Left exit and right entrance regions, where upper level flow diverges. Conservation of mass and surface boundary dictates that air must lift to replace the diverging flow.
Idk, warm nose all the way up to the M/D line. Week later we would still have mixed. End of month would have been snowier. It was just not a cold system this time.
Just checked all the mesos forecasts of 2m temp at valid 00z 12/2 (which is right now), and they are all too warm. The closest one is fv3
Doesn’t mean anything about upstairs, but surface is colder than forecast.