Hurricane Vance strengthened to a category two storm as it swirled in the eastern Pacific but remained far from land, US forecasters said.

Vance was packing maximum sustained winds of 105 miles per hour (165 kilometers per hour) early in the morning Monday after it strengthened to a category two storm overnight, the Miami-based National Hurricane Center said.

The storm was located some 505 miles southwest of Manzanillo, Mexico, and was headed northwest at 14 miles per hour, according to the NHC's 0900 GMT bulletin.

"Vance could strengthen a little more today, but a weakening trend is expected to begin tonight with steady to rapid weakening forecast thereafter," it said.

In addition, swells are "likely to cause life-threatening surf and rip current conditions" and affect portions of southwestern Mexico and Baha California Sur in one to two days, NHC said.

Vance is the 20th named storm in the Pacific of the season which ends in November.

In September, Hurricane Odile killed six people and caused $1 billion in damage when it hit Mexico's Baja California peninsula, wreaking havoc in the luxury resort area of Los Cabos.