Hurricane John strengthened into a dangerous Category 4 storm Wednesday, and forecasters predicted its center would come closer to land during its march up Mexico s Pacific coast, where the storm s outer bands already were hitting tourist resorts with heavy winds and rain. The hurricane had maximum sustained winds of 217 kilometers per hour (kph), and stronger gusts capable of ripping roofs off buildings and causing storm surges of up to 5.5 meters above normal. A hurricane warning covered 500 kilometers of the Mexican coast from Lazaro Cardenas to Cabo Corrientes, the southwestern tip of the bay that holds Puerto Vallarta. The area south of Lazaro Cardenas to Acapulco was under a tropical-storm warning, including the resorts of Ixtapa and Zihuatanejo. Lazaro Cardenas already was being hit with tropical-storm-force winds. The Miami-based National Hurricane Center said hurricane-force winds were likely to begin hitting beaches south of Puerto Vallarta late Wednesday, then come close to hitting land early Thursday. The storm would then edge Los Cabos at the tip of the Baja California Peninsula on Friday before heading out to sea. John was not expected to affect the United States. Forecasters warned the storm could drop up to 20 centimeters of rain along some of Mexico s southern Pacific coast, causing landslides or flooding. Many communities were on alert, but no major problems had been reported. The Mexican army and emergency services were on alert along the coast, and public schools were canceled in Acapulco and surrounding communities. In the resort towns of Ixtapa and Zihuatanejo, authorities closed the port to small boats while city officials set up temporary shelters in case the storm worsened in the area.