Tropical Storm Fabio is strengthening in the Pacific and could become a hurricane but is expected to stay well offshore of Mexico.

The U.S. National Hurricane Center in Miami says the new storm's maximum sustained winds were 50 mph at 5 p.m. EDT Thursday.

Fabio's center is about 425 miles south-southwest of Manzanillo, Mexico, and is moving west at 10 mph.

Farther out at sea, Hurricane Emilia weakened over cool waters as its maximum sustained winds dropped to 105 mph, making it a Category 2 storm.

Emilia is centered about 980 miles southwest of the southern tip of Mexico's Baja California and is moving west at 12 mph.