Gone are the days of temperatures in the 90s as the southern U.S. finally joins the rest of the country in the damp, dreary experience that is the arrival of fall. A ribbon of moisture direct from the tropical Pacific Ocean will team up with an approaching low to dump loads of heavy, much-needed rain on the south in the coming days.

The thing about March is that it lures you in with springlike temperatures, chirping birds, bumbling bees, and just when you start to let down your guard—WHAM!—you get smacked with a winter storm. It happens almost every year, but I am so sorry to say that it's probably going to snow this weekend.

This afternoon's satellite imagery shows an incredible slug of dry air moving across the south and east behind a cold front, bringing beautiful weather to millions of people. In fact, the air is so dry at 10,000 feet above sea level that its humidity is near zero percent in some spots.