Our fascination with snow is rooted in centuries-old lore and modern-day fear. Snow has character, ranging from powdery to slushy, sleet-like icy to grainy dots. Understanding the science behind snow might settle our nerves a bit. The physics of snow is a tale of how water and ice temperature interactions within clouds fashion what we eventually see fall to coat our landscapes. Powdery snow forms when critically thick air layers aloft are saturated enough and cold enough for highly efficient snow crystal growth. Sleet-snow mix and plain old sleet occur when an above-freezing air layer aloft resides below the snow layer, but closer to the ground is colder.
