2025-2026 ENSO

[Stormchaserchuck1]

Uh oh. raindance's post got the most likes in this thread. Be on alert for the opposite to happen. 

[donsutherland1]

17 hours ago, MJO812 said:

DT

Neutral-cool winters offer a mixed picture. There have been some good ones, one great one (the highly popular 2013-14), one horrible one, since 1980. 1980-81, 1981-82, 1989-1990, 2001-02, 2012-13, 2013-14, and 2016-17.

By late fall, there could be stronger hints. The coefficient of determination for the WPO begins to ramp up in November. A predominantly negative WPO is a good sign for the winter; a predominantly positive one is not. 

Finally, based on subsequent research, the rapid buildup of snow cover in Siberia is not a good thing, if one is looking for a lot of Atlantic blocking. This research has suggested that a higher Siberian Snow Advance Index (SAI) is correlated with a positive AO. It also notes that the early inverse relationship found by Cohen et al., was an exception, not a rule. 

Excerpts:

The running decadal correlations between the SAI_OCT and AO and SAI_NOV and AO are shown in Fig. 7d and e, respectively. In the former, there are significantly more positive than negative values (Table 3), suggesting that the period of strong positive (negative as defined here) correlations that occurred in the 1990s and 2000s, as described by Cohen and Jones (2011), was a rather exceptional event, as previously noted by Peings et al. (2013). Indeed, the frequency of decades with significant SCA_OCT–AO correlations of either sign are not significant. In addition to the recent period in the 2000s, Fig. 7d reveals a period of significant negative correlations centred in the 1840s, also present in the 21-year data (Fig. S4d). Finally, the ERA5 data reveal that the recent period of the statistically significant negative relationship between SAI_OCT and the AO has ended: the most recent decades have positive r values. 

 

[SnowGoose69]

19 hours ago, MJO812 said:

DT

The NAO thing does not seem to hold much weight in the last 30 years.  We have had quite a few very negative Octobers and most of those winters ended up +, obviously most winters have been + so many positive Octobers had positive NAO winters too.  The most positive thing so far continues to be the NATL SST anomalies

 

 

 

[snowman19]

13 minutes ago, SnowGoose69 said:

The NAO thing does not seem to hold much weight in the last 30 years.  We have had quite a few very negative Octobers and most of those winters ended up +, obviously most winters have been + so many positive Octobers had positive NAO winters too.  The most positive thing so far continues to be the NATL SST anomalies
 
 
 

As far as the NAO, the New Foundland warm pool has formed again, as was already mentioned here. I think this winter is going to be highly dependent on the PAC again (goes without saying I know). The common theme on the seasonal models is the Aleutian ridge….does it go poleward or flat most of the winter? A -PDO is a given at this point, but how negative?

[snowman19]

[George001]

On 10/12/2025 at 4:09 PM, MJO812 said:

Lower? Thats bold since the LA Nina isnt even going to be strong . I would go higher for both .  Snow cover up north looks good. 

Having a weak la Nina to neutral enso is great for Philly and NYC. This has a chance to be the best winter in years.

Agree. We are already seeing some promising signs with a transition to a wetter pattern, which did not happen until Feb last year. Weak east based Nina, early northern snow cover build up, the early signs look pretty good. The PDO is negative, but it’s less negative than last year (-2.4 September 2025 vs -3.5 September 2024). 

[LakePaste25]

i agree with webb’s take. i would lean strongly to a pattern similar to last winter. several peer-review studies, such as liang et al. (https://journals.ametsoc.org/view/journals/clim/30/22/jcli-d-17-0149.1.xml) link a strong indo-pacific warm pool to downstream western us/goa ridging, sometimes even independent of the enso state, especially if it is weak. 

[LakePaste25]

1 hour ago, snowman19 said:

 

a pattern similar to last winter but with more -pna tendancies would be great. while it was fine here in the lake effect zones, there wasn’t much synoptic. i don’t think most here would complain about a more active pattern even if it brought more periods of warmth 

[snowman19]

20 minutes ago, LakePaste25 said:

a pattern similar to last winter but with more -pna tendancies would be great. while it was fine here in the lake effect zones, there wasn’t much synoptic. i don’t think most here would complain about a more active pattern even if it brought more periods of warmth 

The -PNA tendency is alluded to in the follow up tweet. 2nd year Niña would support it: 

 

 

 

 

[bluewave]

On 10/13/2025 at 12:38 PM, 40/70 Benchmark said:

No, the pattern has sucked...not arguing that. Bu no luck at all....going to have to disagree, as I often will when anyone speaks in absolutes, at least at this latitude. 

I had 42.5" in 2021-2022....a good 20" below my longer term average.

I think that we are both saying the same thing in our own way. The larger pattern since 2018-2019 has been a function of how dominant the Northern Stream of the Pacific Jet has been. But the smaller features in that larger pattern can vary according to location.

Unfortunately, the best snowfall axis lined up from ACY to Boston in 21-22. But I would still take another winter month like January 22 even if the best axis of snowfall isn’t right in my area.

One benefit of living at your latitude is that you can still get over 40” even if you are 20” below your longer term average. 
 

[donsutherland1]

On 10/14/2025 at 3:04 PM, snowman19 said:

This is AFTER yesterday’s nor’easter. Didn’t even make a dent in the long term drought. The staggering dryness since late July continues. Soil moisture is just as abysmal. So much for BAMWX’s hype back in September that the MJO was going to initiate some crazy wet pattern in the east in October along with possible landfalling tropical systems…..
 

Exceptional events are low probability events. One can't continually call for low probability events and expect anything but a low probability of verification.

Unfortunately, social media is populated by sites and accounts that seek clicks and attention, many of which have little or no understanding of model limitations, local/regional climatology, what is an extreme solution/outlier, the general nature of outliers, etc. That's a big problem for the weather community, as credible forecasters are drowned out by the noise and the credibility of the community is undercut when the extreme ideas typically don't verify. But, at least for now, social media is the "Wild West" of forecasting with no barriers to entry and no screening for quality.

 

[FPizz]

7 minutes ago, donsutherland1 said:

Exceptional events are low probability events. One can't continually call for low probability events and expect anything but a low probability of verification.

Unfortunately, social media is populated by sites and accounts that seek clicks and attention, many of which have little or no understanding of model limitations, local/regional climatology, what is an extreme solution/outlier, the general nature of outliers, etc. That's a big problem for the weather community, as credible forecasters are drowned out by the noise and the credibility of the community is undercut when the extreme ideas typically don't verify. But, at least for now, social media is the "Wild West" of forecasting with no barriers to entry and no screening for quality.

 

Every source hyped the nor'easter up.  It wasnt limited to what you are posting about here.  I get where you are coming from, but 100% legitimate sources did the same in this case. Some will even argue it did verify if you lived on the coast or long Island, but the hype was originally for a more widespread storm.

[donsutherland1]

1 hour ago, FPizz said:

Every source hyped the nor'easter up.  It wasnt limited to what you are posting about here.  I get where you are coming from, but 100% legitimate sources did the same in this case. Some will even argue it did verify if you lived on the coast or long Island, but the hype was originally for a more widespread storm.

I agree that it was overplayed.

[Daniel Boone]

8 hours ago, snowman19 said:

As far as the NAO, the New Foundland warm pool has formed again, as was already mentioned here. I think this winter is going to be highly dependent on the PAC again (goes without saying I know). The common theme on the seasonal models is the Aleutian ridge….does it go poleward or flat most of the winter? A -PDO is a given at this point, but how negative?

Agree. That favors a +NAO as most here know. If something shakes up that area and it cools drastically then things could be different.

[raindancewx]

I've been quite happy seeing the extra moisture this October. A lot of big systems (Lows) are forecast by NE Asia for a while, that's typically consistent with big systems moving through the SW at a 17-21 lead time this time of year. So I do see some support already for an active November. That's implied to some extent with the ACE to ABQ cold day correlation as well. 

I could easily be completely wrong about the winter, but its hard to see a warm winter nationally - I could see it regionally (SE/SW, or both). Serious question - I haven't looked - if you did a difference in proportions test for seasons without a US hurricane hit v. with a US hurricane hit, aren't the seasons without a hurricane hit far colder, or more frequently colder at least? I can't think of many winters following no US hurricane landfall in the US that are very warm, and consistently so.

[Mercurial]

7 hours ago, LakePaste25 said:

i agree with webb’s take. i would lean strongly to a pattern similar to last winter. several peer-review studies, such as liang et al. (https://journals.ametsoc.org/view/journals/clim/30/22/jcli-d-17-0149.1.xml) link a strong indo-pacific warm pool to downstream western us/goa ridging, sometimes even independent of the enso state, especially if it is weak. 

DT says La Nina isn't going to be a major factor this winter, though.

[MJO812]

59 minutes ago, Mercurial said:

DT says La Nina isn't going to be a major factor this winter, though.

It doesn't look like it will be. 

[GaWx]

4 hours ago, raindancewx said:

Serious question - I haven't looked - if you did a difference in proportions test for seasons without a US hurricane hit v. with a US hurricane hit, aren't the seasons without a hurricane hit far colder, or more frequently colder at least? I can't think of many winters following no US hurricane landfall in the US that are very warm, and consistently so.

 The answer is no. Winters following no Conus H hit seasons haven’t been far colder on average and not even frequently colder. First of all, keep this in mind: since 1851 there have been 34 (20%) seasons with no Conus H impact on record. Of these 34, there were only 6 during La Niña (1872, 1890, 1892, 1973, 2000, and 2010) vs a much higher 15 during El Niño, which is intuitive. So, one needs to keep in mind that winters following no Conus H hit years are biased toward El Niño/away from La Niña.

—————————

Winters since 1950 following no Conus H hit seasons: a mix

2015-6: mild

2013-4: cold

2010-1: cold

2009-10: cold

2006-7: normal

2001-2: mild

2000-1: cold

1994-5: mild

1990-1: mild E; cold W

1982-3: mild

1981-2: cold 

1978-9: cold

1973-4: mild

1963-4: cold

1962-3: cold E, mild W

1951-2: mild E; cold W

Of 16 winters in E half of US, 8 were cold, 7 were mild, and 1 was normal…so no signal

W half of US: 9 cold, 6 mild, 1 normal…ever so slight cold signal in W

Here’s the map for all 16 winters since 1950 combined: near normal nationwide/no cold signal at all:

—————

*Edit: here’s the avg for 10 winters following no Conus H hit seasons 1895-1949: actually leaned slightly mild

 

1937-8: normal E; mild W

1931-2: mild E; cold W

1930-1: mixed 

1927-8: mixed

1925-6: cold E; mild W

1922-3: mixed but mainly mild

1914-5: cold

1907-8: mainly mild

1905-6: mixed but mainly mild

1902-3: mixed but mainly cold

[snowman19]

10 hours ago, Daniel Boone said:

Agree. That favors a +NAO as most here know. If something shakes up that area and it cools drastically then things could be different.

Over the last several years the New Foundland warm pool has been a precursor to -NAO linking up with the SE ridge/WAR

[MJO812]

34 minutes ago, snowman19 said:

Over the last several years the New Foundland warm pool has been a precursor to -NAO linking up with the SE ridge/WAR

Nothing wrong with a positive NAO when the other factors are on our side.

[40/70 Benchmark]

18 hours ago, bluewave said:

I think that we are both saying the same thing in our own way. The larger pattern since 2018-2019 has been a function of how dominant the Northern Stream of the Pacific Jet has been. But the smaller features in that larger pattern can vary according to location.

Unfortunately, the best snowfall axis lined up from ACY to Boston in 21-22. But I would still take another winter month like January 22 even if the best axis of snowfall isn’t right in my area.

One benefit of living at your latitude is that you can still get over 40” even if you are 20” below your longer term average. 
 

Yes. The thing about this stretch is that it has been consistently subpar, but I have avoided any bottom-dweller seasons.....just also missed out on the couple of decent ones. It's been a strIng of seasons in the 30s and 40s, save for 2020-2021, which barely snuck above 50".

[40/70 Benchmark]

11 hours ago, Daniel Boone said:

Agree. That favors a +NAO as most here know. If something shakes up that area and it cools drastically then things could be different.

I think a best case for my area is an active, +NAO season with a couple of pronounced periods of major blocking mixed in. I don't really care to have a deeply negative NAO season, which appear to be a thing of the past, anyway.

[40/70 Benchmark]

9 hours ago, MJO812 said:

It doesn't look like it will be. 

The folks laughing at this post should consider that La Nina in and of itself is in fact unlikely to be a major player, regardless of whether the west Pac makes it appear as though it is. Technically Anthony is correct.

[40/70 Benchmark]

17 hours ago, snowman19 said:

The -PNA tendency is alluded to in the follow up tweet. 2nd year Niña would support it: 

 

 

 

 

I think most of this tweet is quite frankly hogwash. I posted the composites a few times and this notion that E QBO supports a flat Aleutian ridge is an utter fabrication. The second year La Nina "rules" are also silly in general. I think the intensity and orientation of cool ENSO is more important that it's place in a sequence. I've seen folks on here point out the flaws with Bamwx, but this guy is far from infallible as well.

[donsutherland1]

26 minutes ago, MJO812 said:

Nothing wrong with a positive NAO when the other factors are on our side.

At least for NYC, the AO is a bigger factor. Red text=% of days e.g., AO-/NAO-; blue text: % of days in the quadrant with measurable snowfall; black text: percentage of total days with measurable snowfall. This is December-February/winter data.

[40/70 Benchmark]

17 hours ago, LakePaste25 said:

i agree with webb’s take. i would lean strongly to a pattern similar to last winter. several peer-review studies, such as liang et al. (https://journals.ametsoc.org/view/journals/clim/30/22/jcli-d-17-0149.1.xml) link a strong indo-pacific warm pool to downstream western us/goa ridging, sometimes even independent of the enso state, especially if it is weak. 

Sign me up for that pattern...while not a KU cookbook, that looks ripe for ample overunning and redevelopment with cold loaded in se Canada.

17 hours ago, LakePaste25 said:

a pattern similar to last winter but with more -pna tendancies would be great. while it was fine here in the lake effect zones, there wasn’t much synoptic. i don’t think most here would complain about a more active pattern even if it brought more periods of warmth 

Yes.

[40/70 Benchmark]

2 minutes ago, donsutherland1 said:

At least for NYC, the AO is a bigger factor. Red text=% of days e.g., AO-/NAO-; blue text: % of days in the quadrant with measurable snowfall; black text: percentage of total days with measurable snowfall. This is December-February/winter data.

Yea, AO and EPO are non-starters if they are hostile. NAO is icing on the cake and more of an insurance element against "what could go wrong".

[40/70 Benchmark]

10 hours ago, raindancewx said:

I've been quite happy seeing the extra moisture this October. A lot of big systems (Lows) are forecast by NE Asia for a while, that's typically consistent with big systems moving through the SW at a 17-21 lead time this time of year. So I do see some support already for an active November. That's implied to some extent with the ACE to ABQ cold day correlation as well. 

I could easily be completely wrong about the winter, but its hard to see a warm winter nationally - I could see it regionally (SE/SW, or both). Serious question - I haven't looked - if you did a difference in proportions test for seasons without a US hurricane hit v. with a US hurricane hit, aren't the seasons without a hurricane hit far colder, or more frequently colder at least? I can't think of many winters following no US hurricane landfall in the US that are very warm, and consistently so.

Yea, I don't see much of an argument for an exceedingly warm season...obviously the CC elephant in the room should provide the impetus for pause before going exceedningly cold, but most should  have a fighting chance this year.

[bluewave]

17 hours ago, LakePaste25 said:

a pattern similar to last winter but with more -pna tendancies would be great. while it was fine here in the lake effect zones, there wasn’t much synoptic. i don’t think most here would complain about a more active pattern even if it brought more periods of warmth 

The lake effect zones have been the place to be with the shift in the storm track west of the Apps in recent years. Plus the warmer lake temperatures are helping boost your snowfall totals.

But areas to the east of the storm tracks have seen a steep decline in snowfall. The Apps runner snowstorm which was prolific from the 60s to 90s has been missing. State College has seen a large snowfall decline since the 60s while your near the lakes area has seen a general increase.

[Terpeast]

1 hour ago, donsutherland1 said:

At least for NYC, the AO is a bigger factor. Red text=% of days e.g., AO-/NAO-; blue text: % of days in the quadrant with measurable snowfall; black text: percentage of total days with measurable snowfall. This is December-February/winter data.

Did you make this chart yourself? This is really instructive. Have you by any chance made one for KDCA as well? I suspect that would be even more tilted in favor of -AO.