Adding to the story was the post-frontal blowing dust. At Wendover in far western Utah, the post-frontal visibility dropped to as low as 4 miles, likely due to blowing dust. However, at the Salt Lake City International Airport, minimum visibilities reached 1 mile, suggesting that dust emissions from the area surrounding the Great Salt Lake and the west desert contributed.
The dust made the cold front very apparent as it entered the Salt Lake Valley (h/t to @UteWeather for tweeting the image below, taken facing from the U toward downtown Salt Lake City). One can see the classic frontal "nose" to the left of the photo, with friction resulting in a slight forward tilt of the front with height in the lowest one or two hundred meters, above which the front slopes back over the cold air.
The post-frontal air was nasty. PM2.5 concentrations spiked to 120 ug/m3 on campus immediately following frontal passage.
I guess if you're not going to have much snow, weather excitement like this is better than nothing.
Addendum @1235 MDT:
Shortly after writing this post, the PM2.5 at our mountain met lab topped out over 200 ug/m3 (note scale change from graph above).
There's some uncertainty in these measurements, so perhaps we should be cautious about the absolute values. That being said, the air was pretty nasty out there and remains so as I write this at 1235 MDT.