What a great sounding this morning from the Salt Lake City International Airport (KSLC). There's a low-level inversion of 11ºC between the surface and about 830 mb. Incredible!
Given the shallow nature of the cold air, it's interesting to compare the temperature traces at KSLC (4226 ft) and the William Browning Building at the University of Utah (WBB, 4806 ft). Despite being a bit higher in elevation, the high temperature at WBB yesterday was a smidge higher than at KSLC. This is not unusual during an inversion.
But what is really interesting is the temperature evolution at night, when there are wild temperature fluctuations (about 10ºF in magnitude) at WBB. WBB sits right near the top of the inversion where waves and turbulence cause the cold air to move up and down. This yields large fluctuations in temperature. If you envision the cold pool in the valley as water, then the WBB sits right on the water line and it gets cold when a wave sloshes on the beach and warm when it retreats.
In contrast, KSLC is on the valley floor and deep in the cold pool. You don't see such behavior there and the temperature is relatively steady overnight.