The watch had spanned the area between the Savannah River to South Santee River.
At 5 p.m. EDT, the National Hurricane Center in Miami said the center of Alberto was about 105 miles southeast of Savannah, Ga., and about 130 miles south of Charleston, S.C., with maximum sustained winds of 45 mph and higher gusts. Alberto was moving southwest at 6 mph.
The storm was expected to slow down and drift toward the south Sunday night, and then pick up speed and turn toward the northeast Monday and Tuesday. On its forecast track, the storm was expected to remain off the Georgia and Carolina coasts, forecasters said.
Forecasters cautioned coastal interests from northeastern Florida to the outer banks of North Carolina to monitor the storm's progress.
Dangerous surf condition, including rip currents, may occur through Monday along the northeast Florida, Georgia and South Carolina coasts.
The storm is the first of the Atlantic hurricane season, which begins June 1.