Cold front propagation in the Loisach valley: Simulations with a simple model

Summary

A simple, basically two-dimensional multilevel model is used to simulate the passage of a cold front in the Loisach valley as described by Müller and Sladkovic (1990). It is found that the front moves essentially like a density current on its way from the mouth of the Loisach valley towards Garmisch. However, a quasi-stationary state is attained soon after the front passed the branching point of the valley near Garmisch where the cold air is then flowing east- and westward. This flow state is characterized by downward motion in the Loisach valley proper and rapid ascent above Garmisch. This circulation becomes less intense as the valleys are filled with cold air. The agreement of model results and observations is satisfactory given the limitations of the model.