Today's trend in probabilistic weather forecasting is toward utilizing ensemble prediction systems. In the Next Generation Air Transportation System (NextGen), ensemble-based weather forecasting will be a common practice. Therefore, this paper explores a novel approach of using highresolution, ensemble-based numerical weather prediction model data for weather-related, probabilistic aviation impact forecasting. The concept represents a paradigm shift from "creating ensembles of weather information" (e.g., maps of predicted weather hazard intensity) to "developing ensembles of aviation-relevant information" (maps of potential throughput as measured by the available flow capacity ratio), which entails a translation of weather forecasts into predictions of reduced airspace capacity. The proof-of-concept is exemplified by focusing on convective storms; however, in principal, the approach may be applicable to other aviation hazards, like turbulence, icing, or ceiling and visibility. The concept is most pertinent to strategic en route traffic flow management, but it also applies to terminal area applications. A probabilistic approach is appropriate for strategic planning horizons, for which deterministic weather forecasts are significantly less accurate and an ensemble of forecasts may provide guidance about the weather (and impact) uncertainty.