A winter storm watch is posted from Washington, D.C., to New York City.

The western storm finally left the West and is moving into the Midwest Saturday and into the Northeast Sunday night into Monday.

More than 15 inches of snow fell in parts of coastal California and up to 107 inches of snow fell in the Sierra Nevada mountains. That’s 9 feet of snow, in just a few days.

Heavy rain caused mudslides that buried homes, closed roads and prompted evacuations. In the mountains, several interstates had to be shut down for a time due to the heavy snow.

As the storm moves east, 21 states — from the Dakotas to North Carolina — are on alert for heavy snow and a lingering Arctic blast.

A winter storm warning has been issued for Chicago, where heavy snow is expected from Saturday afternoon into Sunday.

A winter storm watch has been issued for Washington, D.C., for Sunday and Philadelphia and New York City for Monday.

Chicago will see 5 to 9 inches of snow due to the storm, while Washington, D.C., will see 4 to 8, Philadelphia will see 5 to 11. New York City will see 6 to 10 inches. These totals may change over the weekend.