NEW ORLEANS — From a tiny, vulnerable island off the Louisiana coast to the beaches of the Florida Panhandle, Gulf Coast residents prepared Thursday for a possible hit from Tropical Storm Karen, which threatened to become the first named tropical system to menace the United States this year.
Karen was forecast to lash the northern Gulf Coast over the weekend as a weak hurricane or tropical storm. A hurricane watch was in effect from Grand Isle, La., to west of Destin, Fla. A tropical storm warning was issued for the Louisiana coast from Grand Isle to the mouth of the Pearl River, including the New Orleans area.
In Alabama, safety workers hoisted double red flags at Gulf Shores because of treacherous rip currents ahead of the storm.
‘‘Now is the time for people to review their emergency plans in case conditions worsen,’’ Governor Phil Bryant of Mississippi said.