On Thursday, the storm was bringing heavy snow and strong winds to the Sierra Nevada and heavy rainfall over parts of coastal southern California.

Violent tornadoes ripped through parts of the U.S., wiping out schools and toppling semitractor-trailers in several states, part of a monster storm that killed at least 18 people as more severe weather was expected late Saturday.

Dozens of tornadoes are reported from thunderstorms that lit up the radar from Wisconsin to Mississippi in the early hours Saturday.