The Community Collaborative Rain, Hail, and Snow Network: Informal Education for Scientists and Citizens

Community Collaborative Rain, Hail, and Snow Network (CoCoRaHS) originated in the aftermath of a flash-flood storm that dropped more than 12-in. of rain over a small portion of Fort Collins, Colorado, on 28 July 1997, and a similar storm the following evening over the grasslands of northeastern Colorado. These floods were responsible for several fatalities and at least 200 million in property damage. Neither event would have been accurately recorded by existing networks of official weather stations. National Weather Service (NWS) radar also failed to assess the severity of these storms (Kelsch 1998a, b; However, when the citizens of these areas were asked to help, they enthusiastically provided scientists with a wealth of information from their own backyard observations. These data eventually resulted in the very accurate mapping of precipitation from the Fort Collins flash flood that continues to be used by engineers, hydrologists, weather forecasters, city planners, emergency managers, attorneys, teachers, historians, and many others for such applications as flood forecasting, drought monitoring, verification of radar-estimated precipitation, and climate trends.