Convective weather avoidance modeling for low-altitude routes
May 31, 2011
Thunderstorms are a leading cause of delay in the National Airspace System (NAS), and significant research has been conducted to predict the areas pilots will avoid during a storm. An example of such research is the Convective Weather Avoidance Model (CWAM), which provides the likelihood of pilot deviation due to convective weather in a given area. This report extends the scope of CWAM to include low-altitude flights, which typically occur below the tops of convective weather and have slightly differentoperational constraints. In general, the set of low-altitude flights include short-hop routes and low-altitude escape routes used to reduce the impact of convective weather in the termnial area. For classification, low altitude flights are identified as either deviations or non-deviations, and the corresponding weather features are analyzed. Precipitation intensity is observed to be the best predictor of deviation in the low-altitude flight regime, as compared to the differenc ein altitude between the flight and the echo tops for en route flights. Additionally, the low-altitude CWAM performs better than the departure CWAM currently used in the Route Availability Planning Tool (RAPT) when tested on deterministic weather data.