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 program is an example of citizen science.

The CoCoRaHS logo

History

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In 1997, the network was started in Larimer County, Colorado, after a flash flood in Spring Creek killed five people[1] 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.[2]

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:

"The results of the data showed that more than 14 in. (36 cm) of rain fell over southwest Fort Collins, the area where the flood waters originated, while less than 2 in. (5 cm) of rain fell only 3–4 mi (5–6 km) east. The enthusiastic interest shown by volunteers and the great value of the data verified the need for such a service, and CoCoRaHS was born."[3]

Expansion to other U.S. States/territories and other countries

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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.[4]

Order of U.S. States Joining the CoCoRaHS Network[4]
Order of addition to network State/District (in descending order from first included to last included) Time of which CoCoRaHS expanded to specified state/district
1 Colorado 1998
2 Wyoming 2003
3 Kansas 2004
4 New Mexico March 2005
5 Texas April 2005
6 Maryland October 2005
7 Virginia October 2005
8 District of Columbia October 2005
9 Pennsylvania October 2005
10 Indiana December 2005
11 Missouri March 2006
12 Oklahoma June 2006
13 Montana December 2006
14 Illinois December 2006
15 Alaska December 2006
16 Nevada March 2007
17 Wisconsin March 2007
18 Tennessee April 2007
19 South Dakota June 2007
20 Iowa August 2007
21 North Carolina September 2007
22 New York September 2007
23 Florida October 2007
24 Alabama November 2007
25 Kentucky November 2007
26 Oregon Late 2007, Early 2008
27 Louisiana January 2008
28 New Jersey February 2008
29 South Carolina March 2008
30 Rhode Island April 2008
31 Georgia May 2008
32 Washington June 2008
33 Utah July 2008
34 Michigan July 2008
35 Mississippi August 2008
36 California October 2008
37 North Dakota November 2008
38 Idaho January 2009
39 Ohio February 2009
40 Massachusetts March 2009
41 Vermont April 2009
42 Arkansas April 2009
43 West Virginia May 2009
44 Hawaii June 2009
45 Connecticut July 2009
46 New Hampshire July 2009
47 Maine August 2009
48 Arizona September 2009
49 Delaware September 2009
50 Minnesota December 2009
51 Nebraska March 2013
Order of countries and territories joining the CoCoRaHS Network[4]
Order of addition to network Country/Territory (in descending order from first included to last included) Time of which CoCoRaHS expanded to specified country/territory
1 Canada December 2012
2 Puerto Rico June 2013
3 U.S. Virgin Islands February 2015
4 The Bahamas June 2016
5 Guam October 2022

Users

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A 4-inch (10 cm) plastic rain gauge, typical of those used by the CoCoRaHS program. Measurements may be taken and reported either in inches or in millimeters.

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.[5]

Other programs

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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.[citation needed]

Sponsors

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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.[5] 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.[citation needed]

Status

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As of 2015, all fifty states, the District of Columbia, and the Commonwealth of Puerto Rico participate in CoCoRaHS.[6]

Canada

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In December 2011, the CoCoRaHS Canada network began in Manitoba following a massive flood in that province.[7]

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,[7] with over 20,000 participants as of March 2015.[5]

See also

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References

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  1. ^ Browning, Tom (2006-07-30). "Lessons from a killer flood". The Denver Post. Retrieved 2015-03-27.
  2. ^ "Flooding Timeline in Fort Collins". Office of Emergency Management. Archived from the original on 2007-09-27.
  3. ^ "raingaugevolunteers". www.awwa.org. [permanent dead link]
  4. ^ a b c "Order of States Joining the CoCoRaHS Network" (PDF).
  5. ^ a b c "The Community Collaborative Rain, Hail, and Snow Network (CoCoRaHS)". Federal Crowdsourcing and Citizen Science Catalog. CitizenScience.gov. Archived from the original on 2018-07-09. Retrieved 2018-07-08.
  6. ^ "Welcome to CoCoRaHS!". CoCoRaHS. Archived from the original on 2015-03-10.
  7. ^ a b "About CoCoRaHS Canada". CoCoRaHS. Archived from the original on 2014-07-01.

Bibliography

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