NMME Plans for Sub-seasonal Forecasts

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 been providing real-time seasonal forecasts since August 2011. NOAA will implement the experimental NMME Phase-II seasonal forecast system as part of its operational suite starting August 2015. The NMME 30-year reforecast data and the real-time data are archived and available to the community for research and applications.

The current NMME-Phase II system has been developed and tested as a seasonal forecast system providing forecasts on a monthly basis, although daily data are provided in order to examine higher order statistics. Preliminary research has been done during the NMME Phase-II period to test an NMME protocol as applicable to sub-seasonal probabilistic quantitative predictions. To respond to users' needs in sectors ranging from food and water security and public health, to emergency management and national security for forecast information at sub-seasonal timescales (i.e., lead times from 3-4 weeks), it is a natural next step to explore the potential design, benefits and feasibility of a sub-seasonal NMME prediction system. In this talk we will present a report of NMME Sub-seasonal Forecast System Exploratory Workshop held in March 2015 and discuss the preliminary protocol designed for an NMME sub-seasonal re-forecast and real-time forecast and initial plans for sub-seasonal NMME forecast experiments.