Bud, which was the first eastern Pacific hurricane of the 2012 season, weakened to a tropical storm, as Mexican authorities in coastal regions braced for heavy rains. Emergency officials have alerted residents before the storm makes landfall and prepared shelters as Bud -- which briefly intensified to a category three storm on the five-level Saffir-Simpson scale -- made its approach. \"We are on alert, we are preparing some 120 shelters in the coastal towns,\" said Colima civil protection chief Melchor Urusua. The storm was about 130 kilometers (80 miles) west-northwest of the port city of Manzanillo at 0000 GMT, according to the Miami-based National Hurricane Center (NHC), and bearing down on the coastline. It was moving northward at 11 kilometers per hour, packing maximum sustained winds of 113 kilometers per hour. The Mexican government discontinued a hurricane warning along the central Pacific coastline from Manzanillo to Cabo Corrientes, downgrading it to a tropical storm warning.  A tropical storm watch was in effect for the coast from north of Cabo Corrientes to San Blas. The eye of the storm was expected to move over land later Friday and Saturday before taking a gradual turn toward the southwest away from the coast on Sunday, according to the NHC. Tropical storm conditions were already affecting part of the coastline. Bud is expected to drop up to 25 centimeters (10 inches) of rain in the Mexican coastal states of Michoacan, Colima, Jalisco and southern Nayarit, with up to 38 centimeters (15 inches) in isolated areas. This rainfall could produce \"life-threatening\" flash floods and mudslides, the NHC said. \"A storm surge is expected to produce coastal flooding near and to the east of where the center of Bud makes landfall near the coast. The surge will be accompanied by large and damaging waves,\" it added. The NHC warned that swells generated by Bud could also produce dangerous surf and rip current conditions. The US National Oceanic and Atmospheric Administration has predicted a \"near-normal\" Atlantic hurricane season is likely. The Atlantic hurricane region includes the northern Atlantic, the Caribbean Sea and the Gulf of Mexico.