Blizzard
When winds of 40 km/hr or greater are expected to cause widespread reductions in visibility to 400 metres or less, due to blowing snow, or blowing snow in combination with falling snow, for at least 4 hours.
http://www.ec.gc.ca/meteo-weather/default.asp?lang=En&n=D9553AB5-1#blizzard
Severe Winter weather
Alberta Clipper
The Alberta Clipper is a fast moving low pressure system that begins in Alberta. The storm usually brings high wind and a sudden drop in temperatures with little snow.
The Alberta Clipper can cause a drop in temperature of 16 degrees Celsius in 10 to 12 hours. Biting winds from 56 to 72 km/h can cause windchill values of -30 to -40 degrees Celsius.
Extreme Cold
When the temperature or wind chill is expected to reach minus 40°C for at least two hours.
Frostbite is an injury caused by freezing of the skin and underlying tissues. First your skin becomes very cold and red, then numb, hard and pale. Frostbite is most common on the fingers, toes, nose, ears, cheeks and chin. Exposed skin in cold, windy weather is most vulnerable to frostbite. But frostbite can occur on skin covered by gloves or other clothing.
Avalanche
An avalanche is a moving mass of snow that may contain ice, soil, rocks, and uprooted trees. The height of a mountain, the steepness of its slope, and the type of snow lying on it all help determine the likelihood of an avalanche. Avalanches begin when an unstable mass of snow breaks away from a mountainside and moves downhill. The growing river of snow picks up speed as it rushes down the mountain. Avalanches have been known to reach speeds of 245 miles an hour (394 kilometers per hour)—about four times as fast as the speediest downhill skier.
Winter Weather
Winter Weather Events
1. Rogers Pass Avalanche , March 5, 1910
62 Train men and labourers died when their engine was hit by an avalanche and hurtled 500 meters into Bear Creek.
2. World's worst Iceburg Incident, April 15, 1912. The "unsinkable" Titanic hit an iceburg 700 kms southeast of Newfoundland causing the death of 1,500.
3. Storm claims sealers, April 1, 1914, 77 sealers froze to death in a violent storm on ice off the Southeast coast of Labrador.
4. Victoria's Snowstorms of the Century, December 28 - 29, 1996. The snowstorm dropped 80 cm of snow in 24 hours. The clean up cost exceeded 200 million dollars.
5. Record Windchill, January 28, 1989. The temperature dropped to - 51 in Pelly Bay, NWT but with windchill equivalent reached - 91 C.
6. Ice storm of the century, January 4-9, 1998, hit Eastern Canada, causing hardship for 4 million people and costing 3 billion. Losses included millions of trees, 130 transmission towers, 120,000 km of power and telephone lines. Power outages lasted from several hours to several weeks.