A network of weather observers that started with just a couple of volunteers right here in Colorado now has 20,000 members all over North America. It’s called the CoCoRaHS (Community Collaborative Rain, Hail, and Snow) Network.
In 1997, a major flood hit the Fort Collins area. It's referred to as the Spring Creek Flood. Rain gauges in the area measured just one to three inches, but an estimated 13 to 14 inches actually feel near Horsetooth Reservoir.
The assistant state climatologist with Colorado State University at the time, Nolan Doesken, decided to gather some volunteers to measure daily precipitation, in hopes to stay ahead of Colorado's variable weather.
The CoCoRaHS network has now expanded to 20,000 observers all over North America.
Its members measure precipitation. Rain, hail, and snow, manually, every day. They say they can never have too many observers.
The Denver metro area just saw an example on February 22, where we got a very narrow band of snow. A gauge in Arvada measured 5.2 inches for that storm, and the next gauge 5 miles to the south, measured just a half inch in Lakewood. The variability is even more drastic with rain.
“We’ve all seen it. You can look out the window and see it raining across the street, but not on you, and so really that’s the whole point of the program," explained Noah Newman, education coordinator for CoCoRaHS. "Rainfall is so variable. You can have lots of weather stations all over the place, but one storm pops up and slides right in between, and you might never ever know how much rain fell there.”
That is why the Colorado Climate Center, which oversees the network, is still trying to expand their coverage.
Rural stations, in the mountains, foothills, and plains, are needed most, but Newman says they could use your help anywhere, even if you live in a metro area, and your neighbor is already reporting. It could help show the variability of Colorado precipitation.
“Plus if you have a neighbor that’s across the street, well now your data can actually verify each other,” said Newman.
Newman explained that with a manual observation system, data entry errors can happen, so it is good to have another nearby station to compare.
He also says this data has become important to scientists, who recognize the measurements to be credible and use it for things like climate research and hydrology forecasting.
“Your data are being used," said Newman. "We have people that have been reporting to us for years and years, and they’ll send us an email asking, ‘is anyone looking at this data?’ and yes absolutely. People are looking at the data every single day.”
This is not a huge commitment and you would be helping the weather community out a bunch.
It takes about 5 minutes a day in the winter, because you have to measure the snow, and then melt it and measure the water. During the warmer months, it's just a matter of checking the gauge in the morning and reporting the contents.
All you have to do is register at the CoCoRaHS website, watch a tutorial, or attend a class, and buy a manual gauge, which is only about $30. Automated precipitation gauges are not as reliable because they take a lot of maintenance to keep the sensor clear of dirt and debris. So it has to be done manually.
If you go on vacation or just get busy, it’s not a requirement to report every day. Although the more data that gets reported, the more useful that date is.
They also say you don't have to be at a permanent address. Just report at your current address as long as you can, and just change the location of the gauge in the CoCoRaHS database when you move.