The Experimental MJO Prediction Project

AMERICAN METEOROLOGICAL SOCIETY | 425 W eather prediction is typically concerned with lead times of hours to days, while seasonal-tointerannual climate prediction is concerned with lead times of months to seasons. Recently, there has been growing interest in “subseasonal” forecasts—those that have lead times on the order of weeks (e.g., Schubert et al. 2002; Waliser et al. 2003; Waliser et al. 2005). Th e basis for developing and exploiting subseasonal predictions largely resides with phenomena such as the Pacifi c North American (PNA) pattern, the North Atlantic oscillation (NAO), the Madden–Julian Oscillation (MJO), midlatitude blocking, and the memory associated with soil moisture, as well as modeling techniques that rely on both initial conditions and slowly varying boundary conditions (e.g., tropical Pacifi c SST). An outgrowth of this interest has been the development of an Experimental MJO Prediction Project (EMPP). Th e project provides real-time weather and climate information and predictions for a variety of applications, broadly encompassing the subseasonal weather–cli-