“Under tornado watch; expecting rough weather all day and into the evening.”
“Plenty of wind and sirens going off most of the evening.”
“Bad situation here with massive tornado moving through town.”
“Bad storms around here, lots of trees down. No power.”
These comments are from a few of the Alabama residents who report daily weather observations to the Community Collaborative Rain, Hail and Snow Network (CoCoRaHS), a citizen science project that gets people all over the country reporting the amount of precipitation that falls where they live.
The reports from these CoCoRaHS weather reporters offer a unique on-the-ground perspective about the devastating thunderstorms and tornadoes that struck the southeast United States on April 27 and the morning of April 28, 2011. More than 160 tornadoes may have occurred in a 24-hour period according to a preliminary report by the NOAA Storm Prediction Center. A coincidence of factors in the atmosphere added up to just the right conditions for twisters that day. (For more information about the science of what happened, check out Bob Henson’s post on Currents, the NCAR and UCAR blog.)
The Community Collaborative Rain, Hail and Snow Network (CoCoRaHS) started in Ft. Collins, Colorado at Colorado State University in 1998 in the wake of a flash flood caused by an intense thunderstorm that stalled over a small part of the city. Weather radar could not 'see' the intensity of the storm. The people who knew how much rain was falling were on the ground in that part of the city. Without warning, the precipitation from the storm flooded the city, costing over 200 million dollars in damage and, unfortunately, five lives. This event emphasized the value of precipitation measurements collected by people and, thus, the need for a program like CoCoRaHS.
Today, CoCoRaHS volunteers can be found nationwide measuring precipitation in backyards of all 50 states as well as the District of Columbia. The project is striving to have as many as 40,000 people participating by the end of 2013.
Sponsored by NSF and NOAA, the CoCoRaHS network aims to collect accurate high-quality precipitation data of all forms - snow, rain, and hail. The National Weather Service, River Forecast Managers, meteorologists and hydrologists use the data on a daily basis. Emergency managers, city utilities and other professionals have practical applications for the data too. Teachers across the country also use the program and data for educational purposes. “Besides all the benefits to the community, it's also fun to participate,” says Noah Newman, CoCoRaHS Education Coordinator.
The CoCoRaHS Network is not just weather data – it’s people. Said Nolan Doesken, CoCoRaHS founder, in a monthly newsletter called The Catch. “Ever since CoCoRaHS has spread across the country, I can't look at weather the way I used to. In years past when we'd see pictures of tornadoes and tornado damage elsewhere in the country, it was always exciting but usually distant and impersonal. Of course we felt for the victims, but they were strangers. Now, with nearly 15,000 of us spread across the country, whenever there is harsh weather anywhere in this country there is usually a CoCoRaHS volunteer experiencing it. “
Sign up as a CoCoRaHS Volunteer Observer and join this grassroots network. You will need a rain gauge, a little training, an interest in reporting the weather where you live, and about five minutes a day.
Lisa Gardiner has a background in several “ologies” – ecology, paleontology and geology. She writes and teaches about nature and environmental science, and also describes the natural world via illustrations and artwork. Lisa is the director of education at the National Ecological Observatory Network (NEON) where she develops educational resources that help connect people with the natural world. Currently, she is exploring the world of citizen science to help inform NEON’s journey into this exciting area. Lisa holds a Ph.D. in Geology and enjoys exploring the Earth from the tops of Colorado’s mountains to the bottom of the sea.