MIAMI -- Hurricane Cosme (KAHS'-may) has strengthened in the Pacific Ocean well off the coast of Mexico.

The hurricane had top sustained winds of 80 mph (130 kph) Tuesday afternoon, and forecasters say the storm will strengthen further in coming hours before it begins to gradually weaken Wednesday and Thursday.

The U.S. National Hurricane Center in Miami says Cosme is centred about 380 miles (615 kilometres) south-southwest of Cabo San Lucas, Mexico, and is moving west-northwest at 17 mph (28 kph).

The centre says the storm is generating large swells that are already affecting parts of Mexico's Pacific coast and soon will be lashing parts of southern Baja California starting Tuesday night. The swells are likely to cause dangerous surf and rip current conditions.

No coastal watches or warnings are in effect.