The National Hurricane Center is tracking two weather systems in the Atlantic Ocean – neither of which pose immediate risk to the United States – while Henriette and Ivo wax and wane in the Pacific Ocean.

National Hurricane Center meteorologists warned of life-threatening impacts as the storm is expected to strengthen.

MIAMI — Tropical Storm Erin formed Monday in the eastern tropical Atlantic Ocean, just west of the Cabo Verde Islands, as Hurricane Henriette strengthened in the Pacific Ocean well away from Hawaii, forecasters said.