Tropical Storm Olga has formed in the Gulf of Mexico and coastal flooding is possible across portions of the northern Gulf coast, the U.S. National Hurricane Center (NHC) said Friday.

The NHC said that gale-force winds associated with Olga and its remnants should spread over portions of the northern Gulf coast Friday night and Saturday morning. The storm is expected to produce heavy rain across the Central Gulf coast in Louisiana into the Lower Mississippi Valley through Saturday morning.

It warned that a couple of tornadoes are possible through Friday night across southeast portions of Louisiana and Mississippi into southwest Alabama.