One type of solid water precipitation -the others being hail
, snow and rime
. Within snow you have your symmetrical snow crystals and asymmetrical snow crystals, more on that later. Anyway, back to graupel.
Sometimes called soft hail or snow grains, graupel consists primarily of a mass of frozen cloud droplets. Sometimes the initial particle consists of a cluster of ice needles or a stellar crystal; when this happens, the particle tends to be conical in form. If the initial particle is primarily an aggregation of cloud droplets, the graupel appears as a lumpy, somewhat spherical particle. These particles are soft, and often when they hit an object they flatten out to appear as a rounded spot of powdery snow with any apparent crystalline structure.
Graupel often forms in strong updrafts of cold air and in blizzard like conditions. They are also formed in lake effect snowstorms. The particles are often highly electrified, and each will produce a static noise upon impact with a radio antenna, either while frozen or recently melted. Also found in severe lightning storms and frequently serves as the core of a hailstone. Usually measures between 1-7mm in diameter