Accession Number : AD0716811

Title :   The Use of Trajectories in Terminal Forecasting (Second Report).

Descriptive Note : Technical rept.

Corporate Author : AIR WEATHER SERVICE SCOTT AFB ILL

Personal Author(s) : Diercks,John W.

Report Date : NOV 1970

Pagination or Media Count : 33

Abstract : Trajectory forecasting techniques have been introduced at 75 Air Weather Service forecast units. Trajectory data, in the form of parcel origins and forecast temperatures, dew points, and cloud amounts, are transmitted twice daily to these forecast units. These data are a by-product of the Air Force Global Weather Central's (AFGWC) Multi-Level Cloud-Forecasting Model and are used to supplement conventional forecast tools. In addition, 600-meter (above ground level) temperature and dew-point forecasts from AFGWC's Boundary-Layer Model are included in the trajectory bulletin. Trajectory techniques have been integrated subjectively and objectively into forecast procedures with encouraging results. Ceiling and visibility forecasts prepared with trajectory data have verified better than forecasts prepared without trajectory data. This report discusses past evaluation programs, characteristics of the trajectory model, and procedures for using the data in forecast applications. (Author)

Descriptors :   (*WEATHER FORECASTING, NUMERICAL ANALYSIS), MATHEMATICAL PREDICTION, MATHEMATICAL MODELS, AIR MASS ANALYSIS, CLOUDS, ATMOSPHERIC MOTION, VISIBILITY, CEILING, FEASIBILITY STUDIES

Subject Categories : Meteorology

Distribution Statement : APPROVED FOR PUBLIC RELEASE