MEXICO CITY (Reuters) - Hurricane Bud, the first Pacific hurricane in the 2012 season, strengthened into a major Category 3 storm on Thursday as it headed toward Mexico's coast, the U.S. National Hurricane Center said.
With maximum sustained winds of 115 mph, Bud is threatening heavy rains and a storm surge around the port city of Manzanillo, the Miami-based center said.
Mexico has no significant oil installations on the Pacific coast, but Bud could hit near the popular tourist town of Puerto Vallarta. The hurricane is expected to weaken before making landfall on Friday.
"Some fluctuations in strength are possible tonight and Friday morning before gradual weakening begins by Friday afternoon. However, Bud is still expected to reach the coast of Mexico as a hurricane," the center said in an advisory.
On Thursday night, Bud was located about 170 miles southwest of Manzanillo, home to Mexico's largest Pacific port, and moving north-northeast at around 10 mph.
Mexico's government issued a hurricane watch along the coast from Punta San Telmo to Cabo Corrientes.
The hurricane is expected to soak the states of Michoacan, Colima and Jalisco and southern Nayarit with around 5 to 8 inches of rain.
In some places, the storm could dump as much as 12 inches of rain, raising the alert for life-threatening flash floods and landslides, the center said. "Preparations to protect life and property should be rushed to completion," it said.
All Mexican ports on the Pacific coast remained open on Thursday afternoon including Manzanillo, where the transport ministry said the weather was calm with cloudy skies.
Most of Mexico's oil platforms and exporting ports are in the Gulf of Mexico and affected by storms in the Atlantic, where forecasters are expecting a "near normal" hurricane season this year with up to 15 tropical storms and four to eight hurricanes.
(Reporting by Mica Rosenberg, Dave Graham and David Alire Garcia; editing by Todd Eastham)