MesoWest began over ten years ago as a result of the need to integrate the collection, archival, and distribution of weather observations available from hundreds of sources available around the nation. MesoWest is now used extensively for operational, research, and educational use with specific applications developed for fire weather operations (Realtime Observation Monitoring and Analysis Network- ROMAN). Coordination with the staff of the Earth System Research Laboratory, who maintain the Meteorological Assimilation Data Ingest System (MADIS), is essential to manage metadata, acquire new data sources, and deliver data to government and public users.

Equipment and maintenance standards, siting, misreporting of station metadata, and the representativeness of the observations to characterize the surrounding conditions are particularly critical for mesonet observations. Nonetheless, mesonet observations provide an essential supplement to the existing large government networks. Obtaining accurate metadata remains a particular challenge for the integration of observations from a variety of networks. Results from data withholding experiments (randomized and network-specific exclusion of observations from surface analyses) will be used as a means to discuss the potential impact of expansion of existing networks as well as installation of new ones.