A stalled series of storm systems is set to slam parts of the Mid-South and Ohio Valley through Sunday with severe thunderstorms, tornadoes, and potentially "catastrophic" flooding.

Threat level: The National Weather Service is predicting a "high risk" of excessive rainfall in parts of Arkansas and Missouri on Friday, with a broader "moderate risk" area extending from northeast Texas to southern Illinois.

  • The high-risk region shifts little, slightly to the north and east, on Saturday. A fire hose of moisture flowing off unusually warm waters in the Caribbean and Gulf Coast will be funneled along a cold front that is barely moving east.