Tropical Storm Roslyn forms off Mexico's coast, could strengthen into hurricane

Newly formed Tropical Storm Roslyn gained strength off Mexico's southern Pacific coast, 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 50 mph late Thursday night. It was centered about 230 miles south-southeast of Manzanillo and moving northwest at 8 mph.

Forecasters said Roslyn was expected to reach hurricane force Friday night. They said it would gradually shift to a more northerly course and begin moving toward land in the coming days.