Forecasters warned swimmers that many U.S. East Coast beaches will remain dangerous this weekend, as Erin became a post-tropical storm and moved from the U.S.

Forecasters are tracking the potential impact of Erin, which underwent a 'remarkable' 24-hour transition from a tropical storm to a 160mph Category 5 'monster' last weekend.

Dangerous surf conditions and rip currents remain a threat at beaches along much of the East Coast.

Forecasters warned swimmers that many U.S. East Coast beaches will remain dangerous this weekend, as Erin became a post-tropical storm and moved from the U.S.