YourDictionary.com defines whiteout as an optical phenomenon, usually in polar regions, in which the snow-covered ground blends into a uniformly white sky, greatly reducing the visibility of shadows, clouds, the horizon, etc. and one's sense of direction or distance.
Conditions which lead to the whiteout experience are many and occur not only in arctic areas of Canada but also extend to the Canada-U.S. border and areas below the 49th parallel.
Whiteouts often form in conjunction with high winds and snow already on the ground. Visibility is reduced to near zero by blowing snow, school buses are canceled, rural and occasionally city schools are closed and children rejoice as a "snow day" gives them an unscheduled day away from their studies. Blowing snow of this magnitude is termed a blizzard.
Environment Canada, tracking the incidence of blowing snow from 1951 to 1980 found the mean number of days per winter varied from one in British Columbia's southern interior to 20 in Toronto, ON and up to 90 in Canada's arctic near Resolute Bay.
Canadian parents scrambling for last minute child care for school aged children will tell you that blizzard whiteout conditions continue in much the same frequency today.
In whiteouts caused by falling snow, the sheer volume of the precipitation causes visibility to be reduced to near zero. Canadians living in snow belt areas experience extremely heavy lake-effect or mountain effect snow which often result in whiteout conditions. Farmers needing to tend to their livestock in all weather, may string a safety rope from house to barn to avoid being disoriented and lost in a severe snowstorm.
Whiteouts occur in the absence of falling snow when the ground is completely covered in white and diffuse lighting from low lying clouds obliterate surface features. Slopes, surfaces and distance become impossible to discern. An object must be placed on the ground before any defining contrast can be detected. This type of whiteout can be hazardous to skiers who may incorrectly judge the steepness of a slope or the presence of crevasses and find themselves in imminent danger.
Low-level fog covering snow-covered ground may also result in whiteout conditions. Smaller aircraft without automatic pilot capability may not be able to land safely. Major and minor airports have been closed and traffic diverted when these conditions have occurred in Canadian airspace. Bush pilots and ice road truckers must contend with all forms of whiteout in the performance of their daily work.
Follow the links in the Resources below to find video of actual Canadian whiteouts in action.
