The Uncertainty of Thunderstorm Nowcasting and its Use in Weather Avoidance Modeling

Weather related uncertainty is a major disturbing factor in accurate aviation route planning. Adverse weather itself impacts the planning process but may be overcome if weather forecasts or nowcasts are used. Knowing that no forecast is perfect, a residuum remains between a forecast for a certain time and the real weather at that time. Assuming that the forecast represents the best knowledge about the future development, deviations from it can be interpreted as the current inherent uncertainty of the forecast. We focus on thunderstorm nowcasts for the next hour using the DLR Rad-TRAM nowcasting system. We analyze the nowcast error, respectively the uncertainty with forecast time and analyze the spatial deviations of nowcast and observed thunderstorm extension. It will be shown how that uncertainty influences the deviation route finding based on our weather avoidance model DIVMET. Animations illustrate the optimum tactical route finding in the presence of thunderstorms and the related uncertainty.