Graupel is a type of precipitation that is distinct from snow, sleet, and hail. It is also known as "snow pellets" or "soft hail" because the graupel particles are fragile and generally disintegrate when handled. Graupel forms when supercooled water droplets freeze onto a snow crystal, a process called riming. The resulting pellets are small, soft, and opaque, with a diameter of 2-5 mm. Graupel is most commonly found in winter storms and at higher elevations, but it can also occur in thunderstorms with cumulonimbus clouds. The METAR code for graupel is GS.

In summary, graupel is a type of precipitation that forms when supercooled water droplets freeze onto a snow crystal, resulting in small, soft, opaque pellets that are distinct from snow, sleet, and hail.