FAA Terminal Convective Weather Forecast Algorithm Assessment

Predicting convective weather is extremely important to aviation, since thunderstorms are the largest cause of national airspace delay. Accurate 1-hour convective weather forecasts meet critical terminal traffic planning needs of the TRACON and ARTCC supervisors and traffic managers, as well as airline dispatchers and pilots.

The Terminal Convective Weather Forecast (TCWF) product has been developed by MIT Lincoln Laboratory as part of the FAA Aviation Weather Research Convective Weather Product Development Team (PDT). Lincoln began by consulting with air traffic personnel and commercial airline dispatchers to determine the needs of aviation users. Users indicated that convective weather, particularly line storms, caused the most consistent problems for managing air traffic. The "Growth and Decay Storm Tracker" developed by Wolfson et al. (1999) allows generation up to 1-hr forecasts of large scale, organized precipitation features with good, and operationally very useful accuracy.

The TCWF has been tested in Dallas since 1998, in Orlando since 1999, and in New York since FY2000 began. These have been informal demonstrations, with the FAA Technical Center assessing utility to the users, and with MIT LL modifying the system based on user feedback and performance analyses. The TCWF is now ready for a formal Assessment. Ultimately, the FAA Technical Center will judge whether TCWF is suitable for inclusion in the FAA's operational Integrated Terminal Weather System, which has an unmet requirement for 30+ min forecasts of convective weather. The Memphis International Airport has been selected for the TCWF Assessment, since it has not been exposed to the forecast product during prior demonstrations. Operations will begin in early spring, 2000. Operational feedback will be assessed by the FAA Technical Center and MCR Corp. will perform a quantitative benefits assessment.

This paper will describe the current TCWF algorithm, give examples of operational impact of terminal forecasts, and analyze the technical performance of TCWF during the Assessment in Memphis.