The Fifteenth WMO Congress, held in May 2007, endorsed a WMO Strategic Plan for the next four years and beyond that included, with high priority, the need for integration of WMO observing systems and development of the new WMO Information System. The WMO Strategic Plan contains three Top-Level Objectives and five Strategic Thrusts that generate a set of initiatives with corresponding expectations to achieve the Top-Level Objectives. Taken together, the initiatives are structured into eleven Expected Results of which two are (i) the establishment of WMO Integrated Global Observing Systems (WIGOS) and (ii) the WMO Information System (WIS). The full set of WMO observation systems includes the Global Observing System of the World Weather Watch, the Global Atmosphere Watch, several specialized systems such as the Aircraft Meteorological Data Relay, the marine meteorological and oceanographic systems and the developing global networks of hydrological observing systems. All of these systems have many similarities and common cross-cutting elements and there is considerable potential to enhance integration that could result in an increased level of interoperability between the various systems through more standardized architectures and data management. Such integration would amplify the value of observational data for all users, both operational and research while better facilitating multidisciplinary use of observational data. All WMO constituent bodies, several international steering committees and many subsidiary expert-level groups are elements in a complex framework for coordination and collaboration, in which a large number of decision makers and experts from virtually all countries and partner organizations address matters related to observation systems. WMO Congress agreed that better coordinated and more streamlined international management mechanisms should be achievable through enhanced integration and result in important enhanced benefits for Members and their national services and for the Organization as a whole. WIGOS combined with WIS should result in a comprehensive, coordinated and sustainable system of observing systems through ensured interoperability between component systems. The benefits from integration include: reduced financial demands on Members; increased availability of required information; improved access; higher data quality standards; and archiving and technological innovations. Congress envisaged that the integration process would encompass four broad objectives: improved management and governance; increased interoperability between the various systems; address atmospheric, oceanic and terrestrial including hydrological domains as a comprehensive total system; and ensure that broader governance frameworks and relationships with other international initiatives are respected, sustained and strengthened.

The paper discusses progress by WMO Members towards establishment of WIGOS and WIS including the benefits and challenges and outlines a roadmap towards implementation taking advantage of selected pilot projects.