Today weather forecasts assist in the preparation of roads during the winter season to avoid accidents resulting from snow, rain and slipperiness. As with any weather forecast there is always a search for improvement. One way to do this is by verifying the forecasted parameters with the actual weather observed in the forecasted area. To facilitate identification of significant trends and patterns within weather data we have developed an application based on interactive information visualization techniques. The application was created in close collaboration with domain experts from the Swedish Meteorological and Hydrological Institute and initial feedback from a performed user study shows that interactive visualization speeds up the analysis process as well as increases flexibility compared to currently used manual methods.