Mexican authorities put its Pacific coastline on alert Friday as Hurricane Bud was set to make landfall later in the day after being downgraded to a category one storm, officials said.

Bud, the first eastern Pacific hurricane of the 2012 season that briefly grew to a category three storm this week on the five-level Saffir-Simpson scale, prompted emergency officials to alert residents along the western coast and prepare shelters.

The hurricane was about 130 kilometers (80 miles) west of the port city of Manzanillo at 2100 GMT, according to US storm monitors, and bearing down on the coastline. It was moving northward at 11 kilometers (seven miles) per hour.

Packing sustained winds of 120 kilometers (75 miles) per hour, Bud prompted hurricane and tropical storm warnings and watches along the central Pacific coastline, the Miami-based US National Hurricane Center said.

"Hurricane conditions could reach the coast within the hurricane warning area this afternoon, with tropical conditions expected to continue today, making outside preparations difficult or dangerous," it said.

"Preparations to protect life and property should have already been completed."

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 in some areas.

This rainfall could produce "life-threatening" flash floods and mudslides, as well as a storm surge with coastal flooding near and to the east of where the epicenter makes landfall, the NHC said. Swells generated by Bud could also produce dangerous surf and rip current conditions.

Mexican authorities were battening down the hatches, as hurricane warnings went up from Manzanillo in the west to Cabo Corrientes further north.

"We are on alert, we are preparing some 120 shelters in the coastal towns," said Colima civil protection chief Melchor Urusua.

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.