The Regional Climate Model COSMO-CLM (CCLM)

Meteorologisches Institut Universitat Bonn, Germany¨In the early 1990s the German Weather Service (DWD) found that future demands on weather forecasting wouldrequire convection resolving weather simulation. This required grid mesh sizes much less than ten kilometres,which could not be achieved by the Deutschlandmodell (DM), the operational model at that time. DM wasa hydrostatic model and thus limited by physical reasons to grid mesh sizes larger than about ten kilometres.Therefore the DWD decided to develop a new non-hydrostatic model, the Lokalmodell (LM). The LM supersededthe DM as operational weather forecast model in 1999 and after several improvements met the expectations inseveral respects.The same…