Hurricane Henri kept on course early Sunday to crash into a long stretch of northeastern U.S. coastline, as millions on New York’s Long Island and in southern New England braced for flooding, toppled trees and extended power outages.

With the centre of the storm projected to pass just off the eastern tip of Long Island by midday, hurricane warnings extended from coastal Connecticut and Rhode Island to near the old whaling port of New Bedford, Mass., and across the luxurious oceanfront estates of New York’s Hamptons to the summer getaway of Fire Island.

The first thunderstorms bringing what could be up to