Abstract Author: Jon Gottschalck, Qin Zhang, Wanqui Wang, Yan Xue, Arun Kumar, Michelle L’Heureux, Mike Halpert
Abstract Title: MJO Event of November 2007- February 2008: Assessment of Global Impacts and Real-time Predictions
Abstract: Strong Madden-Julian Oscillation (MJO) activity was observed during the northern hemisphere winter of 2007-2008 and this event – in overall activity and duration – was the strongest and longest-lived activity since March-to-June 2005. Characteristics of this event are illustrated using typical tropospheric and oceanic observational data and compared with the canonical signature of the MJO. This event had extensive impacts across not only the global tropics but also significantly modified the extratropical circulation at times. The interaction of the MJO activity with the La Nina base state was particularly noteworthy. An extensive evaluation of a number of MJO-related prediction tools will be described in order to diagnose the ability of predicting the initiation and persistence of this MJO event. Products evaluated include forecasts based on data from the Global Ensemble Forecast System (GEFS) and the Climate Forecast System (CFS). Moreover, the impacts of the MJO-related initial conditions on the CFS forecasts of tropical Pacific SST are illustrated and demonstrate the importance of accurately and most effectively including subseasonal variability in seasonal forecast systems.