This report is a description of the Swedish limited area model, at present (June 1982) tested operationally with encouraging results. The models is based on the ECMWF-model, although some simplifications have been done in the physic package. The major differences are that this model uses a simpler radiation scheme although a diurnal cycle is included, and for the convection scheme a simple adjustment is used.

To avoid problems with the poles the grid has been trans formed, and a fictious north-pole is placed at 180° longitude and 30° latitude. A relaxation zone (Kållberg, 1977) is used with a width of 8 points, where the solution of the model and the boundaries are weighted together.