What makes a successful community model for research and operations? Lessons learned from WAVEWATCH III®

Abstract Physics-based numerical models form the foundation of both scientific research and operational prediction of our environment, including the atmosphere, sea ice, oceans and more. With the increasing availability of compute resources for researchers and the general public, many such modeling efforts have been or are moving to an open-source and open-science development approach. Some examples of such models and modeling system in the US are the National Center for Atmospheric Research’s (NCAR) Weather Research and Forecasting (WRF) and Community Earth System Model (CESM). Similarly, The National Oceanic and Atmospheric Administration (NOAA) is moving to a community Unified Forecast System (UFS) approach for both research and operations. One of the early open-source and open-science environmental models is the WAVEWATCH III ® (WW3) wind-wave model as originally developed at NOAA. This essay provides a history of this model while extracting lessons learned for community modeling. It presents sixteen such lessons, ranging from coding principles to code management to community building and governance. It is expected that most lessons learned are generally applicable to community modeling, with the caveat that the WW3 community is relatively small, and that some lessons, as discussed, might not “scale up” to much larger modeling systems and communities.