With some sleet moving into the north shore, Causeway officials said they were not expecting to close the bridge but that they were monitoring the situation closely.
Temperatures on the bridge decks were not expected to drop below freezing, said Carlton Dufrechou, general manager of the Greater New Orleans Expressway Commission, which operates the Causeway and Huey P. Long bridges.
St. Tammany Parish schools are operating normally, a spokeswoman said.
Highs Thursday are expected to be in the lower 40s, according to the National Weather Service website. No accumulations of precipitation are expected.