said:

13-14 was a really rare N. Hemisphere 500mb is very unlikely to happen again for a long time. Probably >1/100 year occurrence with such a strong +NAO and cold. For variance, we've never come close to having a strong -NAO with such above average temps, although since 2013 there has been a weaker -NAO/warm EC correlation.

2014-2015 was even more anomalous in that respect.

[40/70 Benchmark]

1 minute ago, donsutherland1 said:

That's the only paper I could find related to ACE and the NAO or AO. 

Yea, I never doubt any of your research......just saying, not what I would have guessed.

[40/70 Benchmark]

12 hours ago, raindancewx said:

The Canadian update shows a cool Fall for the East (Sept-Nov) with La Nina dead by February, likely dying mid-January. May not last long enough to be official, but will be La Nina in practice. Cold winter for the Northern US.

I suspect the cool Fall idea is right but overdone. Canadian had the right idea for August but it was a bit too cold. Wet Junes locally often precede a fluke/heavy out of winter snow events. So cold availability in the transitions to/from Winter, but not Winter itself is consistent with my expectations for seasonal behavior locally. I'm expecting a small number of very powerful lows with a lot of cold and moisture in the Fall here (likely mid-Oct to mid-Nov if I had to guess) and then again in Spring (mid-Feb to early Apr). Actual winter should be warm, although I do think the models are overdoing the dryness nationally for winter right now.

If the hurricane season remains inactive, I'd also expect a pretty major cold wave again when or just after the La Nina collapses, likely focused on the Northern and Western US. ACE is about to dip below average again and low La Nina ACE is correlated with more frequent cold days in the Southwest in Nov-Feb.

100% agree here...been my stance all along.

[bluewave]

5 hours ago, PhiEaglesfan712 said:

If there is a la nina, then hope for something weak (like 17-18). A moderate la nina is not going to be favorable for the winter (like 11-12 and 22-23).

It used to work out that way more often before 2010-2011. But for some reason things have reversed since then. So the weaker RONI winters of the multiyear events turned out to be the warmer winters. 

https://www.cpc.ncep.noaa.gov/data/indices/RONI.ascii.txt

DJF  2023 -0.83…warmest winter of the 3 year La Niña

DJF  2022 -1.21

DJF  2021 -1.17

DJF  2018 -1.10

DJF  2017 -0.73…warmest winter of 2 year La Nina

DJF  2012 -0.82…warmest winter of 2 year La Niña

DJF  2011 -1.42

 

 

 

 

 

 

 

[snowman19]

6 minutes ago, 40/70 Benchmark said:

Yea, I never doubt any of your research......just saying, not what I would have guessed.

Me either. Up until right now, everything I have seen on this topic has tied high Atlantic ACE, not low Atlantic ACE to a -NAO 

[anthonymm]

Any reason why winters in the tristate area show their cards in December? December snowfall is pretty much the biggest indicator of whether the rest of the winter will be snowy or not. Very few low snow Decembers result in a good winter, and almost all snowy December result in snowy january-februaries.

[40/70 Benchmark]

35 minutes ago, snowman19 said:

Me either. Up until right now, everything I have seen on this topic has tied high Atlantic ACE, not low Atlantic ACE to a -NAO 

It may just be an issue for more research needing to be done on the topic...it's bad enough that ur sample size is so low, but I feel like having only one piece of research on top exacerbates that issue.

[40/70 Benchmark]

1 minute ago, anthonymm said:

Any reason why winters in the tristate area show their cards in December? December snowfall is pretty much the biggest indicator of whether the rest of the winter will be snowy or not. Very few low snow Decembers result in a good winter, and almost all snowy December result in snowy january-februaries.

Well, when you average 20", scoring 12" the first month kind of seals the deal.

[40/70 Benchmark]

41 minutes ago, bluewave said:

It used to work out that way more often before 2010-2011. But for some reason things have reversed since then. So the weaker RONI winters of the multiyear events turned out to be the warmer winters. 

https://www.cpc.ncep.noaa.gov/data/indices/RONI.ascii.txt

DJF  2023 -0.83…warmest winter of the 3 year La Niña

DJF  2022 -1.21

DJF  2021 -1.17

DJF  2018 -1.10

DJF  2017 -0.73…warmest winter of 2 year La Nina

DJF  2012 -0.82…warmest winter of 2 year La Niña

DJF  2011 -1.42

 

 

 

 

 

 

 

May be tied to your October MJO rule...or a coincidence.

[anthonymm]

Just now, 40/70 Benchmark said:

Well, when you average 20", scoring 12" the first month kind of seals the deal.

Central park's average is 30". If you use the older climo then it's like 25". Still though, even just a December with at least 5" is very strongly correlated to the total snow for the season.

[GaWx]

3 hours ago, donsutherland1 said:

Since ACE is often brought up with regard to looking ahead to the winter. Here's what the literature has to say.

In general, Atlantic hurricane activity has some relationship to the winter NAO. The connection is indirect and expressed through the NAO. High ACE seasons are linked to winters with a tendency for positive NAO. Low ACE seasons are linked to a tendency for a negative NAO. For purposes of assessing ACE, ACE is measured from the start of hurricane season to early September. These relationships are strongest during ENSO neutral winters. Many other factors contribute to the overall winter outcome.

 

Thanks, Don!

 The linked article refers to both overall “Atlantic hurricane activity” (ACE-like) and  “US hurricane activity”. However, those two things have a decent correlation to each other. So, maybe it works for both. Also, it says as you said that it looks only through “early Sept.” or midpoint of season. So, I’ll assume 9/10 as the cutoff.

 Out of curiosity because there have been only 5 sub -0.25 DJF NAOs from the early 1980s through the year the article was written (2016), which is the period the article says works best for DJF NAO, I looked at the 5 seasons preceding those winters through Sept 10th. I’m keeping these in mind:

-Avg ACE through Sept 10 is ~55 (varies with era)
 
 -Avg # of CONUS H hits through Sept 10th 1980-2016 is 0.9

 

1. 1984-5: 

-no US H hits through 9/10 (BN): works

-ACE through 9/10 was 7.9 (far BN): works

 

2. 1986-7: 

-2 US H hits through 9/10 (AN): doesn’t work

-ACE through 9/10 was 12.3 (far BN): works 

 

3. 1995-6:

-1 US H hit through 9/10 (near avg): no signal to work with

-ACE through 9/10 was 153.9 (near record high with only one season, 1933, possibly higher): doesn’t work (major fail)

4. 2009-10:

-0 US H hits through 9/10 (BN): works 

-ACE through 9/10 was 38.8 (slightly BN): works

 

5. 2010-1: 

-0 US H hits through 9/10 (BN): works

-ACE through 9/10 was 64.6 (slightly AN): doesn’t work

——————

So, for these 5 -NAO winters:

-# of US H hits through 9/10: worked three times and didn’t work once (1995 had a lack of signal)

-ACE through 9/10: worked three times and didn’t work twice (including 1995’s huge fail)

—————

 Out of curiosity, I checked the 2020 H season because of the 2020-1 -NAO DJF:

-3 US H hits through 9/10: doesn’t work

-ACE through 9/10 was 50.5 (NN): no signal to work with 

@40/70 Benchmark@snowman19

[snowman19]

1 hour ago, 40/70 Benchmark said:

It may just be an issue for more research needing to be done on the topic...it's bad enough that ur sample size is so low, but I feel like having only one piece of research on top exacerbates that issue.

Just off the top of my head it definitely did not work in 2013….low Atlantic ACE, cold-neutral ENSO and one of the most positive NAO/AO winters in recorded history 

[bluewave]

1 hour ago, anthonymm said:

Any reason why winters in the tristate area show their cards in December? December snowfall is pretty much the biggest indicator of whether the rest of the winter will be snowy or not. Very few low snow Decembers result in a good winter, and almost all snowy December result in snowy january-februaries.

My guess is that it’s related to La Niña winters typically being frontloaded by nature for cold and snow. A weak start to the snowfall continues for the whole season. With a snowy start continuing for the whole season.

So if the stations near NYC stay under 4” in December, then it’s a below average snowfall signal for the whole season. Go above 4” in December and it has usually been a snowy season.

This relationship has worked for 14 out of the last 15 La Ninas since 95-96 including the recent 24-25 La Niña winter season.

[anthonymm]

1 minute ago, bluewave said:

My guess is that it’s related to La Niña winters typically being frontloaded by nature for cold and snow.

So if the stations near NYC stay under 4” in December, then it’s a below average snowfall signal for the whole season. Go above 4” in December and it has usually been a snowy season.

This relationship has worked for 14 out of the last 15 La Ninas since 95-96. 

I can see that for ninas. If you dont get a good December even in a nina you're cooked. But what about ninos?

[snowman19]

Take it FWIW, but If (IF) this is correct, pray for a -EPO winter again

[bluewave]

4 minutes ago, anthonymm said:

I can see that for ninas. If you dont get a good December even in a nina you're cooked. But what about ninos?

El Ninos don’t follow the pattern as closely. Some El Niños with weak snowfall starts like 23-24 follow up with below average snowfall. But some years like 15-16 with a T of snow in December did very well for the whole season. 

[anthonymm]

14 minutes ago, bluewave said:

El Ninos don’t follow the pattern as closely. Some El Niños with weak snowfall starts like 23-24 follow up with below average snowfall. But some years like 15-16 with a T of snow in December did very well for the whole season. 

I see. I guess el ninos are typically more boom or bust, with one or two huge storms making the whole season. Just need to time that active subtropical jet with one good cold shot.

[GaWx]

1 hour ago, snowman19 said:

Just off the top of my head it definitely did not work in 2013….low Atlantic ACE, cold-neutral ENSO and one of the most positive NAO/AO winters in recorded history 

Now I’ll look at the opposite end:

NAO>+1 DJF 1980-1 through 2015-6

1988-9, 1993-4, 1994-5, 1999-00, 2011-2, 2014-5, and 2015-6

 

1. 1988: 

-1 H hit (NN): no signal

-ACE ~12 (far BN): doesn’t work (major fail)

 

1993:

-1 H hit (NN): no signal

-ACE ~33 (BN): doesn’t work

 

1994:

-0 H hits (BN): doesn’t work

-ACE ~12 (far BN): doesn’t work (major fail)

 

1999:

-1 H hit (NN): no signal

-ACE ~66 (slightly AN): works

 

2011:

-1 H hit (NN): no signal

-ACE ~71 (AN): works

 

2014:

-1 H hit (NN): no signal

-ACE 21.2 (BN): doesn’t work

 

2015: 

-0 H hits (BN): doesn’t work

-ACE 26.4 (BN): doesn’t work

——————————

Summary for the seven +1+ NAO winters 1980-1 through 2015-6

-# of US H hits through 9/10: no signal 5 times, didn’t work twice, and worked zero times

-ACE through 9/10: worked twice and didn’t work five times including two major fails

Summary: the seven +1+ NAO cases overall failed to support their theory and actually, if anything, supported the opposite!

@donsutherland1@40/70 Benchmark
 

Edit: If I include only the 3 neutral ENSO summers (JJA) (1993, 1994, 2014), that doesn’t help and even makes it worse because none worked for ACE (including one major fail). The one with a signal for # of US H hits didn’t work.

[donsutherland1]

32 minutes ago, GaWx said:

Now I’ll look at the opposite end:

NAO>+1 DJF 1980-1 through 2015-6

1988-9, 1993-4, 1994-5, 1999-00, 2011-2, 2014-5, and 2015-6

 

1. 1988: 

-1 H hit (NN): no signal

-ACE ~12 (far BN): doesn’t work (major fail)

 

1993:

-1 H hit (NN): no signal

-ACE ~33 (BN): doesn’t work

 

1994:

-0 H hits (BN): doesn’t work

-ACE ~12 (far BN): doesn’t work (major fail)

 

1999:

-1 H hit (NN): no signal

-ACE ~66 (slightly AN): works

 

2011:

-1 H hit (NN): no signal

-ACE ~71 (AN): works

 

2014:

-1 H hit (NN): no signal

-ACE 21.2 (BN): doesn’t work

 

2015: 

-0 H hits (BN): doesn’t work

-ACE 26.4 (BN): doesn’t work

——————————

Summary for the seven +1+ NAO winters 1980-1 through 2015-6

-# of US H hits through 9/10: no signal 5 times, didn’t work twice, and worked zero times

-ACE through 9/10: worked twice and didn’t work five times including two major fails

Summary: the seven +1+ NAO cases overall failed to support their theory and actually, if anything, supported the opposite!

@donsutherland1@40/70 Benchmark
 

Edit: If I include only the 3 neutral ENSO summers (JAS) (1993, 1994, 2014), that doesn’t help and even makes it worse because none worked for ACE (including one major fail) and the one with a signal for # of US H hits didn’t work.

Unfortunately, the paper doesn't mention the statistical threshold that was used to determine a statistically significant relationship. I suspect that it's far less than a 90% or 95% threshold. Based on the outcomes you posted, which is very mixed, I don't think ACE is a useful predictor. Anecdotally, it may seem to hold some value, but not on a consistent or rigorous basis.

[mitchnick]

54 minutes ago, snowman19 said:

Take it FWIW, but If (IF) this is correct, pray for a -EPO winter again
 

Unfortunately, that private company, despite their name, has got to find something on every model run to pimp their pov. Temp difference in the east between the 2 runs is negligible without a mention of it in their post.

[bluewave]

On 8/30/2025 at 8:23 PM, Stormchaserchuck1 said:

^Yeah the Great Lakes trough for around 9/4 was not even on models 7-10 days ago. Now it's expected to be -400dm and actually closes off for a little while. I've been noticing weak projections on ensemble means >11 days out. I wonder why that is. 

Started seeing some wave breaking activity right around the time we had the big cat 5 recurve with Erin a few weeks ago. So this helped to reinforce the cooler trough pattern in the East.

It’s been nice having the trough in the Northeast from late August into early September following the record June and July heat. The record low pressure north of Alaska may have been a part of this pattern. 

 

[michsnowfreak]

15 hours ago, Stormchaserchuck1 said:

13-14 was a really rare N. Hemisphere 500mb is very unlikely to happen again for a long time. Probably >1/100 year occurrence with such a strong +NAO and cold. For variance, we've never come close to having a strong -NAO with such above average temps, although since 2013 there has been a weaker -NAO/warm EC correlation.

Ive been saying since April 2014, we will never see another 2013-14 again in our lifetimes, referring to sensible weather. It wasnt just the snowiest winter on record. The combo of snow + cold + snow depth + wind had never been seen in the record era, and not even close.

[michsnowfreak]

27 minutes ago, bluewave said:

Started seeing some wave breaking activity right around the time we had the big cat 5 recurve with Erin a few weeks ago. So this helped to reinforce the cooler trough pattern in the East.

It’s been nice having the trough in the Northeast from late August into early September following the record June and July heat. The record low pressure north of Alaska may have been a part of this pattern. 

 

We didnt see extreme high temps here, but the warm muggy nights were placing the summer higher into the hottest summers list, but the last week of August was the 7th coldest on record for Detroit, plummeting the summer out of the top 20 hottest.

[snowman19]

49 minutes ago, mitchnick said:

Unfortunately, that private company, despite their name, has got to find something on every model run to pimp their pov. Temp difference in the east between the 2 runs is negligible without a mention of it in their post.

All they did was show the NAO. Nowhere in that tweet did they say +NAO = warm in the east nor did they even mention temps. I’m not sure what the gripe is, it is in fact showing a +NAO and no it’s not showing big warmth either, which was my point, separate from their tweet. If the NAO is really going to be that positive, then you would need -EPO assistance on the PAC side to avoid warmth in the east, which it evidently has

[GaWx]

1 hour ago, donsutherland1 said:

Unfortunately, the paper doesn't mention the statistical threshold that was used to determine a statistically significant relationship. I suspect that it's far less than a 90% or 95% threshold. Based on the outcomes you posted, which is very mixed, I don't think ACE is a useful predictor. Anecdotally, it may seem to hold some value, but not on a consistent or rigorous basis.

Thanks, Don.

 Although the study ended by 2016 (date of article), I was curious about how the theory worked after 2016 for DJF NAO >+1:

 These are those 4 winters: 2017-8, 2019-20, 2021-2, 2023-4

 

2017:

-2 H hits (AN): works

-ACE: ~119 (way AN): works

 

2019:

-2 H hits (AN): works

-ACE: 60 (NN): no signal

 

2021:

-1 H hit (NN): no signal

-ACE: 75.3 (AN): works

 

2023:

-1 H hit (NN): no signal

-ACE: 76.1 (AN): works

————

 Summary for these 4 2016+ >1 NAO

-# of US H hits through 9/10: worked twice, no signal twice, and didn’t work zero times

-ACE through 9/10: worked 3 times, no signal once, and didn’t work zero times

-So, for NAO >1: despite not doing well pre-2016 and despite 2020 not working for H hits as the only 2016+ -NAO winter, 2016+ for NAO >1 did much better for both measures with none not working.

[GaWx]

 Increased +NAO chances this JF on CANSIPS per this:

 

[michsnowfreak]

8 minutes ago, GaWx said:

 Increased +NAO chances this JF on CANSIPS per this:

 

Im seeing double