The North American Multi-Model Ensemble Operational Phase 2019-2020 Annual Report  

Summary

The North American Multi-Model Ensemble (NMME) continued to deliver benefits to the subseasonal-to-seasonal operational forecast entity within NOAA, the Climate Prediction Center (CPC), and to the larger research community. Overall data usage from the operational data delivery point remained stable, with about 3000 active users each month. Data was delivered on time for all months, though in one month there was a quality issue corresponding to a major component upgrade. The system continues to produce skillful information that can be easily translated into official outlooks, with the modeling suite showing skill over the North America domain in almost every issuance since 2012, for both temperature and precipitation. Regionalized verifications, as well as those focused on specific seasons, have provided insight into what modes contribute to low-skill outlooks, feeding back from operations to research. The number of products being derived from the NMME models is increasing, with several new applications under development by NOAA and other entities, showing how the research can feed into operational entities. The NMME model suite continues to evolve, as older models are retired and replaced with new models; model replacements from three modeling centers are planned for 2021. Understanding the dependencies and implementing some initial internal controls to document and track downstream dependencies, as well as informing users of the sustainable reliability, will be critical in the coming years.