Forecasters issued tropical storm watches for portions of the United States, Cuba and Mexico on Friday after Subtropical Storm Alberto, the first named storm of the season, formed in the northwestern Caribbean Sea.

The center of the storm was located about 110 miles southeast of Cozumel, Mexico, and 180 miles south-southwest of the western tip of Cuba as of the National Hurricane Center's 11 p.m. EDT update.

Alberto was moving east at 5 mph with 40 mph sustained winds. Forecasters expected Alberto to intensify to a tropical storm Saturday morning, but do not anticipate it to become a hurricane.