How did it get there?

So it has been a really long time since anyone posted, and I was faced with a very interesting puzzle today so I figured I would share and see if any of you can figure it out...

Last night it snowed here in Bellingham, probably around 3 inches, lucky for me I get to park in the garage at my house, so I was not forced to brush off my car at 6 this morning. I drove to my carpool lot as usual, parked my car, and got a ride with a coworker. Today was a bit warmer, so a lot of the snow melted, and on the drive home there was basically none left on the roads.

When we got back to the carpool lot I was surprised to see the roof of my car completely covered in 2 FEET of snow. It was basically like a large cake of snow on the top of my car. The hood was completely bare, as were all of the other cars in the lot.

How did it get there?