Application of Probabilistic Convective Weather Forecasts for Flight Routing Decisions

Abstract

An available probabilistic convective weather predicts probabilities of severe weather occurrence in the continental United States up to a six-hour period. This paper examines the forecast for making flight routing decisions. By synchronizing the forecast with air traffic data in a simulation, the intensity and ceilings of the forecasted weather are used to derive a cut-off probability value, which represents the bounding probability contour that aircraft are most likely to avoid. This parameter is an important metric for meteorologists in improving the accuracy of weather forecasts from an air traffic management perspective. The cut-off parameter for this forecast product was computed as 35% for a one-hour forecast, over a three-month period during summer of 2007. The results are shown for different altitude levels, aircraft types and airspace users. Using this parameter, a method of calculating flight distances and times, while avoiding specific areas of convective activity is presented for flight planning decisions. Several improvements to the forecast weather data, such as frequency, accuracy, and coverage, are suggested to improve the utility of weather data in air traffic management. I. Introduction LIGHT delays in the United States have been steadily increasing with the increase in air traffic. The Federal Aviation Administration’s (FAA) Operational Network (OPSNET) data show that during the two four-month periods from May through August of 2005 and 2006, weather related delays accounted for about 70% of all reported delays. The current deterministic weather prediction in tactical (within the next 2 hours) timeframe is at a manageable level of accuracy; however, the state of weather forecasting for strategic (2-6 hours) time frame needs improvement for longer-term flight planning. 1 In the absence of weather forecasts with sufficient accuracy, the decision-making for flights longer than two hours is challenging. The Joint Planning and Development Office working on Next Generation (NextGen) Air Transportation System considers weather-assimilated decision-making a principal area of research. The NextGen Weather Integrated Product Team has considered integrated weather information and improved aviation weather forecasts as two of the main efforts for future development.