Scientists said the storm's strength and potential for far-reaching impacts is notable, but its timing isn't unusual.

A multiday outbreak of severe weather — including the potential for strong tornadoes — will begin Friday as a strong storm system barrels across the Lower 48. Parts of the Deep South, Mississippi and Tennessee Valleys and even the East Coast will be impacted by severe thunderstorms,

Weather forecasters warn about a major multiple-day outbreak of severe weather that includes multiple strong tornadoes from the Mississippi Valley to the Gulf Coast, Great Lakes and Atlantic coast through the weekend.