Where is winter?

1. NAO blocking...where will it set up? Ensembles have been pushing the blocking further west, especially starting with yesterday's runs. But its been generally on the all of the ensembles (both Euro/GEFS) for about a week now. The only difference is it was more pronounced yesterday and it seems to finally be getting closer...at least the big east based block is now inside of 10 days. There is still plenty of reason to be skeptical of the west based blocking idea. HM has brought up the stratospheric state in the North Atlantic going forward in the near-term which would try to inhibit blocking from retrograding westward into the Davis straight region.

2. Aleutian ridge reconfiguration...temporary GOA ridge retrogrades west. This is something that is also becoming a bit more clear with guidance. The temporary GOA ridge (which originally was going to be more of a +PNA, but never got far enough east) that builds for the lakes cutter next week looks to retrograde back and then feed into the Aleutian ridge building poleward again...it temporarily has been beaten down a bit which is contributing to our recent torching in the CONUS. A more poleward Aleutian ridge is going to be key for sustaining arctic intrusion into the CONUS beyond the initial shot behind the Lakes cutter. As the GOA ridge is undergoing this rebuilding, we seem to have another window for a torch in the Dec 13-15 range.

3. Snow. A poleward Aleutian ridge and a -NAO (even if east based) has historically been a very snowy pattern for New England in December. Its not a guarantee but it increases the odds quite a bit. There is a chance we don't cash in because it is impossible to predict the nuances of any given shortwave or synoptic feature, but I think you can at least count on some legit chances as we move into the week of Dec 17-24.

The pattern will look a lot different 10 days from now...of course whether we actually get snow events from it or not will decide whether weenies scream boom or bust.

Here's a look at the GEFS prog for Dec 17-18...the EC ensembles are not quite as enthusiastic about the NAO, but definitely still have it and the overall longwave pattern is similar.