PUERTO VALLARTA, Mexico — Hurricane John pummeled Mexico's resort-studded Pacific Coast with wind and rain today, plotting a course that could take its eye close to land before nicking the tip of Baja California.

Authorities in Puerto Vallarta, among Mexico's most-visited resorts, scrambled to prepare emergency shelters while sending patrols to hunt for possible damage from John. But tourists and residents stayed calm even as the powerful hurricane rumbled closer.

John grew into a Category 4 storm Wednesday but later weakened to a Category 3. Still, it had maximum sustained winds of 125 mph and stronger gusts capable of ripping off roofs.

The storm was expected to strengthen today, and Mexico issued hurricane warnings for about 400 miles of coast from the port of Lazaro Cardenas to the fishing and shipping community of San Blas, an area encompassing the bay where Puerto Vallarta is located.

While the center of John was forecast to remain just offshore, hurricane-force winds were expected to begin raking beaches near Puerto Vallarta today, the hurricane center said.

Forecasters said John wasn't likely to affect the United States — cooler Pacific waters tend to diminish the storms before they reach California. Instead, it was expected to skirt close to Mexico's Pacific Coast and head for the Baja California Peninsula by Friday.

Parts of the southern Baja Peninsula, including the resort city of Cabo San Lucas, were also under a hurricane warning.

Meanwhile, a new hurricane formed further west. Hurricane Kristy, with nearly 75 mph wind, was about 690 miles away from John, but forecasters said some interaction was possible. If that happened, Kristy would likely be absorbed by the larger John, forecasters said.