Improvements of a Mixed-Phase Cloud Scheme Using Aircraft Observations

To improve the quality of forecasts of mixed-phase clouds in winter storms, some aspects of a cloud scheme are examined in detail. Modifications to the basic formalism and specification of selected parameters of the cloud model are studied, and simulation results are compared with aircraft observations and satellite data. In particular, a sensitivity study to the parameterization of the ice particle size distribution is presented. A special technique allowing the reconstruction of any model variable along a virtual aircraft trajectory is used to compare model results with aircraft observations. It has been possible from these comparisons to optimize the scheme and improve the quality of forecasts.