Community Collaborative Rain, Hail and Snow Network Community Collaborative Rain, Hail and Snow Network The Community Collaborative Rain, Hail and Snow Network, or CoCoRaHS, is a network of volunteer weather observers in the United States, Canada, and the Bahamas that take daily readings of precipitation and report them to a central data store over the internet. The network was started in 1997, in Larimer County, Colorado after a flash flood in Spring Creek killed five people and damaged structures in the city of Fort Collins, Colorado, including hundreds of millions of dollars in damage to the Colorado State University campus. The severity of the flood and its
Ice pellets a solid mass unless mixed with freezing rain. The METAR code for ice pellets is PL (PE before November 1998). Ice pellets are known as sleet in the United States, the official term used by the U.S. National Weather Service. However, the term sleet refers to a mixture of rain and snow in most Commonwealth countries, including Canada. Because of this, Environment Canada never uses the term "sleet", and uses the terms "ice pellets" or "wet snow" instead. Ice pellets form when a layer of above-freezing air is located between above the ground, with sub-freezing air both above and below