Description and verification of the NCAR integrated turbulence forecasting algorithm (ITFA)

An automated method for improved forecasting of upper level clear-air turbulence is described. In this method several atmospheric turbulence diagnostics are integrated with available observations to produce the forecast. A verification exercise was performed over the winter 98-99 season in which probabilities of yes and no detections were determined by comparisons to pilot reports (PIREPs). The sparseness and qualitative nature of pilot reports produces some unavoidable uncertainty in the verification results; nonetheless, preliminary results indicate the automated algorithms are competitive with turbulence forecasts produced by knowledgeable human forecasters.