We're still days away from the official start to the 2018 hurricane season in the Atlantic, but the first named storm of the season has arrived, and it forced the closure of Gulf Islands National Seashore.

Alberto, which reached tropical storm status earlier this past weekend, was downgraded to a subtropical storm as it neared the Gulf Coast. At the national seashore, the weakening of the storm had officials slowly reopening parts of the park on Monday.

The Davis Bayou Area was to reopen Monday morning, with the campground there open on a first-come, first-served basis. Reservations for the campground were to resume Tuesday.

West Ship Island was to begin reopening Tuesday, depending upon conditions. Other barrier islands were expected to be opened Tuesday morning, again, depending on conditions.

The National Weather Service was warning that heavy rainfall from the storm could lead to flash flooding across the Florida Panhandle, much of Alabama, and western Georgia through Monday night, and in the western Carolinas and Tennessee on Tuesday.

There also was the possibily of a "hazardous storm surge along portions of the eastern Gulf Coast today," the Weather Service said. Dangerous surf and rip tide conditions were expected to continue in the eastern and northern Gulf Coast areas through Tuesday, it added.