40/70 Benchmark

Weak, East-Based La Niña Impact on Extra Tropical Pacific The expectation for both a weaker and east-based La Niña influence during winter 2025-2026 remains consistent with earlier analysis this summer. Note that the behavior of the subsurface during the month of August was anticipated quite well last month, and continues to set the stage for an eastern biased event centered around 120 degrees longitude. Historically speaking, in east-based La Niña winter seasons there is both a high latitude blocking signature and a prevalent poleward Aleutian ridge displaced to the northwest, off of the west coast of the CONUS relative to the central-based and Modoki La Niña composites. These are shared features with the weak La Nina composite, which is similar due to the fact that the majority of east-based events are also weaker cool ENSO episodes . Thus it is not surprising that the composite of the three primary El Niño Modoki Index analogs of 1995, 2017 and 2021 were all centered in the vicinity of 120 West longitude, and 2/3 were weak events; with the 2021-2022 La Nina representing the lone moderate season. Nor is it a shock that the pronounced Aleutian ridging positioned off of the coast and protruding poleward in conjunction with some degree of NAO blocking is also very evident.

Here is +QBO: While it looks like the ridge is a bit more poleward in this composite, I def. don't think it looks flat in the other one. I would say it has more to do with the type/intensity of cool ENSO than it does QBO. Def. more NAO blocking in the Easterly QBO composite.

Here is a composite of seasons since 1950 that I would consider to be cool ENSO and fully Easterly QBO at botht he 30mb and 50mb levels throughout the vast majotiyy of the winter DJFM season....not extremely poleward, but I wouldn't consider that Aleutian ridge to be "flat":

Yea, obviously the point isn't to expect a record winter, but rather we shouldn't be resigned to another dud because the year has been dry thus far.

This is fair....TBH, I struggle to see the connection either, but there is a pattern evident in the composites.

Well, I've showed you the composite, and it simply isn't true. False. Whether it's a coincidence or not, there is also a clear tend in the ACE composites.

Okay, care to acknowledge the other five factors I mentioned?

I don't agree. I can't find on piece of data that argues against it...don't mean it will necessairly work out, but I the point is I see. no reason to bet against it....polar analogs, weak, basin-wide to east-based La Niña, strong E QBO/near solar max, normal to above average ACE.....name it.

I think about 125 ACE and up is considered above normal.....so add another feather in the cap of poleward Aleutian riding this season if that indeed comes to fruition.

Yea, no harm.....happens to all of us. I admire that you put yourself out there.

Oh, Paul Roundy...wow. You're in good hands.

This is what I was saying.

We probably won't indentify it until we see the whites of the snow.

@weathafella

Also, remember...SSTs are part of a feedback, which is the reason for the correlation, but they don't run the show....if the atmosphere begins changing, the sea will not lead the way.

I don't think 2020-2021 was below normal there. 2021-2022 may not have been, either.

They have been for the past several years, and the WPO averaged negative without a NE warm pool to offset in 2021-2022. Anyway, I'm not arguing it's going to make it negative...just prevent it from being extremely positive.

Seasonals have it persisting. Remnant of what triple dip? It wasn't there during those three consecutive La Nina events earlier this decade.

I would feel compelled to go through those seasons and check the QBO/solar states. Its going to be difficult to sustained a storngly +AO early on with a strongly easterly QBO near solar max. 1974 and 1979 appear to be decent QBO matches-

This data set illustrates my point about how crucial the WPO will be. All of these seasons except for 1998, which sucked, had a -WPO. Having a favorable WPO leaves much more margin for error, so hopefully the western warm pool is offset enough by the NE PAC warming so that it isn't so extreme this season. A strongly positive WPO leaves virtually no margin for error around the rest of the hemisphere, so if anything else is significantly unfavorable, then most of us are cooked and upside is near normal.

This data set actually has some nice winters for my area...2004, 1993, 1992 and 1960 were great, very good, great and very good. 1974 and 2016 were respectable. 1979-1980 was my lowest snowfall season ever and 1998 sucked. I think I would take this data set over the other one TBH.

Agreed RE him, but I can't every recall you being on the decent winter train, either...and notice I say "decent winter" as opposed to "cold". It's never cold anymore, but there have been decent winters.

Interesting...a bit of overlap...1993 common denominator. I looked at that season, but ultimately disregarded because there was too much of a warm ENSO flavor to it.

I will say that this is not an unreasonable look, and resembles many of the early composites we have seen...but I don't think it's tweaked enough for CC because no way negative anaomalies will be that expansive in a seasonal mean this day and age.....I would snip away the southern and eastern third of that area.

I always advise taking this guy with a grain of salt, but this is an interesting piece....I consider him like snowman, only on the opposite end of the spectrum. He clearly knows enough to be dangerous, but his data always seems to point in the same direction. https://www.severe-weather.eu/long-range-2/will-north-pacific-ocean-anomaly-bring-cold-winter-2025-2026-united-states-canada-fa/