CEDAR KEY, Fla. — Florida’s Gulf coast braced Thursday for a hit from Tropical Storm Hermine, which forecasters said could make landfall as a hurricane.

A hurricane warning was in effect for Florida’s Big Bend from the Suwannee River to Mexico Beach. And on the East Coast, a tropical storm warning was issued for an area that extended from Marineland, Florida, northward to the South Santee River in South Carolina.

Hermine’s maximum sustained winds Thursday morning were near 65 mph (100 kph). Some strengthening was forecast and the U.S. National Hurricane Center said Hermine was likely to be a Category 1 hurricane when it makes landfall in Florida on Thursday night or early Friday.

As of 8 a.m. EDT Thursday, Hermine was centered about 235 miles (380 kilometers) west-southwest of Tampa, Florida, and was moving north-northeast near 12 mph (19 kph).

Residents in some low-lying communities in Florida were being asked to evacuate Thursday as the storm approached. The Tallahassee Democrat reported that emergency management officials in Franklin County have issued a mandatory evacuation notice for people living on St. George Island, Dog Island, Alligator Point and Bald Point. Residents in other low-lying areas prone to flooding were also being asked to evacuate.

Florida residents in the Big Bend area were getting ready for possible storm surge and heavy rain. In Cedar Key, Jordan Keeton said workers started placing sandbags Wednesday to protect his 83 West restaurant from possible flooding. He said he was mostly worried about the new equipment he’d recently purchased for the waterfront restaurant.

“This building right here is pretty safe and pretty strong so I think it will be all right,” Keeton said. “Pretty much the new equipment is my primary concern.”