Studies on data uncertainties of the local model of the German Meteorological Service in the catchment area of the river Ilm
Résumé
The forecast data were investigated comprehensively in order to quantify the statistical reliability. Therefore, the 2nd moment as the case may be the standard deviation of the differences between observed precipitation values and forecasting precipitation values have been calculated. The investigations were subdivided into the complete stretch of time, the hydrological summer and the hydrological winter. Each measured value was analysed with regard to the 12-, 24-, 36- and 48-hour forecast made by the DWD.
As a result, empirical analytical functions were developed to describe adequately the statistical quantities for standard deviation of precipitation and temperature for the periods of hydrological summer and hydrological winter in dependence on forecasting time, mean ground level and roughness (fractal dimension) of the LM-grid cell.