Publications

The purpose of this manuscript is twofold. First, it provides a review of the activities of the Weather Evaluation Team (WET), which is part of a joint Industry and Federal Aviation Administration (FAA) effort called Collaborative Decision Making (CDM). Over ten years ago, the predecessor to the WET, the Weather Action Group (WAG), developed a process that involved industry and government participants in the production of the Collaborative Convective Forecast Product (CCFP). The CCFP was developed in response to the need of industry and government Air Traffic Managers to have a common forecast of convective information used in their decision making processes. In light of the concepts introduced by the Next Generation Air Transportation System (NextGen), the CCFP could be viewed as one predecessor to the Single Authoritative Source. During the period 2008 through 2010, the WET worked on a task to increase the amount of detail as well as extend its forecast time period. At the same time, new automated convective forecasts were developed and introduced to both the WET and Traffic Flow Management (TFM) community. The manuscript includes a description of how the WET has strived to integrate both Human-in-the-Loop (HITL) and fully automated products, including the Localized Aviation Model Output Statistics (MOS) Product (LAMP)/CCFP Hybrid (LCH), the Aviation Impact Guidance for Convective Weather, the Corridor Integrated Weather System (CIWS) and the Consolidated Storm Prediction for Aviation (CoSPA). The second purpose of this manuscript is to introduce the new concept called Operational Bridging. The WET first discussed Operational Bridging at the 2010 Friends and Partners of Aviation Weather (FPAW) Vision Meeting in July, 2010. Foundational materials such as a Concept of Operations (CONOPS) and a demonstration plan are now being developed by the WET. Operational Bridging is first described from within a meteorology-centric view of the CCFP forecast process. Not only does this allow the new concept to be further defined, it also lays out a transition path for the current CCFP. Operational Bridging is next described from the broader conceptual perspective of Air Traffic Management (ATM)/Weather Integration, and two key areas are explored: 1) the role of the CDM weather community in the area of automated probabilistic and deterministic convective weather forecast information and 2) the integration of probabilistic forecast information into both strategic and deterministic (tactical) ATM decision making process.

Convective storms pose a significant threat to aviation safety, and often result in substantial fl ight delays for the commercial aviation industry. The overall impact of these storms is typically based on thunderstorm climatologies and are often one of the factors used in decisions by the US government regarding the operational benefits and allocation of its weather surveillance resources. These climatologies are based on the average number of days that a thunderstorm is observed at a particular airport. Due to the nature of the criteria used to identify a thunderstorm, the climatological statistics often do not accurately represent the number of thunderstorms that impact an airport's operations. The present study utilizes data from the Dallas Ft. Worth International Airport (DFW) and the Orlando International Airport (MCO) to identify deficiencies in the climatological data as it applies to aviation applications. A spatially representative climatology is presented as a more accurate climatology for use in evaluating the impact of convection on an airport's operations. This type of climatological estimate of thunderstorm frequency significantly increases the estimated number of thunderstorms impacting an airport and their associated costs.

Low level wind shear has been identified as an aviation hazard which has caused or contributed to a significant number of aircraft accidents (Soffer, 1990). To protect aircraft from hazardous wind shear, the Federal Aviation Administration (FAA) developed a system called the Low Level Wind Shear Alert System (LLWAS), containing a collection of anemometers as well as data processing logic (Wilson and Gramzow, 1991). The LLWAS has undergone several advancements in both design and algorithmic computation. The latest deployment, known as the Network Expansion Low Level Wind Shear Alert System (LLWAS-NE), consists of additional sensors to the original LLWAS network, providing better coverage of the airfield. In addition, the LLWAS-NE is capable of providing runway-oriented wind shear and microburst alerts with loss and gain values. The alerts from LLWAS-NE will be integrated with those from the Terminal Doppler Weather Radar (TDWR) and the Integrated Terminal Weather System (ITWS) at locations where all systems are available (Cole, 1992; Cole and Todd, 1994). An analysis was undertaken at Orlando (MCO) and Dallas/Ft. Worth (DFW) International Airports to assess the accuracy of wind shear alerts produced by LLWAS-NE and the TDWR/LLWASNE integration algorithm. Identifying improvements that can be made to either system is important, as LLWAS-NE alert information is anticipated to be integrated with ITWS in an ITWS/LLWAS-NE integration algorithm. As currently specified, the ITWS/LLWAS-NE integration algorithm will work the same as the TDWR/LLWAS-NE version. The ITWS/LLWAS-NE algorithm is an area where additional work is necessary to ascertain if the integration parameters should be modified to account for performance differences between the ITWS and TDWR algorithms. We suggest that ongoing assessment of the LLWAS-NE should use both LLWAS-NE data and TDWR base data, when possible. Comparing both data sets also will facilitate optimization of LLWAS-NE parameters used in the computation of the alerts.