Ice a density about one quarter of that of pure ice. Hard rime is comparatively dense. Ice pellets are a form of precipitation consisting of small, translucent balls of ice. This form of precipitation is also referred to as "sleet" by the United States National Weather Service. (In British English "sleet" refers to a mixture of rain and snow). Ice pellets are usually smaller than hailstones. They often bounce when they hit the ground, and generally do not freeze into a solid mass unless mixed with freezing rain. The METAR code for ice pellets is "PL". Ice pellets form when a
Cross country running autumn and winter, and can include weather conditions of rain, sleet, snow or hail, and a wide range of temperatures. Cross country running is one of the disciplines under the umbrella sport of athletics, and is a natural terrain version of long-distance track and road running. Although open-air running competitions are pre-historic, the rules and traditions of cross country racing emerged in Britain. The English championship became the first national competition in 1876 and the International Cross Country Championships was held for the first time in 1903. Since 1973 the foremost elite competition has been the IAAF World Cross Country