Community Collaborative Rain, Hail and Snow Network

In 1997, the network was started 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 US dollars in damage to the Colorado State University campus.{{cite web |url=http://www.ci.fort-collins.co.us/oem/historical-flooding.php |title=Flooding Timeline in Fort Collins |publisher= Office of Emergency Management The severity of the flood and its widespread spatial variability surprised meteorologists, and Nolan Doesken, a former assistant state climatologist for the state of Colorado, asked for precipitation measurements from private citizens in the area. About 300 responded to his emergency request for data. Said Doesken later: == Expansion to other U.S. States/territories and other countries ==

The program was originally confined to Colorado (the first "Co" in "CoCoRaHS" stood for "Colorado" instead of "Community"), but began expanding to other states, first expanding to Wyoming in 2003, with the last expansion into Nebraska in March 2013. ==Users==

CoCoRaHS is used by a wide variety of organizations and individuals. The National Weather Service (NWS), other meteorologists, hydrologists, emergency managers, city utilities (water supply, water conservation, storm water), transportation departments, insurance adjusters, the USDA, engineers, mosquito control, ranchers and farmers, outdoor and recreation interests, teachers, students, and neighbors in the community are examples of people who use CoCoRaHS data. Other programs In or around 2000, the National Weather Service Lincoln, Illinois independently began a similar program, the Significant Weather Observing Program (SWOP). CoCoRaHS data supplements the more rigorous data from the national program with increased spatial and temporal resolution. Real-time data is also provided by the Citizen Weather Observer Program (CWOP), whose users operate weather stations that automatically report over the Internet, and which supplements the more rigorous data reported by formal surface weather observation stations. The earliest and thus critically important for its long-term historical record from respective locations is the Cooperative Observer program of manually recorded daily summaries. ==Sponsors==

The National Oceanic and Atmospheric Administration (NOAA) and the National Science Foundation (NSF) are major sponsors of CoCoRaHS and the Bureau of Land Management (BLM) is also a partner. Other organizations have contributed either financially or with supplies and equipment. Many other organizations and individuals have also pitched in time and resources to help keep the network up and running. ==Forms==

Gregory Syroney with the Scioto County Storm Chaser Center, in Portsmouth, Ohio created the Significant Weather Report Form PDF File for CoCoRaHS Headquarters in Fort Collins. ==Status==

As of 2015, all fifty states, the District of Columbia, and the Commonwealth of Puerto Rico participate in CoCoRaHS. Canada In December 2011, the CoCoRaHS Canada network began in Manitoba following a massive flood in that province. As of 2014, the network had expanded to the Canadian provinces of Alberta, British Columbia, Manitoba, New Brunswick, Newfoundland and Labrador, Nova Scotia, Ontario, Prince Edward Island, Quebec, and Saskatchewan, with over 20,000 participants as of March 2015. ==See also==