The treatment of shallow convection in meteorological models is a subject of controversy nowadays. Different approaches are applied in order to describe the transport properties of the Boundary Layer Clouds. Convection schemes are intended to deal with deep and shallow convection, but have difficulties in representing Stratocumulus properly. Turbulence schemes, when used with conservative variables, manage to reproduce Sc, but have inadequacies in reproducing shallow Cu. The application of the Mass-flux concepts to both convection and PBL schemes seem to be a fruitful approach to a unified description.
During the 5th Workshop of the Boundary Layer Clouds group of the GCSS in August 1998, examples of different approaches will be presented and a comparative study of their performance will be made. Furthermore, a comparison with ATEX observational data set and the LES results will be performed. At this symposium, the main results of this intercomparison study will be presented.