Development of a Subseasonal North American Multi-Model Ensemble Prediction System

The North American Multi-Model Ensemble (NMME) research initiative has been testing an experimental forecast system aimed at improved sub-seasonal-to-seasonal (S2S) forecasts based on major coupled global models from US and Canadian centers. The NMME system has provided archived 30-year reforecasts and real-time seasonal forecasts for research, applications, and operational predictions. Based on the success of the seasonal NMME system and the growing demand for subseasonal forecasts, a NMME system focused on subseasonal prediction (e.g. weeks 2-4) is being developed. Similar to the seasonal system, the subseasonal system will provide a multi-model reforecast database for calibration, research, and applications, together with real-time predictions that inform new subseasonal prediction products being developed at the NCEP/Climate Prediction Center. This talk will present preliminary research results that have been performed to test a NMME protocol as applicable to subseasonal probabilistic quantitative prediction as well as plans for development of the subseasonal NMME system.