The Goddard Cumulus Ensemble (GCE) model, a cloud resolving model (CRM), has been developed and improved at NASA Goddard Space Flight Center over the past two decades. The development and main features of the GCE model were published in Tao and Simpson (1993) and Tao et al. (2003b). A review of the applications of the GCE model to develop a better understanding of precipitation processes can be found in Simpson and Tao (1993) and Tao (2003). The 3D version of the GCE model is typically run using 256 x 256 up to 1024 x 1024 horizontal grid points at 1-2 km resolution or better. An MPI version of the GCE model was recently developed (Juang et al. 2006). It is well documented and easy to modify and improve. It is also flexible enough to run on many different platforms using any number of CPUs.