The FAA's weather architecture will play an important role in the modernization of the NAS, as weather information services are critical to both the safety and efficiency of the NAS. According to the National Research Council (NRC) report on Aviation Weather Services, from 1988 to 1992 one-fourth of all aircraft accidents and one-third of fatal accidents were weather-related . The FAA Aviation Capacity Enhancement plan for 2000 reveals that from 1996 to 2000, adverse weather was still a major factor adversely affecting NAS capacity contributing to 71 percent of system delays greater than 15 minutes. To mitigate these safety and efficiency constraints, aviation weather capabilities in the NAS must undergo major changes.

The FAA began making needed changes two years ago by fielding the second stage of the Weather and Radar Processor (WARP) system, a weather 'server' and workstation for the Center Weather Service Unit meteorologists at the Air Route Traffic Control Centers and Air Traffic Control Command Center. Later this year, the FAA begins implementing its terminal weather 'server', the Integrated Terminal Weather System (ITWS). ITWS will provide valuable products not requiring meteorological interpretation to traffic management specialists at 46 of the busiest NAS airports. The NAS weather architecture continues to evolve in meeting the growing needs of users. It includes improved gridded weather data and new systems providing improved weather products to enhance the performance of decision support systems for controllers and traffic managers. The weather architecture will exploit evolving FAA telecommunications infrastructure enabling near real-time access of weather data to NAS operational decision-makers (i.e., pilots, controllers, traffic managers, flight service specialists, and dispatchers), enhancing situational awareness of weather hazards and facilitating collaborative decision-making which allows timely planning [instead of reacting] to hazardous weather.

The FAA continues to explore new capabilities to provide improved weather services. Emerging capabilities vary from improving weather services to enhance safety at a mid-sized airport to enhancing air traffic operations in a large region of the country requiring coordination among the FAA Command Center, several FAA Centers, and airline dispatchers. For the latter, severe weather in the air traffic corridor extending from Chicago to Boston delays can have a 'ripple' effect throughout the NAS and poses a major challenge for FAA traffic managers. To ascertain the weather services requirements for these two dissimilar situations, the FAA is conducting a concept evaluation with two programs-the Medium Intensity Airport Weather System (MIAWS) and the Corridor Integrated Weather System (CIWS). MIAWS provides tailored weather products traffic control personnel at medium-sized airports utilizing NEXRAD and wind/wind shear data. CIWS will ingest weather data from a mix of FAA and NWS radars as well as lightning data to provide short-term forecasts of storm location and movement.

The NAS weather architecture will continue to meet emerging needs for weather services through FAA-funded applied R&D to improve the detection and forecasting of aviation weather hazards. Thus, the FAA's weather architecture will evolve to meet the needs of the NAS operational decision makers.