The U.S. National Hurricane Center in Miami said early Friday that Calvin's maximum sustained winds have increased to 50 mph (85 kph).
Calvin is located about 215 miles (345 kilometers) south-southwest of Manzanillo, Mexico, and is moving west-northwest near 15 mph (24 kph). There were no coastal watches or warnings in effect.
Some strengthening is expected during the next day or so with weakening forecast after that.