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: