Meanwhile, CNN reports:
"The ice man cometh. And does so early this year, after a former Pacific typhoon flew up toward the Arctic and rammed the jet stream.
The stream has whipped south, dragging down frigid air from Canada over the northern Plains and Mountain States and the Upper Midwest, according to the National Weather Service.
It is already plunging temperatures below freezing there and will hammer them into the teens and single digits in many places by midweek, even lower in others."
[UPDATE Monday morning 10am: It's down to a still seasonably mild 40˚F (4.4˚C)]