Did you know that the temperature from the top of the snowpack to the ground typically goes from air temperature to zero (C)?
And that persistent cold air temperature results in snow faceting, which rots the snow near gradient closer to "warm"? The "fresh" snow above that is ready to go and make your life hell.
There are a number of factors that can create the phenomenon you experienced. Sun or wind or both. If you are on skis when this is happening, life sucks.
In Canada we have AST courses that go into all of this combined with behavioral psychology as we have a tendency to seek out the worst places to play.
