Aviation weather systems such as the Corridor Integrated Weather System (CIWS) provide weather products and forecasts that aid en route traffic managers in making tactical routing decisions in convective weather. However, it can be difficult to derive the full benefit of convective weather products due to the complexity of air traffic management in a rapidly changing convective weather environment. Automated decision support tools that determine the regions of airspace blocked by convective weather and estimate the impact of convective weather on scheduled traffic can reduce the effort needed to formulate and implement strategies that mitigate the impacts of convective weather.

Two recent studies [1, 2] present models that estimate the probability of pilot deviation around convective weather in en route airspace as a function of location and flight altitude. Weather Avoidance Fields (WAFs) calculated using these models may be used to determine which regions of airspace are likely to be passable. However, models to predict pilot behavior are very difficult to validate, since pilot intent must be inferred using only flight plans and actual trajectories. A recent study [3] illustrates the difficulties and limitations of attempting to infer pilot intent. Furthermore, observed flight trajectories may not correctly represent pilot preference. In some instances, pilots may have penetrated airspace that they would rather have avoided or they may have avoided airspace that was easily passable.

It is desirable to replace the inference of pilot intent with an objective measure (e.g., turbulence, lightning, hail, etc.) of airspace penetrability in the validation of WAFs. In this study, WAFs are validated by comparing the deviation probabilities encountered along flight trajectories to in situ turbulence measurements. Turbulence measurements were obtained from two sources: two flight missions flown by instrumented aircraft in and around thunderstorms in the upper Midwest, and in situ turbulence measurements from instrumented commercial aircraft [4]. On-board weather radar images, video, photographs and pilot narrative from the cockpit were also obtained from the flight missions. These data are also compared to the WAF probabilities and turbulence encountered along the flight trajectory.