Forecasters say one of the key factors driving the weather is an atmospheric river, which is a long band of water vapor that can transport moisture from the tropics to more northern areas.

Many states across the central and eastern United States face wild weather this week, including an atmospheric river and temperature swings. See how in seven maps.

Places like western Maine could see freezing rain, downpours, unseasonably high temperatures and damaging winds — all in the span of a day.