Puerto Vallarta, Mexico ? Hurricane John lashed tourist resorts with heavy winds and rain Wednesday as the dangerous storm marched up Mexico’s Pacific coast, and forecasters predicted its center would brush close to land before nicking the tip of Baja California and heading out to sea.

The Category 4 hurricane could dump up to a foot of rain along parts of Mexico’s southern coast, causing landslides or flooding, meteorologists warned. The hurricane had maximum sustained winds of 135 mph and stronger gusts capable of ripping roofs off buildings and causing storm surges of up to 18 feet above normal. It was expected to strengthen somewhat throughout the night Wednesday.

John was not expected to affect the United States – cooler Pacific waters tend to diminish the storms before they reach California. But a hurricane warning covered a more than 300-mile stretch of the Mexican coastline from the port city of Lazaro Cardenas north to Cabo Corrientes, the southwestern tip of the bay that holds Puerto Vallarta.

The government also issued a hurricane watch for portions of the southern Baja Peninsula, from La Paz south on the east coast and from Sante Fe south on the west coast, an area which includes the resort city of Cabo San Lucas.

So far, the most damaging winds have remained offshore, and only tropical storm-force winds have hit the coast.

Skies were clear and tourists relaxed on the beach in Puerto Vallarta. But officials postponed the arrival of a Carnival cruise chip and prohibited customary tours of the bay.

Strong waves pound the shore of the resort city of Acapulco, Mexico. Hurricane John strengthened into a dangerous, Category 4 storm Wednesday and forecasters predicted its center would come closer to land along Mexico's Pacific coast, where its outer bands already were hitting tourist resorts with heavy winds and rain.

Aniko Simon, 37, a tourist from Toronto, gathered with her family on the beach. She said she hadn’t been aware there was a hurricane in the area until last night, when she saw a television news report. The family plans to return home Friday as scheduled.

William Rousseau, a tourist from Oregon vacationing with his family in Puerto Vallarta, said hotel officials warned about the hurricane “but we’re calm because they say it’s not going to hit this city.”

“We’re continuing to enjoy the city,” he said. “They just asked us not to go into the ocean or on any bay tours.”

Other tourists could be seen strolling through the streets visiting craft shops and eating in restaurants.

In Cabo San Lucas on the Baja Peninsula, there was more urgency, with fishermen and port authorities rushing to prepare for the hurricane and local authorities setting up shelters.

“We are preparing shelters for the evacuation of civilians, if that becomes necessary,” said Luis Armando Diaz, mayor of Los Cabos, situated on Baja’s southern tip. “According to the information we have, the storm is coming right toward Los Cabos.”