Lake effect snow is a phenomenon that occurs as cold air moves over a relatively warm lake. Warm, moist air rises and condenses to form narrow bands of clouds that can produce heavy snow downwind of the lake, producing snowfall rates of 2-3" per hour. #WeatherKnowledgeWednesday pic.twitter.com/6Itl5LAD2P

— NWS Boston (@NWSBoston) January 6, 2021