Colorado State’s Coco Rahs Needs Denver-Area Weather Watchers to Help Make Community Drought, Water Use Decisions

Colorado State University’s Community Collaborative Rain and Hail Study, or CoCo RaHS, is recruiting hundreds of weather-watching volunteers to improve precipitation monitoring throughout the seven-county Denver-Metro area before the onset of potentially serious summer drought conditions in the state. CoCo RaHS provides detailed drought and other water decision-making information to municipalities, home owners, industry, agriculture, utility providers, resource managers and educators. CoCo RaHS information is updated daily and available for free public access on the Web at

"CoCo RaHS volunteers learn about weather from top professionals while making a difference by providing valuable information to researchers and water managers throughout the state," said Nolan Doesken, research climatologist at Colorado State’s Colorado Climate Center and director of the CoCo RaHS program. "As Colorado continues to make important decisions regarding water, CoCo RaHS weather watchers are making a big difference in helping track both water supply and demand."

The National Weather Service operates a network of long-term official measurement stations in Colorado. However, these stations are too far apart to provide an accurate picture of statewide storm precipitation totals. Daily results evaluated by CoCo RaHS’s 900 active volunteers show a much more accurate picture of storm and drought patterns.

CoCo RaHS now has been gathering data in the Denver area for two years, but many more weather observers are needed throughout metro-Denver to accurately measure and describe storm patterns. Doesken’s goal is to have at least one CoCo RaHS volunteer per square mile in the metro area, more than tripling the number of weather observers currently in the region. This dense coverage is needed to assess how storms form and move across the area and to pinpoint the localized wet and dry spots in the region.

"Without accurate rainfall data, we may not make the best use of our water supplies and other natural resources," said Doesken. "You might be surprised at how many organizations need and appreciate accurate, local rain and hail reports."

Here are some examples of organizations making use of CoCo RaHS precipitation reports.

– The National Weather Service, one of the largest users of the volunteer program’s data, monitors CoCo RaHS to help track severe weather, issue severe storm warnings and verify forecasts.

– The U.S. Department of Agriculture uses CoCo RaHS information to evaluate drought, hail and crop conditions and to improve estimates of future crop yields.

– The U.S. Bureau of Reclamation and the Northern Colorado Water Conservancy District both use CoCo RaHS data to look at how precipitation affects water inputs into specific river basins and impacts water demands in those areas.

– The Colorado Water Conservation Board and the State Engineer’s Office are interested in CoCo RaHS data for mapping rainfall patterns that can lead to both drought and flood events.

– Denver Water, the Urban Drainage and Flood Control District and other Front Range utility providers monitor CoCo RaHS information to verify rainfall situations that could affect their operations relating to water supply and to storm water runoff.

– Teachers from throughout the state can use CoCoRaHS information to help teach math and science to students. Lesson plans soon will be provided via the Web to teachers who want to use the project in their classrooms.

"This is a community project that benefits the entire state, and anyone can help, regardless of age or education," Doesken said. "The only requirements are an enthusiasm for watching and reporting weather conditions and a desire to learn about rain, hail and snow. And it only takes a minute or two a day."  

Each time a rain or hail storm occurs, volunteers take measurements of precipitation using high quality back-yard gauges. Precipitation reports and observer notes are transmitted via telephone or the Internet to the Climate Center each day. Daily updated maps of rain, snow and hail are automatically generated and used by scientists and resource managers to learn how storms develop and move and to make water-use decisions.

"Despite all of our modern technology, there is still nothing better than a simple backyard rain gauge and someone who is excited to measure it," Doesken said. "Rain is so variable and it affects so much of what we do, that it just makes sense to measure it as accurately as we can."

CoCo RaHS leaders will be recruiting Denver-area volunteers throughout the spring and will be conducting several information and training sessions in the region. Upcoming CoCo RaHS volunteer training sessions in the Denver-metro area, free and open to the public, include:

– Saturday, May 1: 10 a.m.-noon at the Adams County Fair Grounds CSU Extension Building in Brighton;

– Thursday, May 6: 6:30-8:30 p.m. at the Parker Library in Parker;

– Saturday, May 15: 10 a.m.-noon at the Castle Rock Library in Castle Rock;

– Tuesday, May 25: 6-8 p.m. at the Kevler Library in Byers;

– Wednesday, May 26: 6:30-8:30 p.m. at the Castle Rock Library in Castle Rock.

Additional training sessions will be scheduled throughout the Denver-metro area as needed. All training sessions have capacity limits. For more information or to register, visit the Web at, send e-mail to or call the CoCo RaHS office at (970) 491-8545.