When Christopher Godfrey purchased a rain gauge as a birthday gift for his wife a few years ago, neither of them knew how important that piece of equipment would become to their research.
“I study precipitation and extreme rainfall, so he thought it would just be a fun gift,” Elaine Godfrey says.
Now, the Godfreys check that gauge almost every day, and they record the data for the Community Collaborative Rain, Hail and Snow Network, or CoCoRaHS, a grassroots network of volunteers that records weather patterns in their communities.
“We’re essentially a network of backyard scientists,” says Christopher. “Some of us are actual scientists, but we’re all invested in the work.”
The data CoCoRaHS collects is used by several government agencies, including the National Weather Service, to determine daily rainfall and record local weather events that satellites might not pick up with the same precision.
“Models and satellites are precise in their own right, but these are people who are on the ground,” saysDavid Glenn, North Carolina state coordinator for CoCoRaHS. “It’s the hardcore truth of what happened.”
There are 85 active observers in Buncombe County, but there are still several unobserved territories that the Godfreys would like to see filled. There is a particular need for more rural communities outside the city center to get involved.
“We still have a lot of gaps in the mountains, and precipitation varies based on the location of the gauge,” Elaine Godfrey says. “We don’t have that many gauges, so the more we can get, the better we can understand what kind of microclimates happen around here.”
These microclimates can change from one side of a mountain to the other and are most distinguishable during a storm. Weather patterns vary drastically, especially in the western part of the state, so the more data CoCoRaHS can collect, the better. “There are days when something happens on one side of the mountain that doesn’t happen on the other,” Elaine Godfrey says. “The elevation, wind patterns and general climate all vary so much.”
A social network
The network was founded in 1998 by the Colorado Climate Center staff at Colorado State University and has since expanded to every U.S. state and has a growing presence in Canada. Glenn has been part of CoCoRaHS since 2007 and is also the science and operations officer for the National Weather Service. He started working with CoCoRaHS in South Carolina at Midlands Technical College and continued his work with the network when he moved to New Hampshire, where he became the state coordinator.
Glenn, who volunteers as an observer in Carteret County, also started the CoCoRaHS branches in Maine and New Hampshire and has watched the network expand quite quickly.
“I’ve really been able to see CoCoRaHS grow through the years,” he says. “It’s really incredible to see how many people are involved now.”
Nice and easy
CoCoRaHS observers are responsible for measuring weather patterns in their backyard, and all they need to get started is a rain gauge and some time.
“There’s [extensive] training videos that we have everyone watch,” Glenn says.
The videos teach observers how to read a rain gauge, how to measure snowfall and what to do in case of hail. That’s the only training required to become an observer, and as the county co-director, it’s Christopher Godfrey’s job to answer any other questions about the process.
Glenn says snowfall is one of the most complicated measurements to take, because it requires multiple steps. Observers are asked to bring a sample of the snow inside to measure once it’s melted, which Glenn says is actually one of the most important pieces of data after a major snowstorm.
“When you’re measuring that, you can project how much water is going to run after it snows, which could help predict a major flood,” he says.
Filling in the gaps
Elaine Godfrey previously worked with the National Climate Extremes Committee, where she used CoCoRaHS data during her research on extreme rainfall.
“I was working on extreme rainfall events, so these were the record-setting events,” she says. “These were 10, 15, or 20 inches of rain during one event, and that data helped us accurately record it.”
She says the data helped to clarify the climate variations between major rain gauges, which tend to be in airports and major cities. There aren’t any official gauges set up in those in-between areas. When a historic weather event happens, the observers’ data become especially vital.
“Once something major occurs — I’m talking tornadoes, hurricanes, major storms — our data becomes part of the official record,” says Glenn. “We know exactly what happens at a local level, and that is immediately incorporated into the official data.”
The data have also been used to help city planners, infrastructure engineers and building managers better anticipate the likely effects of weather on the built environment. That was the premise of a 2015 project Christopher Godfrey did in partnership with the N.C. Department of Transportation. By examining historical hourly data spanning a 34-year period (gathered 41 different observation stations), Christopher contributed to a design model that DOT engineers use to “design roads for various climate, usage and traffic conditions,” he says.
By comparing road surface damage against weather data over the expected lifespan of roadways, Christopher helped the DOT refine its expectations for road life in different areas.
Elaine Godfrey has also seen the data used to benefit planners; understanding local weather patterns is vital, she says, for designing any kind of infrastructure or building.
“When you know how much rain falls in a place and what the rainfall records are, you can incorporate those into the plans,” she says. “Especially in certain ravines and microclimates where rain is a major part of ecosystem.”
The pain of no rain
The group also records dry spells, which can be just as extreme as a major storm.
“Our name only says rain, hail and snow, but droughts are just as much a part of our data,” Glenn says. “We have to know how dry climates are affecting local communities.”
Observers are asked to record more aesthetic and nontraditionally measurable data during times of extreme droughts, much like the one that has been affecting Western North Carolina. The Godfreys both say the drought was a difficult time for them as observers.
“It was hard to go out there every day and record zero after zero,” Christopher says. “When we finally got any rain, even one-eighth of an inch, it was a big deal. It made us really appreciate the rain when it finally came.”
Promoting community investment
Several schools also participate in data observations, and Glenn says North Carolina has a large network of student volunteers. In fact, it is second only to Colorado, where the network was started and existed for 10 years before North Carolina’s began.
“Students are able to see a real-world application of what they’re learning,” Glenn says. “These are elementary, middle and high school students who are learning how to interact with data.”
The Godfreys travel around the state raising awareness and getting volunteers, but primarily focus on observing Buncombe County and partnering with surrounding counties. They say the hyperlocal focus is what keeps them invested.
“We are constantly trying to understand the societal implications of meteorological events,” Christopher says. “It’s great because CoCoRaHS is essentially one giant citizen science project.”