Updated at 12:42 a.m. ET: Alberto, the first named storm of the 2012 Atlantic hurricane season, weakened to a tropical depression Monday night as it continued moving eastward Monday night off the coast of Florida.
As of 11 p.m. ET, Alberto was located about 245 miles southeast of Charleston, S.C. It was moving at 13 mph and had maximum sustained winds of 35 mph, the National Hurricane Center in Miami reported.
There were no watches or warnings anywhere along the East Coast of the United States.
Alberto is the earliest-forming tropical storm in the Atlantic since Ana in 2003.
It also makes this the first year in which a tropical storm has formed before the start of the hurricane season in either the Atlantic or Pacific basins.
Meanwhile in the Pacific, a tropical depression that has formed south of Mexico was expected to strengthen. The depression's maximum sustained winds were near 35 mph, but it was expected to reach tropical storm strength -- maximum sustained winds between 39 mph and 74 mph -- later in the day. It was centered about 535 miles south of Acapulco, Mexico.
The Associated Press contributed to this story.
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