Wednesday, 15 May 2002: 1:15 PM
Integrated Turbulence Forecasting Algorithm 2001 Meteorological Evaluation
The Federal Aviation Administration (FAA) Aviation Weather Research Program (AWRP) has sponsored research and development activities aimed at improving the detection and forecasting of Clear Air Turbulence (CAT). The National Center for Atmospheric Research (NCAR) has developed the Integrated Turbulence Forecasting Algorithm (ITFA) as a result of these efforts. ITFA is composed of numerous CAT indices that are calculated using the forecasted fields of the Rapid Update Cycle (RUC) and assigned weighting factors based on turbulence observations obtained from pilot reports (PIREPS). The output and weighing factors are integrated, with the resulting final output displayed as graphical forecasts of CAT. In 2000, the FAA William J. Hughes Technical Center, Weather Branch (ACT-320), performed an event driven meteorological evaluation of the ITFA. Ten turbulence events were identified by utilizing Significant Meteorological Information Advisories (SIGMETs) and PIREPs to identify regions of substantial CAT. Output from ITFA was correlated to these turbulent regions before, during, and after CAT events. In 2001, NCAR made several changes to the algorithm, including decreasing the number of individual indices. ACT-320 conducted additional evaluations which focused on how the current algorithm compared to the 2000 version of ITFA, and on the performance and contribution of the individual indices. The results to be presented at the conference will aid NCAR in further development of the algorithm.