What sky condition is recorded when fog at the surface completely obscures visibility until 650 feet?

The notation VV006 indicates a vertical visibility of 600 feet. This is a specific format used in aviation weather reports to denote that visibility is reduced to a certain height above the ground due to obstructions, such as fog. When fog entirely obscures visibility up to 650 feet, the vertical visibility is reported as the maximum height at which one can see, which in this case translates to 600 feet.

The term "VV" stands for vertical visibility, used when surface visibility cannot be determined due to obstructions. The number that follows indicates the height in hundreds of feet. If the visibility were worse than 600 feet because of fog, this would be accurately represented with VV006, as it describes the situation comprehensively within the conditions described.

Therefore, this notation properly captures the scenario where fog obscures visibility to a height of 600 feet, making it the correct answer for this question.