High Quality Content by WIKIPEDIA articles! Graupel (also called soft hail or snow pellets; METAR code: GS) refers to precipitation that forms when supercooled droplets of water are collected and freeze on a falling snowflake, forming a 2–5 mm ball of rime. The term graupel is the German word for this meteorological phenomenon. Graupel is sometimes referred to as small hail, although the World Meteorological Organization defines small hail as snow pellets encapsulated by ice, a precipitation halfway between graupel and hail.