BlizzardWx

Interesting how different this summer has been than some of those years. Obviously you have to adjust the mean anomaly up or down for the various years, but where we had ridge-trough-ridge across the conus (this year), both of these other years were the opposite. Polar domain also looks quite different. Not sure what it means or not, but in my mind its the idea that the ACE correlation isn't great because there are many paths to low or high ACE.

Ultimately I think this is a good example of what @40/70 Benchmarkis always talking about and why we have to resist the urge to view things in isolation. I view the winter pattern like the mosaic of ripples on a pond if you were to throw a few stones in. Each stone could be a different index or measure of forcing. It's not the individual ripples that matter, it's the collection and how they interact that matters. Some years ENSO is the biggest stone, but maybe not in the case of 23-24. Similarly, when I look at the global SSTA's this year, there is no doubt that the North Pacific is going to be our biggest "stone". But even then we have to be careful to not simplify it to a "hot north pacific". The relative location of the max anomalies and gradients matters. And you can't pick that kind of stuff up from a blanket index. That is why although in theory you could say well we have a big negative pdo, enso, and iod so that means such and such, but it's the details within these zones that may make or break winter.

Interesting that the ECMWF weeklies seem to want to develop a GOA low for mid September and October. If that did happen I imagine we'd start to erase a lot of those warm anomalies south of Alaska like last year.

Nighttime lows holding up temperatures here too. This summer: June High/Low: -0.3F / +1.9F July High/Low: -1.2 F / +3.2 F August High/Low: -3.6F / +0.9F I don't think this is too unusual around here either. Lows are being held up by higher moisture levels.

Oh don't get me wrong, I am not saying there is no comparison. There are several reasons why it could be an analog, I was just trying to note that there are many serious differences from a SSTA perspective that should not be glossed over.

I know several consider last winter to be a top analog, but there really has been a lot of change in the SSTA pattern in just about every basin. The observed pattern also feels very different. We had a high of just 70 F today in Tulsa for the 5th coldest on record, which is on top of a cool and extremely wet summer...very different from last year at least at this juncture.

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.

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.

And like any relationship, it can always be overwhelmed by other factors working against it. I think @bluewave may have had the right idea that as teleconnections change with cc, potential connections like this become less reliable.

The only case I've seen that sort of supported it was in the Pacific in maybe 2014-2015 or so. I recall numerous fall typhoons directly helped to pump up a big western USA block that just kind of persisted most of the fall and winter after it set up. Of course, maybe that was going to happen anyway, but at least the connection was more obvious. To me, if the ACE connection is real, it would probably matter where the ACE is accumulating, as it could be indicative of something larger in the background state. That would mean its a symptom but not a cause. I could at least entertain that.

What is the reasoning for why ACE would matter so much for the winter pattern? It's kind of hard to accept at face value that any heat transfer now would matter say 3-6 months later. It also seems like the ACE calculation is flawed since it doesn't take storm size into account. A little storm like this is treated the same as a much broader one right?

I wonder if this correlation changes at all with the strength of the ENSO event. It's going to be a fairly weak event in terms of ENSO, so perhaps the correlation won't be as reliable. The weakest example you showed for 16-17 didn't match the expected pattern. I guess it may depend on what is driving it. I suppose the -PDO implies the atmosphere thinks its la nina regardless of ENSO, at least to some degree.

Looks like the odds for an upper end arctic outbreak into my area in the southern Plains will be elevated once again this year. It doesn't always work out to get a lot of snow with those big hits, but that is a look that favors 1 or 2 significant cold events here.

Yeah I can see those. Thanks!

For some reason I can never see your images. It's always just something like "3aa-14.png". Does anybody else have this problem? I don't comment much, but I always appreciate reading all your comments as well as everyone else's.