Deutscher Wetterdienst - Germany
This talk investigates a low pressure system which occured over the Western Mediterranean and the Balearian islands on 10-11 November 2001. It was associated with a storm and heavy rainfall which caused loss of human life and severe damages on the islands. For instance, on Mallorca maximum wind speeds of more than 150 km/h were observed.
This Mediterranean cyclone was well forecasted by the Lokal-Modell (LM) of the Deutscher Wetterdienst (DWD). LM is a non-hydrostatic mesoscale weather forecast model that is used at DWD for operational 48h-forecasts three times a day. Although the forecast of the cyclone was overall satisfying there is a tendency for overdeveloping the cyclone in the analyses and forecasts. This cyclone shall be used as a test case to investigate how the forecasts evolve the closer the start time gets to the event. The influence of an increased vertical and/or horizontal model resolution is tested. Local details of the precipitation and maximum wind speed as well as the role of convection are investigated.
For this study a different model domain than the operational one is used because the latter does not cover the entire region of interest. The experiment domain is centered around the Western Mediterranean. Since no LM assimilation is done here, the initial state for LM, as well as the boundary conditions, are interpolated from the global forecast model GME of DWD. In a companion paper by H. Frank the early warning capabilities of GME for the case of the same cyclone are assessed.