Range 6.1 million km is the first that tests the accuracy of the weather forecast.

Range : 6.1 million km ( 3.8 million miles) This image of clouds in Neptune's atmosphere is the first that tests the accuracy of the weather forecast that was made eight days earlier to select targets for the Voyager narrow-angle camer. Three of the four targeted features are visible in this photograph; all three are close to their predicted locations. The Great Dark Spot with its bright white companion is slightly to the left of center. The small brig&ht Scooter is below and to the left, and the second dark spot with its bright core is below the Scooter. Strong eastward winds -- up to 400 mph -- cause the second dark spot to overtake and pass the larger one every five days.