"Some additional weakening is likely while Oscar moves across the mountainous terrain of eastern Cuba, but Oscar is forecast to be a tropical storm when it moves north of Cuba late today and then moves near the southeastern and central Bahamas on Tuesday," the hurricane center said Monday morning.

Tropical Storm Oscar is moving across eastern Cuba after making landfall as a Category 1 hurricane on the island already beleaguered by a massive power outage.

Cuba's electrical grid collapsed Sunday for the fourth time in 48 hours, a major setback in the efforts to restore power to exhausted residents.