Recognizing that environmental observations and science are international in scope, the International Group on Earth Observations (GEO) initiated development of a Global Earth Observation System of Systems (GEOSS). The purpose of GEOSS is to achieve comprehensive, coordinated and sustained observations of the Earth system, in order to improve monitoring of the state of the Earth, increase understanding of Earth processes, and enhance prediction of the behavior of the Earth system. GEOSS will meet the need for timely, quality long-term global information as a basis for sound decision making, and will enhance delivery of benefits to society. The 10-year implementation plan of GEOSS identifies nine socio-economic benefit areas. Each socio-economic benefit area identifies several requirements for Earth observation. Precipitation is one of the key observation requirements of GEOSS. It is identified as a requirement, either directly or indirectly, by eight of the nine benefit areas.

The National Oceanic and Atmospheric Administration's (NOAA) Strategic Plan identifies four Mission Goals and a Mission Support Goal, each with several subordinate Programs. NOAA's Line and Staff Offices execute activities required to support these Goals through the NOAA Programs. Each Program has documented the observational requirements it needs to accomplish its NOAA mission in the NOAA Consolidated Observation Requirement List (CORL). Out of 22 Programs that have documented their observational requirements in the CORL, 10 Programs have identified one or more of the following precipitation-related requirements: Precipitation Amount, Precipitation Rate, Precipitation Type, Snow Cover, and Snow Depth. This paper will present a summary of NOAA's precipitation-related observation requirements and the observing systems contributing to the observation of these parameters through an integrated, “GEOSS”, approach.