I miss the years that we had a Thanksgiving weekend storm. Those years tended to be great winters, as they set up an early snowpack.

'Fake' cold is certainly a PNW thing. never heard of it until I stumbled upon this board 7 years ago. Its so 'Fake' it's actually real, except its 'Fake'

Euro giveth, Euro taketh away. Thanksgiving system is now pretty much only affecting the NE.

I was referring more to the fact seasonal normals are much warmer out here in early December, such that -20°F departures aren’t really noteworthy in terms of raw temps (averages are roughly the same as early March). As for the PV, what you said can be true (see 1988/89) however it is also complicated. The coldest airmasses develop under arctic highs, where the lack of cloud cover/wind allows uninhibited radiative cooling to space under the polar night. And when the PV is strong/well coupled to the troposphere, it inhibits the development of arctic highs. But you are correct in that when a strong PV is disrupted/destroyed, exceptionally cold airmasses often develop because high pressure/surface cooling surrounds the frigid airmass(es) contained within the TPVs/daughter vortices, insulating them from warm advection/dilution. So the resultant airmasses can be exceptionally cold. And because these TPVs/daughter vortices are now mobile, unchained from the parent PV, they often end up plowing into the middle latitudes, producing extreme cold anomalies wherever they end up.

Hmm. 6 members drop to at least -10C on the 12z GEFS