A building ridge aloft is a good set-up for strong valley based inversions in the winter in Interior Alaska, as temperatures this Saturday morning illustrate. Here's the temperature trace from the lowest 1000 meters from the early morning sounding at the Fairbanks Airport.
As usual, most of the vertical temperature gradient is in the lowest 100 meter (-29C to -15C). The pressure gradient is increasing across the area this morning, with 10 to 20 mph east winds blowing at elevation, and the wind is starting to reach the valley floor in places. Surface temperatures from Fairbanks-land from 7 to 8am AST Saturday show a similar spread:
Goldstream Creek: -31F
Fort Wainwright RAWS: -30F
Woodsmoke CWOP: -30F (near North Pole)
Eielson AFB: -28F
UAF West Ridge -14F
Fairbanks Airport -15F (winds NE 5 mph)
Fort Wainwright Airport: -19F
Wickersham Dome: +10F (2200' MSL)
Caribou Peak RAWS: +10F (2500' MSL)
Keystone Ridge: +12F (1600' MSL)
Fox Ridge (CWOP)" +14F (2100' MSL)
A 40 degree spread is pretty impressive even by Fairbanks standards. Being two months past winter solstice, clear skies, and some wind I'd expect temperatures will rise dramatically at valley elevations today.