2025-2026 ENSO

[GaWx]

12 minutes ago, snowman19 said:

The question remains….is the ACE/recurving hurricanes causing it? Or is the larger background state of the Atlantic at the time causing it and it’s only a symptom?

1. It’s a weak to very weak correlation at best regarding AN ACE to 35”+ NYC snow. Furthermore, correlation doesn’t necessarily mean causation.

2. If either of the two possibilities were to be the case even in a weak manner, I’d go with your 2nd option.

3. I’ve seen no indication about an even very weak correlation of recurving hurricanes and 35”+ NYC snow.

4. If anything, there may be a very weak correlation to seasons with 2+ US H hits and not the other way around. That sort of seems like the opposite 

5. Regardless, how does one quantify the relationship of “recurving hurricanes” to 35”+ snowfall? That seems kind of vague/not very concrete.

[mitchnick]

24 minutes ago, GaWx said:

 

5. Regardless, how does one quantify the relationship of “recurving hurricanes” to 35”+ snowfall? That seems kind of vague/not very concrete.

It's whatever Joe Bastardi says it is!

@snowman19

[anthonymm]

7 hours ago, bluewave said:

While the sample size is pretty small, there has been an increase in NYC La Niña snowfall following Atlantic hurricane seasons with 160+ ACE since 1995. There was also an increase in December +PNAs. Unfortunately, the relationship didn’t work last winter due to the overpowering Northern Stream of the Pacific Jet.

Last season was the first with only 12.9” of snowfall in NYC with a strong December +PNA and a La Niña.

My guess is that the high ACE was part of a similar pattern which used to produce both December +PNAs and snowy outcomes during La Nina’s. So while we got the strong December +PNA last season, the snowfall didn’t follow due to the warm storm track through the Great Lakes. 

So several elements in the same pattern but we can’t say that the ACE is directly the cause. Just that these elements appear together from time to time. It could be they are related to another underlying variable that we haven’t identified yet. 

2005….ACE…..245….DEC PNA….+1.38….NYC snowfall….40.0”

1995….ACE……227….DEC PNA…..+0.92..NYC snowfall ….75.6”

2017….ACE……224….DEC PNA…..+0.89…NYC snowfall….40.9”

1998…ACE……181……DEC PNA…..-0.09….NYC snowfall…..12.7”

2020..ACE……180…..DEC PNA…..+1.58….NYC snowfall….38.6”

1999…ACE……176…..DEC PNA……+0.21….NYC snowfall…..16.3”

2010…ACE…..165……DEC PNA…….-1.78….NYC snowfall…..61.9”

2024…ACE….161……DEC PNA…….+1.70….NYC snowfall…..12.9”

 

Crazy rotten luck last winter for nyc. It's very rare nowadays to get below normal temps and snow.

[snowman19]

Trade winds/EWBs look to strengthen significantly in the coming couple of weeks which will enhance a more La Niña and -AAM regime as we go into met fall

[PhiEaglesfan712]

If we get a la nina, we better hope it doesn't torch, or the winter is pretty much toast. I know that one storm is all that's needed to skew the winter, but getting that one storm is tougher in a torch la nina (since the weather generally has a lot less variance during a la nina, I mean what happens in late November and December pretty much sets the tone for the rest of the winter). Just look at the last 3 la nina torch winters:

11-12: BWI snowfall 1.8 in; DCA snowfall 2.0 in

16-17: BWI snowfall 3.0 in; DCA snowfall 3.4 in

22-23: BWI snowfall 0.2 in; DCA snowfall 0.4 in

[snowman19]

If we get a la nina, we better hope it doesn't torch, or the winter is pretty much toast. I know that one storm is all that's needed to skew the winter, but getting that one storm is tougher in a torch la nina (since the weather generally has a lot less variance during a la nina, I mean what happens in late November and December pretty much sets the tone for the rest of the winter). Just look at the last 3 la nina torch winters:
11-12: BWI snowfall 1.8 in; DCA snowfall 2.0 in
16-17: BWI snowfall 3.0 in; DCA snowfall 3.4 in
22-23: BWI snowfall 0.2 in; DCA snowfall 0.4 in

As a sweeping generality, -ENSO/-PDO winters tip their hand in November and December….if those 2 months are warmer than normal with below average snow, that usually sets the tone for the remainder of the winter season….the opposite (colder than normal with above average snow) normally also holds true

[anthonymm]

8 hours ago, PhiEaglesfan712 said:

If we get a la nina, we better hope it doesn't torch, or the winter is pretty much toast. I know that one storm is all that's needed to skew the winter, but getting that one storm is tougher in a torch la nina (since the weather generally has a lot less variance during a la nina, I mean what happens in late November and December pretty much sets the tone for the rest of the winter). Just look at the last 3 la nina torch winters:

11-12: BWI snowfall 1.8 in; DCA snowfall 2.0 in

16-17: BWI snowfall 3.0 in; DCA snowfall 3.4 in

22-23: BWI snowfall 0.2 in; DCA snowfall 0.4 in

Isn't nina looking less and less likely? Almost looks like a carbon copy of last winter (which was good for mid atlantic but meh for philly-nyc-coastal new england).

[snowman19]

Isn't nina looking less and less likely? Almost looks like a carbon copy of last winter (which was good for mid atlantic but meh for philly-nyc-coastal new england).

No it’s not. In fact, a La Niña Watch was just issued by the CPC/NOAA

[snowman19]

IMO, there is a high risk for a dry met fall (SON) again this year. I don’t think we see a record drought like last fall, but I can see us reach drought conditions none the less

[anthonymm]

3 hours ago, snowman19 said:

No it’s not. In fact, a La Niña Watch was just issued by the CPC/NOAA

Well that sucks. Nina is pretty much a winter killer if you're south of new england no?

[GaWx]

 NATL ACE has risen to 23.6, which is the 16th highest of the last 75 for the date.

 Based on the latest NHC prog, ACE would be ~42 as of late Aug 23. If that verifies, 2025 would move up to 9th or 10th of the last 75. It would also move up to ~19th or 20th of the last 175 years (~89th percentile).

 The only ones higher than 2025 as of Aug 23rd would be these:
2024, 2008, near tie with 2007, 2005, 1995, 1980, 1969, 1955, 1951, 1950, 1933, 1926, 1916, 1899, 1893, 1887, 1886, 1880, and 1871. 
2025 would be just ahead of 2004, 1966, and 1915.

@mitchnick@snowman19@PhiEaglesfan712

[GaWx]

1 hour ago, GaWx said:

 NATL ACE has risen to 23.6, which is the 16th highest of the last 75 for the date.

 Based on the latest NHC prog, ACE would be ~42 as of late Aug 23. If that verifies, 2025 would move up to 9th or 10th of the last 75. It would also move up to ~19th or 20th of the last 175 years (~89th percentile).

 The only ones higher than 2025 as of Aug 23rd would be these:
2024, 2008, near tie with 2007, 2005, 1995, 1980, 1969, 1955, 1951, 1950, 1933, 1926, 1916, 1899, 1893, 1887, 1886, 1880, and 1871. 
2025 would be just ahead of 2004, 1966, and 1915.

@mitchnick@snowman19@PhiEaglesfan712

To add to the above post:

 Of the 22 listed years, including the three 2025 is projected to be just ahead of as of August 23rd, only 2007 ended up with a BN total season ACE (averages based on their era).

 Of the other 21, all ended up the season well AN (based on their era’s average).

[Stormchaserchuck1]

^It seems the Euro ensembles are good at those long range forecasted hurricane numbers. I remember in the 2nd half of last season they had 5x average, and we sure did have an active period. 

[snowman19]

8 hours ago, anthonymm said:

Well that sucks. Nina is pretty much a winter killer if you're south of new england no?

No Nina’s are not a winter killer even south of New England

[snowman19]

IMO, there is a high risk for a dry met fall (SON) again this year. I don’t think we see a record drought like last fall, but I can see us reach drought conditions none the less

To add, the new 30 day QPF from the EPS is very dry for the mid-Atlantic and northeast. IF (if) correct, we will be in drought conditions again….

[PhiEaglesfan712]

The GFS showing a Sandy-like storm:

[MJO812]

10 hours ago, anthonymm said:

Well that sucks. Nina is pretty much a winter killer if you're south of new england no?

Depends on strength and other factors.  Right now we are looking at a weak La Nina.

[mitchnick]

3 minutes ago, MJO812 said:

Depends on strength and other factors.  Right now we are looking at a weak La Nina.

As previously mentioned, it will likely not technically reach a Niña  (5 consecutive tri-monthly SSTA of -.5C at ENSO 3.4), but other measurements like MEI and RONI likely will. So it shouldn't be overwhelming. 

[GaWx]

11 hours ago, anthonymm said:

Well that sucks. Nina is pretty much a winter killer if you're south of new england no?

Based on NYC 30”+ snowfall, a Niña wasn’t a winter killer in:

2020-1, 17-18, 16-17, 10-11, 05-06, 00-01, 95-6, 55-6, 38-9, 33-4, 17-8, 16-7, 03-4, 1893-4, 86-7, 72-3

 So, out of 43 La Niña winters including the unofficial 2024-5, 16 of them (37%) had 30”+ of snow at NYC.

Edit: Compare 37% to 61 of 156 (39%) of all winters since 1869-70 having had 30”+ there. So, virtually the same %.

[jm1220]

On 8/17/2025 at 3:55 PM, anthonymm said:

Crazy rotten luck last winter for nyc. It's very rare nowadays to get below normal temps and snow.

It’s not rotten luck. The Pacific Jet oriented in a way and strength that systematically destroyed our chances especially south of I-90 to PHL. Historically when it’s been cold enough in NYC it’s found a way to snow because there would be a PNA ridge that would stick around long enough or NAO blocking to slow the pattern down. Now the Pacific Jet knocks it all down like bowling pins and storms either can’t amplify in time or amplify too much. 

[jm1220]

13 minutes ago, GaWx said:

Based on NYC 30”+ snowfall, a Niña wasn’t a winter killer in:

2020-1, 17-18, 16-17, 10-11, 05-06, 00-01, 95-6, 55-6, 38-9, 33-4, 17-8, 16-7, 03-4, 1893-4, 86-7, 72-3

 So, out of 43 La Niña winters including the unofficial 2024-5, 16 of them (37%) had 30”+ of snow at NYC.

Nina in and of itself isn’t unfavorable for NYC, it’s more of a killer south of the M/D line though last winter was very good snow-wise even in the Deep South when the pattern deamplified. But NYC is in a particular Goldilocks geographic area where there isn’t a defined storm type that can be relied on to produce-we’ve had huge Miller B and more suppressed Miller A, and can if we’re lucky get 3-6” from a SWFE, just about all types other than cutter can produce for NYC but also be a dud. The fast Pacific along with the Nina arranged the pattern in such a way that it caused dud after dud despite cold enough air in place multiple times. 

[PhiEaglesfan712]

26 minutes ago, GaWx said:

Based on NYC 30”+ snowfall, a Niña wasn’t a winter killer in:

2020-1, 17-18, 16-17, 10-11, 05-06, 00-01, 95-6, 55-6, 38-9, 33-4, 17-8, 16-7, 03-4, 1893-4, 86-7, 72-3

 So, out of 43 La Niña winters including the unofficial 2024-5, 16 of them (37%) had 30”+ of snow at NYC.

Edit: Compare 37% to 61 of 156 (39%) of all winters since 1869-70 having had 30”+ there. So, virtually the same %.

16-17 doesn't really belong on this list. Sure, it technically made 30 inches of snow in NYC (and much of that was due to a mid-March snowstorm), but as you went more south, it was a terrible winter. PHL only got 15 inches of snow, and places like Baltimore and DC only got 3 inches of snow, and had a Top 10 least snowy winter.

Plus, all the other winters were near normal temperature (17-18 and 20-21), or well below average. 16-17 was a blow torch.

16-17 is one winter that had a very sharp cutoff, even more so than 07-08.

[BlizzardWx]

I always like to look at the spring pattern for a hint of how the next winter may evolve. Sometimes there can be some low frequency hints even further back. It's never in exactly the same spot, but if you look at the spring pattern the coming winter pattern often has a similar look, just shifted and amplified or deamplified. Spring 23 offered excellent hints about the winter of 23-24. Last winter wasn't quite as strong of a connection, but there were still hints of the east coast trough pattern as well as the ridging southwest of Greenland.

For this year we've seen some interesting changes compared to both the last two years. It appears the low frequency forcing for ridging southwest of Greenland was finally gone this year, which would be a change if that rolls forward into the winter. On the other hand the spring trough moved west with more ridging along the east coast than last year. Theoretically that could mean troughs wanting to dump further west this year if it holds. The Pacific is unchanged so probably some good AK ridging pops up again. Maybe this isn't the most robust method out there, but I've found it has some utility. 

[GaWx]

14 minutes ago, PhiEaglesfan712 said:

16-17 doesn't really belong on this list. Sure, it technically made 30 inches of snow in NYC (and much of that was due to a mid-March snowstorm), but as you went more south, it was a terrible winter. PHL only got 15 inches of snow, and places like Baltimore and DC only got 3 inches of snow, and had a Top 10 least snowy winter.

Plus, all the other winters were near normal temperature (17-18 and 20-21), or well below average. 16-17 was a blow torch.

16-17 is one winter that had a very sharp cutoff, even more so than 07-08.

Thanks.

 I was going by snowfall because that’s about all many here seem to care about. La Guardia had 33.2” and Kennedy had 30.9”. But good point about the sharp cutoff S of NYC.

 If I were to throw out 2016-7 due to the sharp cutoff, it would still be 35% of NYC winters with 30”+ vs 39% of all meaning only barely lower.

[BlizzardWx]

I'll mention too that the pattern coming up the last week of August looks like it'll be a lot like the spring pattern we just had down my way, with very wet and anomalously cool northwest flow. So I do think rolling forward the spring pattern (with appropriate modifications) will be useful this year as one of the many predictors. 

[FPizz]

16 minutes ago, GaWx said:

Thanks.

 I was going by snowfall because that’s about all many here seem to care about. La Guardia had 33.2” and Kennedy had 30.9”. But good point about the sharp cutoff S of NYC.

 If I were to throw out 2016-7 due to the sharp cutoff, it would still be 35% of NYC winters with 30”+ vs 39% of all meaning only barely lower.

It is always hard with snow, but your post still is accurate.  16-17 I had 28", so like 2" below average, and I'm 42 miles SW as the crow flies to NYC, but 44 miles NE of Philly, so almost right in the middle of both cities.  There was sharp cutoff that season, but that is the nature of total snow many years.  

[snowman19]

Thanks.
 I was going by snowfall because that’s about all many here seem to care about. La Guardia had 33.2” and Kennedy had 30.9”. But good point about the sharp cutoff S of NYC.
 If I were to throw out 2016-7 due to the sharp cutoff, it would still be 35% of NYC winters with 30”+ vs 39% of all meaning only barely lower.

If 16-17 didn’t see the strong -IOD form, it would have been another +ENSO winter, but much weaker. It still had the lingering +PDO and a strong +AMO. It was supposed to be a -QBO winter, but the super El Niño the winter before f-ed up the atmosphere/QBO progression so much that we went into another +QBO, which was a complete anomaly

[anthonymm]

So is 22-23 a good analog year? If so coastal mid atl-sne is screwed.

[GaWx]

29 minutes ago, anthonymm said:

So is 22-23 a good analog year? If so coastal mid atl-sne is screwed.

Even if 22-23 is a good analog winter, that’s only one analog, which has little statistical weight on its own.

[mitchnick]

28 minutes ago, anthonymm said:

So is 22-23 a good analog year? If so coastal mid atl-sne is screwed.

Assuming it is, they're never exactly the same and small variations can make a big difference with the final results.