ABSTRACT
At present, NCEP performs ensemble predictions for medium-range forecasts (out to approximately two weeks) with the Medium Range Forecast (MRF) model (Tracton and Kalnay 1993), and out to six months with the NCEP coupled ocean-atmosphere model system (Ji et al. 1994a and 1994b). The latter system includes a Pacific basin ocean model derived originally from the Geophysical Fluid Dynamics Lab oratory modular ocean model, and an atmospheric general circulation model (AGCM) that is a modified version of NCEP’s operational global MRF model (Ji et al. 1994a, Kumar et al. 1996). The AGCM con tains modifications of certain physical parameteris ations designed to improve climate simulations of tropical deep convection and precipitation, as well as the mid-latitude response to tropical SST forcing.
