Published on 04/30/09

Track Georgia's precipitation

By Sharon Dowdy
University of Georgia

University of Georgia professor Mark Eiteman’s morning ritual begins at 6:45 each day. He brushes his teeth, makes a fresh bowl of fruit, checks his rain gauge and reports the measurement on the Internet.

As an engineering professor with the UGA College of Agricultural and Environmental Sciences, collecting rain data isn’t part of his job. He volunteers to gather the information for the Community Collaborative Rain, Hail and Snow Network, or CoCoRaHS.

“Official measuring stations across the state are sparse, and rainfall can vary quite a bit over short distances,” said Pam Knox, the state’s assistant climatologist and a CAES researcher. “With trained volunteers, CoCoRaHS helps fill these gaps and supply users with a better picture of rainfall patterns.”

The nonprofit national organization will celebrate its first anniversary in Georgia on May 1, she said.

“Volunteering with the network is a great chance for weather enthusiasts and average citizens to be part of a project that collects vital rainfall data,” Knox said. “The data are readily available to the general public and other organizations. It is also critically important to understanding how rainfall varies around the state in times of limited water supply.”

At his Oconee County home, Eiteman records the level in his gauge every day, even when the gauge reads zero.

“As a researcher, I realize that zero measurements are important, too,” he said. “If you leave the recording blank for a day, you aren’t really helping record accurate data.”

Since joining the weather network, Eiteman has made several notable observations. For example, he watched his rain gauge reach the one-inch mark in just 14 minutes one day. He logged into the network that day to see how much rain neighboring counties received. The storm was very isolated.

“This was a prime example of how important zero measures are to data collection,” he said.

Eiteman’s children enjoyed seeing him log the snow that fell on his home in March.

The Georgia network has more than 400 volunteers but still needs more, Knox said, particularly in east-central Georgia near Augusta.

“We need volunteers all over Georgia,” she said. “We are better covered in Athens and in Tifton because of participation from UGA employees there.”

To participate, volunteers must purchase and use a specific rain gauge able to measure to one-hundredth of an inch. It costs $30 including shipping and handling, she said. The volunteers are trained to use an interactive Web site to post data.

The information is used by climatologists, hydrologists, water resource managers, UGA Cooperative Extension agents and experts with the National Weather Service. The CoCoRaHS program started in Colorado in 1998. The network now includes 42 states and more than 12,000 observers. It is funded by the National Oceanic and Atmospheric Administration and the National Science Foundation. To volunteer or to learn more, visit, or e-mail Pam Knox at

Sharon Dowdy is a news editor with the University of Georgia College of Agricultural and Environmental Sciences.