What Makes a Successful HPC Community Model? Lessons Learned from WAVEWATCH III

Open-source and open-science approaches are rapidly gaining ground in both research and operations. However, such approaches are not new. Community models have existed for decades. Individual models like WRF for the atmosphere and SWAN for wind waves represent a long history of community modeling. The CESM represents a community approach to coupled climate modeling. Even in operations, much more open approaches to software development are gaining traction at the leading meteorological centers. One example of a community model with a long history is the WAVEWATCH III wind wave model, which in turn grew out of the community WAM model. WAVEWATCH III development started 30 years ago in late 1992. The first public release of WAVEWATCH III almost 25 years ago effectively was freeware. The third release occurred under one of the first (custom) open source licenses. A National Oceanographic Partnership Program effort from 2008-2013 focused on developing full open-science approaches for this model. This paper will review the lessons learned along this journey, and how this helped NOAA to move to a Unified Forecasts System (UFS) open source and open science approach.