Big temperature swings will occur across the country this week. In the East, a 20- to 25-degree warmup will take place Friday and Saturday. At the same time, the West will grow that much colder.

Through the heart of the country, a clash of these air masses later in the week will trigger storm development. On the storm's northern side, it will look and feel like winter with snow falling from the mountains of Idaho across southern Montana and northern Wyoming into the western Dakotas.

From central Wyoming to Minnesota, there will be a cold rain. Some of the rain will be falling on the flood ridden section of the northern Plains. That probably won't make things any worse than what they have been, but the draining process could be slowed even more.

Story by AccuWeather.com Expert Senior Meteorologist John Kocet.