The seasons are defined by the position of the sun. The sun makes a round a year between the latitude of tropic of capricorn (22.5S) and the latitude of tropic of Cancer (22.5N). Those are the dates of summer solstice and winter solstice. The sun never moves beyond this range, and that's why the long nights/days in the arctic/antarctic circles.

When the sun is away for too long, the earth surface, due to lack of energy source, becomes so cold that it cools the air above (which is a slow process). When the air gets cold, it becomes heavy, relative to warmer air. Once in a while the heavy cold air can't hold it anymore, and pushes out towards the Equator. That becomes a "cold front." Becuase the earth rotates rapidly, it causes the edge of the cold front to "rotate" and hence the strong wind. The direction of the wind is the opposite in the Southern Hemisphere compared to the Northern counterpart (just like the fact that the tolet water spins in opposite direction, as well as the wind in the hurricanes).

If I remember correctly, 10 inches of snow is equivalent to 1 inch of rain. Snow accumulation obviously makes driving more difficult. Places with frequent snow are better equipped to handle snowy road conditions. They often spread sands on snow. I believe the sand is not for friction because obviously it's not much easier to drive on a sandy road. I believe the sand is used because of its low heat capacity plus the large effictive area, in order to melt the snow.