SHERIDAN — In Wyoming, a state dominated by semi-arid and desert climates, precipitation is a big deal. Too much, too fast contributes to flooding while too little can lead to an active fire season and struggles irrigating agricultural land.
Being a headwaters state, where rivers and streams originate, makes Wyoming even more dependent on water that falls from the sky as rain or snow, and knowing how much or how little has fallen becomes key to climate research and preparation for predicted weather patterns.
However, the tricky thing about precipitation is that it can vary greatly within short distances. Measurements taken at Sheridan County Airport may be different from what falls by Sheridan College or in Dayton.
That’s why the Community Collaborative Rain, Hail, and Snow Network is seeking help to gather hundreds, and even thousands, of daily precipitation measurements across the state.
“We’re just trying to fill in more of the holes,” Wyoming CoCoRaHS Coordinator Tony Bergantino said.
Wyoming currently has nearly 350 volunteers who monitor precipitation. Approximately 12 of those rain watchers are in Sheridan County, and Bergantino said the network would like to find more in order to provide better data for the wide variety of individuals and organizations who use it.
The National Weather Service, hydrologists, emergency managers, city utility directors, insurance adjusters, the U.S. Department of Agriculture, engineers, mosquito control staff, ranchers and farmers, outdoor recreationists, teachers, students, community members and more all use CoCoRaHS data on a daily basis, Bergantino said.
For example, ranchers and farmers use the data to monitor and predict water rights because precipitation amounts — or the lack thereof — are a good indicator of what will be in creeks to divert for irrigation come spring.
City officials and emergency management coordinators use CoCoRaHS data to predict run-off levels and flood potential.
State and federal drought monitors rely on the data when determining drought disasters and recommendations on aid for farmers and ranchers suffering from drought.
“It’s good to get zero reports coming in, too. That zero value is just as important,” Bergantino said.
Bergantino stressed that the network is not in competition with the National Weather Service.
“We go hand-in-hand. They use our data and we use theirs,” Bergantino said.
For example, on the CoCoRaHS website, observers can submit information about significant precipitation events — like the rains that fell in Sheridan County last fall — and the weather service uses those reports to issue weather alerts.
Volunteer observers receive a free 4-inch rain gauge, which, in general, should be placed as far away from buildings and other structures as they are high to get the most accurate measurement, Bergantino said. Often 10-15 feet away is enough.
Bergantino said observers can be any age. All that is needed is an enthusiasm for watching and reporting weather conditions and the ability to post water levels to the website every day. At minimum, the water level in the rain gauge should be reported, although those who have the time and interest may also add observational notes.
Snow levels, based on the snow water equivalent, are also important. They can be monitored by bringing the rain gauge indoors and letting any snow inside melt.
The Community Collaborative Rain, Hail, and Snow Network is a nonprofit, community-based network of volunteers who measure and map precipitation in all its forms using low-cost measurement tools and an interactive website. It is the largest provider of daily precipitation observations in the United States and had approximately 19,000 observers nationwide in 2013. Approximately 1.8 percent of those observers were in Wyoming.
• Anyone interested in becoming a precipitation monitor for the Community Collaborative Rain, Hail, and Snow Network should visit cocorahs.org or call Bergantino at (307) 766-3786.