When flying over snow-covered ground, when is whiteout most likely to occur?

Whiteout conditions are primarily influenced by the interaction of the pilot's perspective with the landscape and atmospheric conditions. In the case of flying over an unbroken layer of snow in featureless terrain under a uniform overcast sky, the light is diffused, creating a situation where the ground and sky blend together. This lack of contrast makes it exceedingly difficult for a pilot to distinguish between the horizon and the snow, leading to a disorienting visual environment known as whiteout.

In this scenario, the uniformity of both the snow cover and the overcast sky contributes to the loss of visual references. The homogeneous appearance can result in a complete visual whiteout, where there are no cues for altitude or position, increasing the risk for pilots as they may not perceive their altitude or orientation accurately.

Understanding that whiteout is most likely in this specific condition highlights the importance of maintaining situational awareness and the need for additional navigational aids or instruments to assist pilots in these challenging environments.