AbstractKatabatic flow down long glaciers in high latitudes experiences deflection due to the Coriolis force. If the Coriolis force is added to the classic Prandtl model for katabatic flow, the cross‐slope wind component does not approach a true steady state, but rather diffuses upwards in time. On the other hand, the down‐slope component and the potential temperature perturbations do reach stationarity on the same time‐scale as in the classic Prandtl model. Numerical and approximate analytic solutions are presented describing this spatio‐temporal behaviour. Both solutions are in accordance with physical intuition. The analytic approximate solution can be useful in boundary‐layer parameterizations and data analysis. Copyright © 2007 Royal Meteorological Society