An optical phenomenon (mainly of the polar regions) that is produced when a uniform cloud cover forms over an unbroken snow cover; with these conditions all sense of depth and orientation is lost in a uniformly white glow.

a condition in which falling, drifting, and blowing snow reduce visibility to almost zero.

A condition caused by falling and/or blowing snow that reduces visibility to nothing or zero miles; typically only a few feet. Whiteouts can occur rapidly often blinding motorists and creating chain-reaction crashes involving multiple vehicles. Whiteouts are most frequent during blizzards.

An atmospheric optical phenomenon of snow-covered regions in which the observer appears to be engulfed in a uniformly white glow. Shadows, the horizon, and clouds are not discernible; depth perception and the sense of orientation are lost; and only very dark, nearby objects can be seen. Whiteout occurs over an unbroken snow cover and beneath a uniformly overcast sky when, with the aid of the snowblink effect, the light from the sky is about equal to that from the snow surface. Blowing snow may be an additional cause. Fr: voile blanc

(Also called milky weather.) An atmospheric optical phenomenon in which the observer appears to be engulfed in a uniformly white glow. Neither shadows, horizon, nor clouds are discernible; sense of depth and orientation is lost; only very dark, nearby objects can be seen. Whiteout occurs over an unbroken snow cover and beneath a uniformly overcast sky, when, with the aid of the snow blink effect, the light from the sky is about equal to that from the snow surface. Blowing snow may be an additional cause. This phenomenon is experienced in the air as well as on the ground.

When visibility is near zero due to blizzard conditions or occurs on sunless days when clouds and surface snow seem to blend, erasing the horizon and creating a completely white vista.

Whiteout is a weather condition in which visibility and contrast are severely reduced by snow and diffuse lighting from overcast clouds.