The NCAR CCM as a Numerical Weather Prediction Model

Abstract

The NCAR Community Climate Model (CCM, version 3.6) is evaluated as a numerical weather prediction model. The model was run in real-time mode at relatively high resolution (T126 or approximately 1°) to produce 10-day forecasts over a 1-yr period ending 1 March 2004. The evaluation of the performance of the CCM could be useful for both the climate modeling community as well as the operational forecast centers. For climate modelers, the higher-resolution, short-range forecasts can be used to diagnose deficiencies in the physical parameterizations in the model. While climate models may produce good mean climatologies, they may fail to simulate important higher-frequency phenomena that may be important to climate. For operational centers, the examination of an open, well-developed, and studied model could provide insights that could lead to improvement in their own models. Furthermore, the CCM could be considered a candidate as a member for a suite of models for use in an operational context. And, finally, as operational centers gradually extend their forecast range, and climate scientists are paying more attention to the subseasonal time scales, the study of a climate model in the short range becomes more appropriate.