After a brief and mildly disgusting warm-up, the weather in Washington is about to change dramatically. A big cold front is plowing across the Lower 48 and pushing all of this warm, humid air out into the Atlantic. Here in Washington, the temperature will fall from a high of around 65 today to just 15 degrees Saturday night.

Embedded within that precipitous drop will be a particularly wild decline from around 62 degrees to 42 degrees in just three hours, between 1 and 4 a.m.

Although we’re only expecting scattered snow showers in Washington Saturday, other places along this front are getting a bit more snow. Winter storm warnings are posted from northern Mississippi to Vermont. It’s even snowing in Birmingham, Ala., while Washingtonians are stripping layers to keep cool.

Here’s a look at what temperatures looked like in the Eastern United States Friday morning. See all that blue and purple over in the Midwest? That’s the air that’s heading our way — dry, cold and decidedly more wintry than today.