PUERTO VALLARTA, Mexico >> Hurricane Bud strengthened into a major storm tonight as it churned toward an area of beach resorts and small mountain villages on the Pacific coast stretching south from Puerto Vallarta.

Authorities already had canceled school in low-lying communities and began preparing emergency shelters.

A hurricane warning was up for Mexico’s Pacific coast from Manzanillo northwestward to Cabo Corrientes. A hurricane watch and tropical storm warning remained in effect from Punto Telmo to Cabo Corrientes.

Bud’s maximum sustained winds increased to 115 mph late tonight, making it a Category 3 storm on the five-level hurricane scale. The U.S. National Hurricane Center in Miami said gradual weakening was expected to begin by Friday before the center of the storm reached shore.

The storm’s center was predicted to be nearing Mexico’s southwestern coast late Friday.

The hurricane was centered about 170 miles southwest of Manzanillo and moving north-northeast at 10 mph.

The government of Jalisco state prepared hundreds of cots and dozens of heavy vehicles like bulldozers that could be needed to move debris. 

Officials in Puerto Vallarta said they were in close contact with managers of the hundreds of hotels in the city in case tourists needed to move to eight emergency shelters. It said the sea along the city’s famous beachfront was calm, but swimming had been temporarily banned as a precaution.