Phil

Did Jim claim 100% certainty?

Front is now crossing the blue ridge..gonna be one heck of a pressure surge. Also noticing some smoke in the air, being carried up here from the fires in the VA/WV ridges. The wind surge should clear the air this evening.

Wind advisory just issued for gusts up to 55mph here. Finally something interesting incoming.

The 00z GFS begins to restrengthen the PV later in the run, which appears to be a direct consequence of the broad Aleutian ridge which shuts down vertical wave activity fluxes from the troposphere into the stratosphere through the NPAC. This would make it difficult to leave the broad Hadley Cell regime in the long run, hence reduce the chances of favorable NPAC blocking and significant winter weather. http://www.atmos.albany.edu/student/hattard/realtime/u_65N_10hpa.png

Now here's an aggregate of the recent "pedestrian" neutral/negative ENSO winters, which were were mostly zonal and lacked Arctic air. Almost opposite. http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/2016-11/D61B6D6F-1511-479A-B067-11B34D67E4BB_zpsge2zfng8.png

From the 00z GFS, can kinda see why the NAO block is important given the poor NPAC state. If you reverse the NAO sign, we get a pattern similar to 2014/15 and even last winter to some extent. http://www.cpc.ncep.noaa.gov/products/predictions/short_range/tools/gifs/500hgt_comp_00gfs814.gif

I guess it depends on what kind of pattern progression you'd prefer and/or enjoy over the next month. The 00z GFS looks like a classically broad, zonal -PNA/Aleutian ridge pattern to me. While that's a nice pattern if you enjoy modestly chilly Pacific air and general troughing/storminess, in the long run it's a pattern that is detrimental for poleward mass/momentum transport and usually trends into a +EPO/GOA vortex regime, while also building a stronger NW Atlantic and/or Canadian ridge which prevents a SE ridge from developing and/or holding. It's not so much that the pattern is bad..it's not. Rather, it's the consequence the pattern has on the waveguide resonances that can be problematic, IMO.

Haven't looked at it yet. One second.

Unfortunately? A Hudson Bay/Greenland vortex destructively interferes with the -PNA cell. This is exactly why the last few winters were failures in the west. Without off-domain supplementation, obtaining sufficient meridional transport across NW North America becomes much more difficult. Ideally, I'd like to see a west-based +WPO/-EPO/-NAO. The elongated, equatorward-biased Aleutian ridge assists in developing a +EPO/strong PV regime, which can be very difficult to break especially towards mid/late winter in a -ENSO state.

I'm sweating with nostalgia. The sound of the wind roaring through bare trees is my favorite aspect of blizzards.

Oh, yeah the operational control run is on board with a modified event of sorts during week 4. I prefer to look at the ensemble mean, which I think offers better predictability at that range. Always risky to rely on a single operational run once out several weeks. Huge swings occur within 10 days, let alone four weeks.

I could see something like that unfolding. I'm confident there'll be a notable -EPO burst sometime in December, but I'm not sure how exactly it'll unfold, and whether or not it'll coincide with a SSW event. February 1989 is the last example of the ideal strat/tropical synchronization.

Are you looking at the same weeklies I am? I see a big NPAC vortex/+WPO/+PNA through the entirety of December. Not that I agree with it.

Bastardi is almost like an east coast version of Jim. Endlessly optimistic regardless of how terrible things look.

Weeklies have the Niño/+PNA/expanded Hadley Cell look, which lasts all the way through December, probably into January verbatim. Weeks 3-6, though day 45: http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/2016-11/D3BF6D96-CED9-453E-9A13-D4F28A50BCA3_zpsscqegttw.png http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/2016-11/7CFA883B-F353-4CB2-8A8A-DC92018AAE67_zpsl5cvewk0.png http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/2016-11/9D57B5D3-B4E5-4592-9B39-7151B320B5B5_zpss4vtsocq.png http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/2016-11/9054ACCD-C491-4E69-A646-5C501D37B4FF_zpsdasaobkp.png http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/2016-11/9A92BFDC-0AE2-4773-B81C-430FF088BA56_zpskxd14nnw.png

Could be a dynamic frontal passage for us on Saturday. I think 50mph winds and snow showers are possible given the vorticity immediately behind the front.

You're a funny dude. I'm more pessimistic about winter here than in the PNW, at least relative to climo. Storm track looks unfavorable, and that's literally all that matters for us.

So, if the equatorial/tropical response to the strawarm is coherent and successful in reigning in the Hadley Cells and lowering the wavenumber, the door opens for something significant in December, and possibly beyond. However, if the wide Hadley Cell background state is just too much to overcome, and the response fails or fails to complete and/or cycle, both December and January could be very problematic over the NPAC. Will have to watch these developments closely. In my opinion, the importance of getting this right cannot be understated.

Despite the aforementioned Hadley Cell issues, there's some good news with regards to the latest stratospheric developments, and I'm starting to think these developments will be crucial to the upcoming winter. The GEFS/EPS members are almost in unanimous agreement with a partial to complete wind reversal @ 60N, at/below 10mb, with a partial to complete destruction of the PV looking increasingly possible. This will assist in not only maintaining high latitude blocking, but will also act to cool the equatorial tropopause/lower stratosphere, which will favor an increase in near equator convection relative to off equator convection. This may act to contract and tighten the Hadley Cells equatorward, and open up the door for a NPAC regime change in December. Usually in cases like this, I'd expect the EPO to tank, and that broad/flat anticyclone south of the Aleutian to disintegrate. Here's latest GEFS forecast (Hannah Attard's site). This is fairly significant. http://www.atmos.albany.edu/student/hattard/realtime/u_65N_10hpa_gefs.png

Jealous. Post pics..need my snow fix ASAP.

That's just the climatological loading pattern for a +EPO. We'd have to start from scratch if that verifies, which would suck given how hard we worked to break up that GOA vortex a few weeks ago.

Eh, the 00z EPS flips to a +PNA during week two, along with both the GGEM ensembles and GFS ensembles.

You could be right. I'm just looking for any excuse to forecast something interesting, and I cannot, for the life of me, find anything interesting on the horizon.

The ECMWF ensemble mean is slower, but still transitions into a +PNA through the week two timeframe. Given where the forcings are headed, it's not something worth denying, IMO. Not like it's permanent or anything.

I haven't given up on winter yet. There's a chance a SSW/complete PV breakdown could put the squeeze on the Hadley Cells, at least indirectly. However, something needs to change...significantly.