MEXICO CITY >> Tropical Storm Roslyn gained strength off Mexico’s Pacific coast today and forecasters expected it to be a hurricane when it makes a likely weekend landfall between the resorts of Puerto Vallarta and Mazatlan.

The U.S. National Hurricane Center said Roslyn’s maximum sustained winds had increased to 65 mph today. It was centered about 285 miles south-southeast of Cabo Corrientes — the point of land jutting into the Pacific south of Puerto Vallarta — and moving west-northwest at 7 mph.

Forecasters said Roslyn was expected to continue gaining force and could be a strong Category 2 hurricane before curving northward, brushing past Cabo Corrientes and then reaching the coast Saturday night or Sunday.

Hurricane Orlene made landfall in roughly the same area, about 45 miles southeast of Mazatlan, on October 3.

The hurricane center said tropical-storm-force winds extended out to 90 miles from Roslyn’s core.

Mexico issued a hurricane warning covering the Bahia de Banderas that includes Puerto Vallarta and for a strip of coast to the south of the bay.

The National Water Commission said rains from Roslyn could cause mudslides and flooding. and the U.S. Hurricane Center warned of dangerous storm surge along the coast.

Jalisco state Gov. Enrique Alfaro said by Twitter that any school activities in the region would be canceled on Saturday and he urged people to avoid tourist activities at beaches and in mountainous areas over the weekend.