One of the major goals of past and present research programs has been the improvement of our current understanding and prediction of extended range weather forecasts as well as climate variations from seasonal-to-interannual time scales. The Madden-Julian Oscillation (MJO) is the most important mode of tropical intraseasonal variability with potentially important influences on extra-tropical medium-to-extended range weather forecasting, Asian-Australian monsoon activity, and even variability in the equatorial Pacific thermocline structure via its close association with westerly wind bursts.
This paper presents results from our current research to assess the predictability of the MJO. Outgoing Longwave Radiation (OLR) and National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis for the period January 1985-February 1990 are used to identify and classify events according to the phase of the MJO. Fifty-day forecasts from the NCEP Medium Range Forecast (MRF) model during the Dynamical Extended Range Forecast (DERF) experiment of January 1985-December 1989 are used to investigate the predictive skill of the MJO. The presentation will address overall systematic errors in the NCEP/MRF model on intraseasonal time scales and forecast errors associated with different manifestations of the MJO.