BlizzardWx

00z ECMWF at 50 hPa has a full PV split with 3 daughter vortices, one right over the US. That'll help heading into December.

These aren't very polished, but for fun here is the GFS, GEFS, and CMCE 10 hPa zonal mean wind for the next 16 days. CMCE is on board with the SSW in the mean, GEFS is lagging.

Might be an ice storm pattern for my part of the world with cold air under cutting mild SW flow aloft

I was coming on here to mention this. It's showing up in the GEFS mean too.

Over my way it began when it stopped for you all. Snowiest February on record and the Oklahoma state record coldest temperature.

No, it's a daily value. It's gone down a good bit the last little while.

On my page you can plot the daily values for most of the indices anybody cares about. RONI is below -1.2 now. https://weathersigma.com/sst?i=RONI

I've slowly been working on a weather model/ climate index page. I think it's far enough along to share. https://weathersigma.com/sst Within this tab you can select a range of dates to display. I've run it back to the start of 2024 if you want to check past data. Each map has a bunch of index values along the bottom. They don't perfectly agree with other sources but some of that is related to exact methodology, region of choice for the index, data set, and so on. My IOD doesn't run as cold as what I've seen on here, for example. If you find it useful, find errors, or it needs changes, let me know. But I hope it'll be useful. It updates daily like the world climate service site. The 2nd image is an IOD plot, which can be selected near the bottom of the menu.

I saw JB referenced @GaWx on one of his blogs and called him by name. Maybe JB reads all of the hate about himself on here too

The issue still remains why that occurred, but this does make sense otherwise.

I remember last year the mid level PV was often partly to mostly uncoupled from the lower level PV, or maybe it was just much weaker than the mid level vortex. Am I remembering that right? I wonder if there are any hints of that happening again.

FWIW this is exactly what I was talking about in my last post. People need to stop reading into what happened at exactly their house (mesoscale randomness) and assume it means anything in the big picture. That level of precision is noise and does not mean a pattern was good or bad.

I'm not sure exactly how you would do it, but I know I'd like to see more winter outlooks or past winter discussion focusing on snowfall potential rather than what fell at specific points when possible. Maybe another way to look at it would be to say is this objectively a snow producing pattern even if it didn't occur at Central Park (or wherever). If we could remove luck (mesoscale patterns) from more of our analysis I imagine it would be more constructive to discussion of the patterns at hand. I think some of what @donsutherland1 has been showing is kind of a step in that direction. You could in theory score a pattern based on its historical correlation to snowy patterns to say how good a winter should have been regardless of what actually happened at some point. Just a thought.

I do think the pattern coming up will favor slowly moving that warm pool in the central Pacific a bit further east with continued cooling influences east of Japan and along the west coast, at least for the next 2 weeks anyway.

I appreciate your views and everybody else's. I come here to see viewpoints from all angles. I'd say the same thing to you as well as everybody else, please continue to contribute. I value it.

Hopefully time to finally kill the -PDO and MJO 4-6 warm pool with that flip.

True. I do think ridging ends up a bit less amplified than last year, but I still think we see cold get a bit further south than what it has.

EPS weeklies try to bring the GOA trough back by the 20th of this month. But on the other hand they didn't see this GOA ridge until a few days ago. But considering this GOA ridge will probably be a dominant feature this winter I am not surprised to see it poking back up.

That was when one of the worst ice storms for northeast OK occurred. Please no

Definitely unusual as you noted, but does it matter if the forcing is propagating the "wrong" direction? Off hand I am not sure why it necessarily matters directly, but indirectly it implies a weakness in potential analog forecasts.

The more I hear about this SAI index, the more questionable it sounds. But as for the northeast Pacific, I agree it will probably continue to cool given the storm track. It could always reverse later of course, but I see no sign of that through October at least.

Yes, and he says that. But I suppose if September is well above normal it could in theory help October. I don't know, just passing it along basically.

I'm not real big on the Siberian snow cover thing. But Judah Cohen posted this on X saying we are off to a good start and on track to continue.

As most of you probably know, the PDO is the first EOF and explains the greatest amount of variability in the northern Pacific. But there are other modes that matter. I was looking at a paper from Werb and Rudnick in 2023. They showed how historically the PDO accounted for 23% of variance with the 2nd EOF at 13%. But noted how that second EOF in the past decades increased to 18%. It might even be more than that now. But the point I wanted to make is that this 2nd EOF looks a lot like the pattern we have had lately, particularly with the stronger anomalies off of Japan. Obviously a bit mixed given waters are also warm off the west coast. I'd say we have a -EOF 1 (-PDO) combining with a +EOF 2 right now. Has any work looked at the winter effects of this second EOF? It's not the exact same thing as the NPM. We really ought to be paying more attention to it. In a broader sense, the lack of contrast across the Pacific will affect how the -PDO manifests itself compared to the last few winters. It's probably the most widespread warm blob we have seen.

I wonder if this will continue into winter. Any thoughts? I know a lot of our troubles the last ten years have been from too much MJO 4-6. So maybe no real MJO signal would be a plus?