GEFS still has that Feb 5-7 period as a time where some sort of low moves under the giant Canada ridge/block. Cold air is limited, but it’s got some interest. After that GEFS seems reluctant to get rid of the west coast trough quickly. Seems tied to how quick the Aleutian low is reestablishing.
They are sliding down the east side of the big central Canada ridge. They need to go to our west/south to have any chance, but guidance has shown it enough that it seems possible. Cold air is lacking though, to put it mildly.
If the Euro's right, we pop a +30F above normal day on Friday. GFS keeps the boundary more to the south. When was the last -30F below normal day at any time? Quick glance...the pre-Xmas December 2022 cold shot didn't do it. No days in February 2015 reached that (although almost). January 1994 got a -35F departure at DCA. Anything since then?