Hurricane Miriam, churning far off the Mexican coast in the Pacific Ocean, strengthened to a Category 2 storm early Monday, US forecasters said.

The storm located 415 miles (665 kilometers) south southwest of the southern tip of Baja California, now displayed sustained winds of 105 miles (165 kilometers) an hour, the US National Hurricane Center said.

The center said Miriam was likely to strengthen further "during the next day or so" and possibly even become a major hurricane.

But it is then expected to move further north and lose strength once it encounters cold water and winds.