Phil

Tossing the stronger ENSOs leaves 1995 and 2008, both of which were -ENSO but different in a number of ways. Obviously we're not following 1949/50 or 1965/66.

That +EPO also promotes a momentum transfer unfavorable for maintaining a SE ridge. The broad/flat NPAC anticyclone/+EPO under a perturbed/semi-perturbed NAM will naturally want to put the trough in the central/eastern US with time. Absolutely have to have that -EPO/amplified anticyclone into the GOA/western Arctic. Without that, there'll be big problems in the long run.

The problem with the 12z ECMWF is (again) that mature cyclonic wave over Alaska (+EPO), and the corresponding lack of upstream/NPAC amplification. If that verifies, you can absolutely forget about any significant winter weather in the near future. There'd be no chance. Downstream dynamics aren't the problem here. Upstream dynamics are the problem.

Wrong. That Greenland block is what's keeping the troughing in the west-central US/Canada via constructive interference with the -PNA circulation. How is this not obvious? Have we all forgotten what the last several winters have had in common? A Hudson Bay Vortex, which destructively interferes with the -PNA circulation (and constructively interferes with the +PNA/TNA circulation).

A few fractions of a degree are meaningless here. There's not much of any ENSO signal right now, and this doesn't look to change.

Yeah, also the 30 day SOI has been negative for almost a full month now. There's essentially no ENSO signal right now. https://www.longpaddock.qld.gov.au/seasonalclimateoutlook/southernoscillationindex/30daysoivalues/

Sure, but I'm not talking about "cold". I'm referring to the mature cyclonic wave situated there..that's never a good thing and seldom precedes a blast. Would like to see that wave (or technically a pair of waves) situated farther E/SE by a few hundred miles at least.

Not a fan of the 00z ECMWF. That anticyclone is overly broad and is in the process of overturning, which will allow the SE ridge to pancake shortly thereafter.

That Alaskan troughing is a problem, actually. Need to see more ridge amplification there.

Something like that, lol.

True, volcanic stratosphere to blame there. I'm just referring to the tropical forcing components. Doesn't have to be an exact match in time, either, just similar structurally speaking.

I think he switched his screen name or something.

Tropical forcings have been emulating 1983/84 almost perfectly, regardless of the volcanic strat that year. However January 1984 turned out, I'd lean towards something similar to that (forcing wise), except with more polar blocking/NAO and a higher H/W ratio.

Poleward mass/momentum fluxes/equatorward eddy flux, strong NAMT/EAMT ratio. Fantasyland stuff here, but would eventually result in a classic -EPO/NPAC wavebreak that'd propagate poleward. Hard to dislike the underlying tendencies on this one, despite some minor flaws.

Haha. I just look for a supplementary wavebreaking regime, and this run happens to deliver in that regard. Was obvious by hr162. Without that, nothing happens.

Big difference this run: No Hudson Bay/NAO vortex. Whether or not the polar front makes it south of northern WA in clown land, I think this run makes an example of the necessity of downstream constructive interference. In other words, upstream anticyclonic breaking in lockstep with the -NAO.

This might be more than just a warning shot in clown range, assuming this progression continues. Big -NAMT..going to retrograde that ridge into the sweet spot sometime in the 11-15.

Going to attempt a retrogression after day 10.

Looks like a scenario where the NAO block will try to fuse with the GOA/EPO block. Probably results in a backdoor/offshore flow event or something.

Amazing how fickle these things can be..a simple missed EPF heartbeat or unfavorable tropospheric loading pattern can just demolish a perfect setup for an early PV destruction. http://www.atmos.albany.edu/student/hattard/realtime/u_65N_10hpa.png

No, but at least a winter delay (taken verbatim, which isn't a given). Worst case (somewhat less likely) would be a return to the dominant Hudson Bay Vortex/+NAO that we've seen in recent winters, which, much like a +EPO/-PNA regime, can be very much self reinforcing/difficult to dislodge.

Yup, flat Aleutian ridge --> shuts down WAFz forcing into strat/polar domain from NPAC --> consolidates +PV/+NAO. Amazing modeling fail w/ the stratosphere lately..the PV now looks to recover and rapidly strengthen into December.

Yeah, a poleward displacement of mass above 55N and 110/160W seems to be a requirement, looking at events since 1979. There are a number of ways to achieve that, but they all require a certain tropical/polar synchronization.

That was my opinion as well, alluding to my point about a favorable PNA (by itself) being insufficient for the lowlands to score. But apparently we're all dry humping 07/08 now, so what the heck do I know?