Imagine if you will that you live in Elko, NV, which is now fully enveloped in the cold, post-frontal air. The temperature today is 41ºF colder than it was yesterday at this time.
The front just recently pushed into the Salt Lake Valley, bringing with it some dusty northwesterly flow and pungent "lake stink." As of 1230 MDT, temperatures are still in the mid 60s in Salt Lake, but much colder air lies upstream. Temperatures are below 50ºF along the Utah-Nevada border.
Yesterday's maximum temperature at KSLC was 98ºF at 1535 MDT. Any bets for the one-day temperature change between yesterday and today at that time? Looks like a 40+ºF change is a real possibility.