Development and Testing of a New Cloud Analysis Package using Radar, Satellite, and Surface Cloud Observations within GSI for Initializing Rapid Refresh

An initial version of a generalized cloud analysis package which combines the strengths of the RUC and ARPS cloud analysis packages is developed within the GSI framework for the purpose of initializing the Rapid Refresh, which will employ a version of the WRF model as a replacement of the current operational RUC. In addition, the RUC and ARPS cloud analysis packages are implemented within GSI as separate options.

The 13 March 2006 central US squall line case is used to test the cloud analysis packages using the planned Rapid Refresh CONUS settings. Preliminary tests include three experiments that use one of the three cloud analysis packages in their 10-hour long hourly assimilation cycles. Their analysis and forecasts are compared with each other and against another experiment with the same settings but without any cloud analysis. The forecast results are verified against radar and satellite observations.