The pilot reported the windsock indicated steady winds out of the south. The closest weather reporting station, 7 miles away, reported winds from 190 degrees at 13 knots. Shortly after he began his landing roll on runway 27, the airplane weathervaned due to a gust of wind. This moved the airplane to the left of the runway centerline. The pilot applied right rudder and the airplane continued down the runway, half way between the centerline and the edge of the runway. The airplane weathervaned again, and the pilot applied power in an attempt to go-around; however, the airplane contacted a snowbank on the left side of the runway and nosed over.