Vortex: Any circular or rotary flow in the atmosphere that possesses vorticity when a small air parcel spins as it moves along its path.

Friday: Chance of snow, 70 percent

Hi: 22

Low: 11

Saturday: Chance of snow, 30 percent

Hi: 24

Low: 6

Sunday: Chance of snow, 30 percent

Hi: 22

Low: 4