178 TRANSLATING AN ENSEMBLE WEATHER FORECAST INTO OPERATIONAL DISRUPTION FOR THE NATIONAL AIRSPACE SYSTEM John Huhn*, Michelle A. Duquette The MITRE Corporation, McLean, VA David R. Bright DOE, Bonneville Power Administration, Portland, OR Jonathan P. Racy, Gregory H. Grosshans NWS Storm Prediction Center, Norman OK Brad Sherman FAA ATCSCC, Herndon VA 1. INTRODUCTION Thunderstorms are responsible for many air traffic delays across the National Airspace System (NAS) each year. They are also considered a threat to aviation safety due to their ability to produce both en route and terminal weather-related hazards such as lightning, hail, turbulence, microburst’s, and wind shear. The Federal Aviation Administration (FAA) plans traffic flows to avoid thunderstorms utilizing a 6 hour forecast product designed for aviation. The MITRE Corporation’s (MITRE) Center for Advanced Aviation System Development (CAASD) analyses have demonstrated that thunderstorm impact to the NAS can be forecast reliably well beyond 6 hours and even up to 72 hours before the event in some cases. However, available forecasts are not useable to FAA traffic managers because they are designed for meteorologists and do not depict traffic flow impact. MITRE is partnering with the FAA’s Air Traffic Control System Command Center (ATCSCC), and the National Oceanic and Atmospheric Administration (NOAA)/National Weather Service (NWS)/Storm Prediction Center (SPC) and Aviation Weather Center (AWC), to develop a prototype forecasting capability that shows a greater than 6 hour forecast thunderstorm effect on traffic flows. This work supports Next Generation Air Transportation System (NextGen) weather integration initiatives set forth by the Joint Planning and Development Office’s (JPDO) documentation titled: Air Traffic Management (ATM) Weather Integration Plan version 1.0. (JPDO 2009) The primary objective for this collaborative research effort is to provide the FAA with a reliable aviation centric convective weather forecast for timescales greater than 6 hours. In doing so, the research has demonstrated the ability to correlate a meteorological *Corresponding author address: John Huhn, The MITRE Corporation’s Center for Advanced Aviation System Development, Mailstop N590, McLean, VA 22102; e-mail: jhuhn@mitre.org ; forecast with historical air traffic demand, producing a unique aviation weather forecast capability. This prototype capability allows traffic managers to view forecasted impact to aviation from thunderstorms, not the thunderstorm forecast itself. The capability requires no meteorological interpretation by the end user and provides a longer range planning horizon for the FAA and its customers. Longer range adverse weather impact information enables all stakeholders to plan their operations to make the best of available resources. With longer lead times, the FAA can request and have a greater opportunity to obtain the use of available resources they do not control such as Canadian or military airspace. Longer lead times also allow the FAA’s customers to plan for complex logistics such as fleet and crew assignments. This paper describes the collaborative research effort that resulted in the development of longer range convective weather forecasts tailored to the aviation community. It additionally includes a proposal for use in the Traffic Flow Management strategic planning process. 2. INITIAL RESEARCH The basis of this research stems from MITRE observations and analyses from the operations floor at the ATCSCC. Those analyses showed that some convective events could be forecast up to 3 days before an event using longer range weather products such as the Storm Prediction Center’s Convective Weather Outlook. Conclusions from that research were provided in the form of recommendations suggesting that a longer-term planning approach is feasible and should be considered by the FAA for implementation (Duquette et al. 2007). 3. COLLABORATIVE EFFORT The purpose for the FAA, MITRE, SPC and AWC collaboration was to develop a way to provide useable and longer-range convective weather forecast information to FAA flow managers. Over the past few years, MITRE has made several visits to the SPC and