Looking closely at the GFS/ECMWF and honestly the pattern isn't that far from going from stormy/AR and Mt. Snow, to significant Alaskan blocking and arctic air digging towards us. That 00z GFS/ECMWF was incredibly dynamic just through Day 7 alone both spinning up a 950mb low! That trough means business with the polar air colliding with mild southwesterlies and powerful jet segment rounding the base of the trough. If that were to trend further east and digging a bit more look out!!!!
Night Shift 6z GFS in 2 hours 10 minutes