As the melting process begins, the air around the snowflake is cooled. At temperatures above 2 C the snowflake will melt to become 'sleet' or rain. In this country, the heaviest falls of snow tend to occur when the air temperature is between zero and 2 C. Individual ice crystals and snowflakes can be the shape of prisms, plates or stars - but all have six sides. 30 cm of fresh fallen snow has about the same water equivalent as about 25 mm of rainfall. There are three different phenomena which affect the British Isles that could loosely be described as hail.
Snow pellets are beautifully white but are easily crushable between the fingers.
They are occasionally called 'soft hail'. Ice pellets are quite moderate in size and are composed of clear ice, sometimes conical in shape. Hailstones are whitish in appearance and vary greatly in size. If a hailstone is cut open, a layered structure like an onion is sometimes apparent. A large hailstone may consist of several layers of clear and opaque ice.