The center's 5-day forecast shows it taking a path that would steer it more toward the mid-Atlantic coast than Florida, perhaps curving into the open ocean without ever threatening land, hurricane center specialist Dan Brown said.
At 5 p.m., the depression was at latitude 13.6 north, longitude 25.6 west, about 190 miles south-southwest of the Cape Verde Islands and a long, long, way - about 3,900 miles - east of Palm Beach, as far away as Anchorage, Alaska.
It was moving west-northwest near 12 mph, having sped up from the 9 mph pace reported in the center's 5 a.m. advisory, and was expected to continue at that speed over the next few days.
Top sustained winds were near 40 mph, just over the 39 mph threshold for a tropical storm, and Bertha was expected to gradually strengthen.
This marks the earliest point on record that a tropical storm has been seen forming this far east, although meteorologists note that records stretch only to the mid-1800s and no one could spot storms off the African coast before the advent of satellites.