why does snow seem to blow the opposite direction when near buildings?



While at work today, I was looking outside and noticed the snow was blowing in one direction, but near the windows and building, it was going in the opposite direction, sort of diagonal to where it was blowing elsewhere. Is this caused by the way air is flowing around the building? Or some sort of heat soak effect from the building itself causing the air close to it to cause a change in direction of the snow?

In: Physics

Air cannot go through buildings. Thus it must change direction to avoid the building. Snow tends to move at roughly the same speed as the air around it, so the snow must also mostly go around the buildings.

Think about a river. The water doesn’t always flow in one continues way. It is turbulent, with eddies and back flows and all sorts of thing. Behind a rock in the river you’ll notice that water is flowing upstream in the turbulence. Wind does the same thing.