CoCoRaHS (The Community Collaborative Rain, Hail and Snow Network) is a citizen science program where thousands of volunteers across the entire country measure and report the amount of precipitation that falls each day in their own neighborhood (see http:www.cocorahs.org). In the next three years CoCoRaHS will use strategies from the "Citizen Science Toolkit" and align activities to the "Essential Principles to Climate Science" to engage thousands more participants in collecting, reporting and exploring precipitation. Evapotranspiration measurements will be added to better teach and demonstrate the hydrologic cycle in action. Through strong NOAA partnerships with the National Weather Service, the National Climatic Data Center, the Earth Systems Research Lab and the National Operational Hydrologic Remote Sensing Center, precipitation data quality and accessibility for professional users will be enhanced. The CoCoRaHS network will be constructing training, data entry and visualization tools utilizing Web 2.0 concepts, cyberlearning tools and hand-held device applications with a goal of increasing participation and expanding the current volunteer network into broader, younger, more diverse and more interactive audiences.