Hurricane Otis has rapidly intensified into a powerful Category 4 storm as it makes its way towards Mexico's Pacific coast, with landfall expected early Wednesday. The U.S. National Hurricane Center warns that Otis could be "potentially catastrophic" upon reaching the coast. Its maximum sustained winds have reached 145 mph, classifying it as a major hurricane. As of Tuesday evening, the storm was about 85 miles from the popular beach city of Acapulco, and a hurricane warning was in effect for the coastline from Punta Maldonado to Zihuatanejo. Authorities in the state of Guerrero have suspended school classes and made preparations for opening emergency shelters. The NHC predicts rainfall of up to 15 inches and warns of flash flooding, urban flooding, and mudslides in areas of higher terrain. Additionally, a potentially life-threatening storm surge is expected to produce coastal flooding. While hurricanes are a common occurrence in Mexico, few make landfall as a Category 5 storm.