Severe weather and flash flooding continue to threaten much of the central and eastern U.S. on Thursday, disrupting Americans' travel plans.

After days of stormy conditions largely in the central United States drove power outages and led to at least three deaths, multiple additional days of back-to-back storms are expected in the region. Severe thunderstorms,

There are two main types of flooding. Normal river flooding usually happens in the spring with snowmelt. Flash flooding is when there are high levels of water flowing through a normally dry area.