A major transition in weather and climate prediction is now occurring, one in which real time and retrospective Numerical Weather Prediction (NWP) and global climate (Atmosphere-Ocean General Circulation Models (GCM)) research is spreading from a handful of national centers to dozens of groups, both public and private across the country. This growth of global and regional scale NWP and GCM model development is in part now possible due to (1) the availability of low-cost multiprocessor workstations; (2) the availability of regional scale models that run on these workstations (e.g., MM5); and (3) the availability of climate simulations, analysis and forecast grids from NCEP, GFDL, NCAR and other institutions.

This paper provides a three year status report for the NOAA Operational Model Archive and Distribution System (NOMADS) pilot project. NOMADS addresses the growing demand for real-time and retrospective high volume NWP and GCM model input and output data sets by providing access to distributed data under a sustainable system architecture.