According to the SPC: “The HIGH risk area almost always means a major severe weather outbreak is expected, with great coverage of severe weather and enhanced likelihood of extreme severe (i.e., violent tornadoes or extreme convective wind events over a large area).”

The National Weather Service has survey teams out across Alabama on Sunday surveying damage after many tornadoes are reported to have touched down around the state.

Violent tornadoes ripped through parts of the U.S., wiping out schools and toppling semitractor-trailers in several states.

At least 41 people are dead after a weekend of dynamic storms unleashed tornadoes, blinding dust and wildfires — leaving behind uprooted trees and flattening hundreds of homes and businesses

A series of violent and deadly tornadoes killed at least 40 people across the U.S. this weekend. CBS News correspondent Nicole Valdes reports on the damage from Alabama and CBS News Philadelphia meteorologist Kate Bilo has a look at the forecast.