You might not need a weatherman to know which way the wind blows, but consider: The weatherman may need you.
A nationwide network of citizen weather observers that started in Fort Collins 20 years ago, while still thriving, is seeing a shortage of participation lately in Boulder. More active members are needed locally to boost its effectiveness.
CoCoRaHS may sound like an exotic snack food, but it is credited as being critical in providing meteorologists a clear picture of the way the thousand-year rains of 2013 unfolded along Colorado's Front Range. A well-populated and engaged network will be just as important to a good understanding of the next weather event that wreaks havoc on the lives of people in Boulder County and beyond, its supporters say.
"The reason why CoCoRaHS is so important is, in order to forecast weather better, we need to better understand what did happen," said Boulder meteorologist Matt Kelsch, the program's coordinator for Boulder and Broomfield counties. "We increasingly have these really high resolution models that are showing us detail down to parts of counties, and stuff like that; very, very fine detail. But they're not always correct.
"And the way we can learn to make models better is to know what happened. If we just relied on airports, which are historically where weather was recorded, there wouldn't be anything in Boulder County, except for one point."
CoCoRaHS stands for Community Collaborative Rain, Hail & Snow Network, and it might be more challenging to say it than it is to participate, according to its boosters.
Downtown Lyons resident Bunny Pfau has been a steady contributor since 1999, sending in measurements on a daily basis from the 11-inch rain gauge posted strategically on a fence in the corner of her front yard. Like all gauges employed in the network, hers measures precipitation to the hundredth of an inch.
"I'm not a scientist," said Pfau, who works in IT at the National Oceanic and Atmospheric Administration. "I don't have a degree in any physical science. But I moved out here from the Midwest a long time ago, and I was always kind of amazed by how the weather was so different, from one area to another."
Before she ever heard about the observers' network, she often set out a rain gauge or even just an empty vase, out of a gardener's curiosity about what was really coming from the skies, and how much.
"When I heard about CoCoRaHS, that they were looking for regular, backyard weather observers, I thought, that's exactly what I am already doing, just paying attention to the environment," she said.
The only prerequisite to participating, according to Pfau, is, "You just have to be interested in the world around you."
'Something already there'
The birth of the network has its roots in the aftermath of the Spring Creek Flood that ravaged Fort Collins in July 1997, after 14.5 inches of rain fell there over two days.
Colorado State Climatologist Nolan Doeskin, who is based at Colorado State University, was charged with piecing together what had happened, climatologically.
"And in the case of the university, there was a lot at stake depending on the source of the water and the cause of the flood and the insurance either was or was not going to cover," he said.
"We put out an all-points bulletin for any rain amounts that were measured, and in a week, we had our first guess of what the rain pattern had been. And in another couple months, we were able to refine that, almost by going door-to-door, looking for any sort of receptacle or any sort of actual rain gauge anyone might have had," Doeskin recalled.
"In total, we got about 300 data points of some varied amount of worthiness, and from that we were able to say that in the city limits of Fort Collins, 14.5 inches of rain had fallen in the city. That was the beginning of CoCoRaHS, because as we were going door-to-door, people were saying, 'If you had told me you were interested, I would have had a gauge out for you.'"
The network's first two counties were Larimer and Weld, soon followed by Boulder County and spreading up and down the Front Range. Originally called the Colorado Collaborative Rain, Hail & Snow Network, "Community" replaced "Colorado" in the title as it spread to eventually include all 50 states, plus several U.S. territories and Canada.
Chad Gimmestad, a meteorologist at the National Weather Service in Boulder, is a participant in the network and also serves as a liaison for the enterprise to the NWS.
Rainfall from September 2013 storm
Readings, in inches, are for 24-hour periods ending at 7 a.m. For example, rain that fell the afternoon of Sept. 9 appears in the Sept. 10 total
Boulder readings
Sept. 9: 0.00
Sept. 10: 1.01
Sept. 11: 1.10
Sept. 12: 7:30
Sept. 13: 5.21
Sept. 14: 0.09
Sept. 15: 0.41
Sept. 16: 2.01
Sept. 17: 0.01
Total: 17:14 inches
Lyons CoCoRaHS readings, courtesy of network observer Bunny Pfau
Sept. 9: 0.00
Sept. 10: 1.11
Sept. 11: 0.52
Sept. 12: 3.64
Sept. 13: 2.38
Sept. 14: 0.04
Sept. 15: 0.04
Sept. 16: 1.69
Total: 9.42 inches
For information on joining CoCoRaHS, go to cocorahs.org
"They tapped into something already there," Gimmestad said. "A lot of times we're recruiting, and someone will hand us a book with 15 years of data that they have recorded, and say, 'Do you want that?'
"A lot of people are already doing this. A lot of people are fascinated with the world around them, and are making observations, and taking notes. It's not hard to convince people to do it."
The observing program was an essential tool for meteorologists to fully assess the memorable Front Range snowstorm of March 2003, and more recently, the September 2013 storms, which drenched Boulder with a record-shattering 17.14 inches of rain in one week.
"It was extremely important," Kelsch said. "The rain that fell, we never would have been able to analyze it with quite the detail we did, unless we knew what happened. And CoCoRaHS volunteer observers filled in so many of the gaps."
At the other end of the spectrum, even when there's nothing to report, the network wants those numbers, too.
"We do encourage people to report zeros," Kelsch said. "During drought and during fire season, that's really important, to know where it didn't rain. People often don't, and that's okay. It's volunteer. But we tell them we like the zeros. They're important."
'Totally addicted'
For a variety of reasons — some longtime participants have died, others have move away — the number of people contributing to the network has tailed off.
In this month's late-season snow that Doeskin called "the big slop," he said, Boulder was "down to only about 10 (citizen reports) from this recent storm. In terms of within the Boulder city limits and within a few miles of the Boulder city limits, the reporting has really dropped off."
Kelsch is concerned, too.
"For regular participants in Boulder ... about 15 reported last week" during the late-season snow, Kelsch said. "The county is roughly about 100. There are over 300 people registered, but some have left, and some only report occasionally. On a good day, we probably get between 50 and 100."
Kelsch said he would like to see the city back up to about 20 to 25 participants, and also to fill in many "blank areas" for reporting in the mountain communities.
Pfau is so enthusiastic about the program, she even suggested she'd assist anyone who balks at the $30 it costs to buy the recommended 4-inch diameter rain gauge, which is easily mastered by new users.
"It sounds a little intimidating to think about, giving daily measurements, but you don't have to get them daily," said Pfau, who nevertheless does do so herself. "You can just report when you find it interesting."
People on her block, Pfau said, used to think she was "kind of silly" for being so intent with her data collection and reporting, which is done easily online or by a telephone app.
"But the gardeners would say, 'That's really cool' — and now they ask me what the rainfall totals are." With an exasperated laugh, she added, "There's always someone trying to dispute what I get."
Pfau doesn't sound as if she's at any risk for quitting the network.
"I can't," she said. "I'm totally addicted. I think, I have these 17 years of data. It must be valuable to someone, in terms of climate. Another day or week passes, and I keep recording it. I'm always curious what fell."
Charlie Brennan: 303-473-1327, brennanc@dailycamera.com or twitter.com/chasbrennan
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