National Weather Service

Washington joins CoCoRaHS (pronounced Koh Koh Rawz)!
On June 1, 2008, Washington joined the Community Collaborative Rain, Hail and Snow Network (CoCoRaHS). CoCoRaHS is a growing, community-based network of volunteers of all ages and backgrounds, who take daily measurements of rain, hail and snow in their backyards. This supplemental network, which began in the late 1990s in Colorado, allows volunteer precipitation observers to collect and enter rainfall, snowfall, hail and snow reports via a web-based system. The data supplement current observation networks (e.g. NWS Cooperative Observers) and are displayed on maps that can be accessed by anyone 24/7 with Internet capabilities. CoCoRaHS is also a great educational tool. Students and teachers can monitor and learn about their local climate and also see their information updated immediately on the Internet.

Why Do We Need Volunteer Precipitation Observers?
Each time a rain, hail or snow storm crosses your area, volunteers are needed take measurements of precipitation from as many locations as possible since precipitation can vary significantly across short distances within our region. These precipitation reports are recorded on the CoCoRaHS web site www.cocorahs.org The data are then displayed and organized for many of our end users, including the National Weather Service, to analyze and apply to daily situations ranging from water resource analysis and severe storm warnings to neighbors comparing how much rain fell in their backyards.

Training Sessions
NWS Spokane will conduct a series of remote, CoCoRaHS teletraining sessions this summer and early fall. To register, please click on a link below. Robin Fox and Ellie Kelch will conduct the training sessions remotely using GoToMeeting software from the NWS office in Spokane. All you need is an Internet connection, preferably high-speed, and a separate telephone line. Space is limited and registration is requred in order to send you login and telecon info via email.

How Do I Join?
We encourage anyone who has an interest in the weather, a desire to learn more about weather and climate, and enthusiasm to report daily rain, hail and snow observations to join CoCoRaHS.

First, visit the CoCoRaHS webpage and learn about the program. If you would like to become an observer, you can sign up online.

If you're interested in being a Volunteer Coordinator for your local area, or county, then contact your regional or state CoCoRaHS coordinators and let them know! A list of coordinators can be found here.

What Do I Need?
Each observer will need:

Enthusiasm and desire to watch the weather.
Willingness and dedication to take regular daily precipitation measurements, preferably between 6-9 AM.
Participate in a group or online training session.
A manual 4-inch rain gauge, available through a preferred online CoCoRaHS vendor.
Computer with internet access.

Interested in Becoming a CoCoRaHS Observer?
Visit www.cocorahs.org and download an application. An on-line version is also available.

Picture of an official CoCoRaHS rain gauge.