WORTHINGTON — One resides along the northern shore of Lake Ocheda. The other lives a block south of Lake Okabena — and until Monday, neither had identified the other as a volunteer rainfall reporter for the Community Collaborative Rain, Hail & Snow Network.
What Linden Olson and Milo Hawkinson have come to learn, though, is that rainfall can vary significantly in the nearly three miles that separates their homes.
For instance, during the one-week period of Aug. 23 through Aug. 30, Hawkinson reported 3.16 inches of rain from his home on Dorothea Boulevard. Meanwhile, Olson recorded 3.74 inches from his home on 290th Street. The biggest variation was measured at 7 a.m. last Friday, when Olson recorded 1.25 inches in his standard 4-inch rain gauge and Hawkinson collected just .58 in his rain gauge. The Sunday morning measurement showed 1.77 inches in Hawkinson’s gauge and 1.46 inches in Olson’s gauge.
“It’s interesting to see the big differences in precipitation over short distances,” said Olson, who learned of the network of weather reporters — which goes by the acronym CoCoRaHS — about a year and a half ago while surfing the web.
Meanwhile, Hawkinson became a volunteer rainfall reporter with CoCoRaHS in March 2020 after seeing a Facebook post by the National Weather Service in Sioux Falls, South Dakota, asking for people to sign up and help track the weather.
The requirements for volunteering include using a standard 4-inch rain gauge — Olson acquired his through a Sioux Falls television station, while Hawkinson recently replaced his gauge with one he ordered through CoCoRaHS.
“It’s a volunteer network of people sharing their precipitation (data) over the last 24 hours,” Olson shared. “It doesn’t take much work at all to check the rain gauge every day.”
A bit more is involved, though, when it comes to measuring the snowfall.
“I didn’t realize that you’ve got to catch the snow, thaw it out and measure it,” Hawkinson shared. “That can get a little involved.”
It is rather difficult, agreed Olson.
“In this part of the country, it blows and it’s difficult to accurately measure how much snow really fell,” he said. “I think they understand that too. When you report, you say if it’s accurate or an estimate.”
Olson said he tries to take a core sample from the same place each time. And, as for catching the rain, the gauge needs to be in a place where it isn’t going to catch extra drops from a tree or other object. He put his gauge in the middle of his front lawn.
Volunteers are asked to post their daily rainfall or snowfall measurements at 7 a.m. daily, though there is a range from about 4:30 to 8:30 a.m. that it can be done, noted Hawkinson.
While Olson and Hawkinson track the weather for their own interest and enjoyment, the reports are quite beneficial to the National Weather Service. Hawkinson said if reporters are logging significant rain events, it can lead to an issuance of a flood warning by the National Weather Service.
Meanwhile, Olson sees the reporting as beneficial for farmers.
“If you have farms that are separated by quite a few miles, you might find one site has too much rain to plant one day, and another site didn’t get much of any rain and you can plant the ground or harvest,” he said, adding that there is a lot of free information available on the CoCoRaHS website that would be helpful to farmers.
“I think it also might explain some of the yield differences they find — even in parts of the same field,” he added. “If you have a field that’s fairly large, there could be a difference of a quarter of an inch of rainfall. That could explain the difference in five bushels of grain.
“I think too often we make assumptions that the same amount of rain fell over the same field, and that’s not always true.”
Hawkinson said the same is true in town.
“There’s a lot of difference around town — a half-mile can make a big difference,” he said.
Olson and Hawkinson are among less than a handful of volunteer reporters in Nobles County. Coordinates show there is one reporter from northwest of Bigelow, and another east of Brewster.
“It would be nice if there were more people that would be willing to report,” Olson said. “Over time, maybe we could see if there is a pattern — comparing the Buffalo Ridge to four or five miles on either side.”
Anyone with internet access can visit cocorahs.org to view the weather data recorded there. It is a nationwide database, with reporters also in Canada and the Bahamas.