Rosa weakened to a tropical depression just hours after it formed as a tropical storm off Mexico's Pacific coast, the National Hurricane Center in Miami said.
Rosa had 35 mph winds late Thursday, and was not expected to threaten land, the center said. It was roughly 215 miles southwest of Manzanillo and was moving north at 5 mph.
Mexico’s Pacific coast has been blitzed with hurricanes and storms this year, whereas its Caribbean and Gulf of Mexico coasts have seen little activity.
In October, Hurricane Paul killed two people in northwestern Mexico. In September, Hurricane Lane cost three lives along the Pacific coast and Hurricane John killed at least three people on the Baja California peninsula.