Editor's note: This updates with the National Hurricane Center's 8 p.m. EST forecast.

A tropical depression that transformed into Tropical Storm Debby on Saturday prompted Timucuan Ecological and Historic Preserve in Florida to close, while visitors to Dry Tortugas National Park were warned that the bad weather could delay emergency response.

The depression was expected to grow into a hurricane by Monday afternoon as it continued north along the west coast of the Sunshine State. A tropical storm warning was issued Saturday morning for Dry Tortugas, where park staff predicted hazardous marine conditions would last through Sunday.

While Timucuan Ecological and Historic Preserve is on Florida's northeastern coast near the Georgia border, the storm is forecast to swing eastward across the state and reach the park as a tropical storm sometime Monday into Tuesday. Timucuan, which could see 8 inches of rain from the storm, closed at 5 p.m. Friday, along with Fort Caroline National Memorial, Kingsley Plantation, Cedar Point and Theodore Roosevelt Area.

At DeSoto National Memorial south of Tampa, the park's trails, parking lot, and visitor center were to be closed Sunday into Monday.

By Saturday evening the storm was packing 40 mph winds, with higher gusts.

"Strengthening is expected as Debby crosses the Gulf of Mexico, and the system is likely to be at or near hurricane strength when it reaches the Florida Gulf coast," the National Hurricane Center said. 

As the storm moves across Florida and continues north along the Eastern Seaboard, the Hurricane Center predicted it would carry heavy rains with it that could affects parks such as Fort Pulaski National Monument in Georgia, with routinely faces flooding from such storms.

"Tropical Storm Debby is expected to produce rainfall totals of 6 to 12 inches, with maximum rainfall totals up to 18 inches, across portions of Florida and along the Southeast U.S. coast this weekend through Thursday," the agency said. "This rainfall will likely result in areas of considerable flash and urban flooding, with significant river flooding expected."