Mayor Bill de Blasio is urging New Yorkers to prepare for the worst as a major storm threatens to blanket the city with more than two feet of snow.

At a news conference on Sunday, de Blasio said it “could be one of the top two or three largest storms in the history of the city.”

The National Weather Service has a blizzard warning in effect for the New York and Boston areas starting Monday night. Forecasters say a massive storm could drop two to three feet of snow from northern New Jersey to southern Connecticut.

The mayor urged New Yorkers to avoid the Monday evening rush hour and to get home as early as possible. He said schools would be open Monday, but that after-school activities have been canceled.

Alternate side parking has been suspended for Monday.

(AP)