The Next Generation Air Transportation System's (NextGen) Joint Planning and Development Office is a multi-agency and industry partnership working towards the design and implementation of a U.S. air transportation system for the year 2025. A Weather Working Group formed in 2003 to develop and document the weather system required to be in place to support NextGen implementation. During the past year the working group has created a research plan, concept of operations, including a list of operational improvements and required enabling capabilities, and preliminary estimates of cost/schedule/performance for development and deployment of weather systems. The presentation will provide the audience with an update of the activities of the weather working group and describe the work plan for calendar year 2008. In addition, the NextGen weather concept of operations will be discussed at a high level, to include the plans for a multi-agency developed four dimensional weather dissemination system. Additional presentations during this NextGen session will provide information in greater detail.