In New York, Mayor Michael Bloomberg ordered police to use their patrol car loudspeakers to warn vulnerable residents about evacuating, even as forecasters said Wednesday's storm could be weaker than expected.
Atlantic County, in the southern part of New Jersey, activated its emergency operations center and told residents to restock their emergency supplies.
Storm surges along the coasts of New Jersey and New York were expected to reach perhaps 3 feet, only half to a third of what Hurricane Sandy caused last week. While that should produce only minor flooding, it will still likely cause some erosion problems along the Jersey coast and the shores of Long Island, where Sandy destroyed some protective dunes.
Some airlines announced they're canceling flights into and out of the Northeast ahead of this next storm. This comes a week after 20,000 flights were canceled because of Superstorm Sandy.
More than 1,300 U.S. flights were canceled Wednesday, according to FlightStats.com. United grounded about 500 flights starting at 3 p.m. ET out of the New York area's three major airports.
Twenty-one flights out of Los Angeles International Airport to John F. Kennedy and Newark airports were scrapped, leaving some travelers stranded in the terminal all day. Many airlines are allowing travelers to change their plans without penalty.
The Associated Press contributed to this report.