I might sound like I make light of that snow fall, but after having had opportunity to drive in Southern regions where that has happened, and where it normally doesn't, I know that it's far worse than it looks.
While that may look like light snow and no problem to those of us used to that kind of weather, I know that happening in an area like Arizona it's a huge problem. The roads are not only not built to handle it (concrete is NOT your friend in the cold), but how do you tell a driver of 20+ years, who has never been out in it before, how to drive safely on a sheet of ice?
I may laugh at first, but I know for fact that those conditions would be both super scary and deadly. My last concern in that would be if my truck started or not.
I sincerely hope everyone down there stays safe, and if you are not comfortable driving in that - DON'T, stay home.