Objective Forecasting of Foehn for the Subgrid Scate W]pp Valley

This study provides a metlod for an objective, probabilistic forecast offoehn based on the operational global model of the European Centre for Medium-Range Weather Forecast (ECMWF). Foehn strongly depends on topographical features, which are not yet resolved in operational global models. Therefore the proxi-parameters vertical of potential temperature 10, cross-barrier pressure dffirence lp, and downstream wind v, derived from the well lnvestigated foehn dynamics are studied for their suitabili6r as foehn predictors. Testing them for the subgrid scale Wipp Valley, lA and lp yielded better results than y. Further improvement could be achieved by combining l0 ard lp to joint predictors, with a strongly increasing foehn probability for increasing lp aad decreasing 10.