At 11 a.m. EDT (1500 GMT), Melissa was centered about 570 miles (917 kilometers) west of the Cape Verde Islands and posed no immediate threat to land, according to the National Hurricane Center. The system was moving west-northwest near 13 mph (21 kph) and its maximum sustained wind had slowed to 30 mph (48 kph) - down from 45 mph (72 kph) on Saturday.
Karen faded into an area of disturbed weather Sunday and the hurricane center quit issuing advisories for the system. Early Sunday, it was centered about 495 miles (797 kilometers) east of the Leeward Islands.
In the eastern Pacific, Tropical Storm Juliette was about 335 miles (539 kilometers) off the coast of Mexico but did not threaten land.
Meanwhile, Mexican officials reported Sunday that the death toll from Hurricane Lorenzo, which faded after hitting Mexico's Gulf coast on Friday, had risen to six with the discovery of the body of a 19-year-old man who had been washed away by a flooded river while fishing.
Forecasters expect this year's Atlantic hurricane season to be busier than average. Last month, they said as many as 16 tropical storms were likely to form, with nine strengthening into hurricanes. The season runs from June 1 to Nov. 30.