So "D5" hasn't actually taken place yet. Dec 5th wasn't it.  No Avalanche hit on Dec 5th.....but its coming. North American Avalanche Danger Scale  Danger Scale – English In the United States and Canada, the following avalanche danger scale is used. Descriptors vary depending on country. Canadian classification for avalanche size The Canadian classification for avalanche size is based upon the consequences of the avalanche. Half sizes are commonly used.[34] Size 	Destructive Potential 1 	Relatively harmless to people. 2 	Could bury, injure or kill a person. 3 	Could bury and destroy a car, damage a truck, destroy a small building or break a few trees. 4 	Could destroy a railway car, large truck, several buildings or a forest area up to 4 hectares. 5 	Largest snow avalanche known. Could destroy a village or a forest of 40 hectares. United States classification for avalanche size Size 	Destructive Potential[34] 1 	Sluff or snow that slides less than 50m (150') of slope distance. 2 	Small, relative to path. 3 	Medium, relative to path. 4 	Large, relative to path. 5 	Major or maximum, relative to path.