Wyoming, Colorado need people to report precipitation for life-saving network 

A 2020 severe thunderstorm showing rotation above the house, 4.8 miles north northwest of Ten Sleep, Wyo. Photo by Becky Mills

Residents of rural Wyoming and Colorado can help make a difference during critical surprise flooding crises, by volunteering to report precipitation; which bolsters a weather observer network. Through the network: CoCoRaHS, which stands for Community Collaborative Rain, Hail and Snow Network, volunteers are provided a free rain gauge and issue daily precipitation amounts.  

Currently, there’s a strong need for more people to provide this information in many sparsely populated areas of Wyoming and Colorado. 

“Since there are such open spaces here — areas where we have no data, new observers will help us fill in the blanks, and help more accurately put out the U.S. Drought Monitor maps,” said Tony Bergantino, director of the Wyoming State Climate Office and Water Resources Data System at the University of Wyoming. This program helps farmers and ranchers with any drought impacts, because when people report they’re not receiving rain, the CoCoRaHS network will be able to quantify that certain areas are/or are not getting rain. Relief programs are tied to the Drought Monitor through certain disaster declarations. 

More data points on the CoCoRaHS map are also valuable during intense precipitation events, Bergantino said. 

CoCoRaHS observers report daily but if they’re on vacation, they can submit a multi-day report, where they note the span of time gone and then the amount in the gauge when they return. 

During flooding, observers can file a report any time, and Bergantino will get an email right away; as an immediate heads up that there’s something going on, and, in turn, he alerts the National Weather Service. This information helps NWS meteorologists provide certain details when issuing flood watches or warnings. 

A 2020 flash flood 3 miles south of Ten Sleep, Wyo., on Highway 434 where the road was partially washed out. Photo by Becky Mills


Terril Mills of Ten Sleep, Wyo., was the first CoCoRaHS volunteer to join in Washakie County (code name WY-WH-1.) He has a love of weather and previously tracked precipitation 30 years ago with a funnel and a 1-gallon jug. 

“I became interested when neighbors said, ‘We got 2 inches out of that storm.’ I was skeptical. I would ask if the dog dish had straight sides. They always responded with ‘NO, tapered.’ Then, I explained their measurement was not accurate and probably double what we actually got.” 

When Mills learned that this project that started in Colorado was expanding into Wyoming, he immediately jumped on board and received a free 4-inch rain gauge from Tony Bergantino. 

Wyoming CoCoRaHS observers receive this rain gauge; provided to them by the Wyoming State Climate Office. Photo by Tony Bergantino

“That was not long after the creation of CoCoRaHS. After all these years, neighbors do not talk about their dog dish depth around me, they ask “How much did we get?” Mills said. “I would be happy to do anything to help expand CoCoRaHS. Currently there are no observers around Evanston, nor in the county.” 

His father-in-law in New Mexico also became an observer. 

This photo was taken just after a snow storm near east-central Goshen County, Wyoming. Photo by John Maier

In Torrington, Wyo., CoCoRaHS observer and alfalfa farmer John Maier wants readers to know how easy it is to help and contribute to the CoCoRaHS network. Sending in over 4,600 daily reports since 2010, it is now part of Maier’s morning routine. 

“I think I have a near-perfect record of doing it since 2010. I do it on my cellphone as I get ready to go to work,” said Maier, who’s also an attorney. 

Maier also enjoys being a seasonal evapotranspiration (ET) observer. 

“It’s helpful for me or my neighbors who can see where the water balance is. When it goes down, you can figure out how much water your crops need, so you conserve irrigation water by not over-watering and you don’t stress your crops by under-watering,” Maier said. 


CoCoRaHS is run by the Colorado Climate Center and was founded in 1998 by Colorado’s assistant state climatologist Nolan Doesken, who later became the state climatologist and was adamant about helping save lives; following flooding deaths in Fort Collins, Colo.

Picture from Fort Collins flood in 1997. Photo courtesy Colorado Encyclopedia

“There was a highly localized variance from thunderstorms in western Fort Collins that weren’t well-captured or well-warned at the time, and there were fatalities. Doesken determined the localized area of heavy precipitation led to the flooding, and he thought it would be beneficial to have people in a network and direct access to report this to the NWS,” said Peter Goble, climatologist for the Colorado Climate Center and Colorado CoCoRaHS coordinator.  

Colorado Climatologist Peter Goble at the Fort Collins weather station. Courtesy photo

During that deadly flooding, the headwaters of Spring Creek in southwest Fort Collins flooded into mobile homes, causing several deaths. Those residents didn’t know that at the time, that much heavier rain was falling upstream. 

The CoCoRaHS network was launched a year later in June 1998.  

A 2020 severe thunderstorm showing rotation above the house, 4.8 miles north northwest of Ten Sleep, Wyo. Photo by Becky Mills


Colorado also needs more CoCoRaHS volunteers, especially in rural areas; similar to Wyoming. 

In Colorado, the greatest need for observers is in the eastern Plains; eastern Adams County, eastern Arapahoe County, southern Lincoln County, and further east in Washington County, Logan County and Yuma County, also in eastern and southern Weld County, Goble said. 

This year marks 20 years being a Loveland, Colo., CoCoRaHS weather observer for Chris Knoetgen, who’s also a property administrator at the University Corporation for Atmospheric Research.  

This photo of a rain gauge was taken during a March 14, 2021 snowstorm near Loveland, Colo. Photo by Chris Knoetgen.

“If we have a significant amount of rain to report, it’s forwarded to the National Weather Service who uses our information and compares the precipitation amounts to thunderstorms they see on radar,” Knoetgen said. “So, my report sent with what I just measured could lead to them issuing a flash flood warning and help save lives.” 

A recent Loveland thunderstorm dumped 1.80 inches of rain, but just three miles north, Knoetgen only received a trace of rain; showing how readings can differ.

He has also figured out an easy way to measure snow. 

“If there’s a lot of snow, I’ll melt the snow inside, and pour it back into the gauge to get the accurate liquid reading. Or, you can pour warm water atop the snow to melt it faster, then subtract that extra amount you poured in,” said Knoetgen, who’s also a storm spotter during severe weather, providing life-saving reports to the NWS. 

Snow drifts can make it challenging to measure snow, so observers use their best judgment about how much fell on the ground. Photo by Tony Bergantino

Most of CoCoRaHS observers are heavily concentrated along the I-25 corridor from Fort Collins down to Colorado Springs, also in Pagosa Springs, Durango and Glenwood Springs. However, on the eastern Plains there’s a lack of reports and population is sparse.  

“Part of the issue with the 1997 storm fatalities, which wasn’t well-warned, it wasn’t captured by radar or rain gauges, so by the time the warnings were issued, it was too late to evacuate low lying areas,” Goble said. But for people who can volunteer as a CoCoRaHS observer, lets’ say it’s 9 p.m. and there’s been 2 inches of rain in an hour, I could submit that directly to the NWS, so they can use it to issue, or adjust information for a flash flood warning.”  

Remembering CoCoRaHS founder Doesken who grew up as a farm kid in southern Illinois and had a way of relating to farm audiences, Goble said, “Nolan realized backyard rainfall observations had the potential to save lives.” 

To sign up in Wyoming or for Wyoming CoCoRaHS information: or: 

To sign up in Colorado, contact: or call: (970) 491-8545 or email:

Although the rain gauge in Wyoming is free, the rain gauge in Colorado is not free.  

Colorado CoCoRaHS observers can purchase their own rain gauge at

For information about CoCoRaHS:

Nebraska uses their own NeRAIN program, but began recruiting volunteers for CoCoRHaS after 2012. All their data from standard gauges is uploaded to CoCoRHaS — NeRAIN is a subset of CoCoRHaS.

For persons thinking of volunteering in Nebraska, there are a couple of differences:

  1. Which website would you prefer to navigate? And,
  2. NeRAIN provides the rain gauge for free through various Natural Resource District offices. In Nebraska, CoCoRHaS volunteers buy the same gauge for $40. People looking to join the program should talk to their regional coordinator listed at
More Like This, Tap A Topic