How do you get a foot of #snow from a 996 mb low? Strong air converging then rising rapidly around 10,000 ft (top right). Moist air rising rapidly in a cloud layer with temps -15C to -20C (lower right) produces large fluffy snowflakes (dendrites) that accumulates efficiently. pic.twitter.com/PpIQtt842B

— NWS Boston (@NWSBoston) January 7, 2022