Author: George McLean

Publisher:

Published: 1965

Total Pages: 0

ISBN-13:

This paper discusses a study that was undertaken to investigate the technique of using in-flight temperature gradients to forecast impending clear-air turbulence (CAT) and some recent studies concerning the relationship between jet stream winds and turbulence. Results of the study indicate that a horizontal temperature gradient observed in flight by direct sensing methods is not a conclusive indicator of impending turbulence. However, an improved inflight indicator of CAT is needed. If winds obtained from rawinsondes were to be computed at 2000-ft intervals (or less) at the time of the original reduction of data by operational units, the maximum values of av. wind speed (change of wind direction/change of height) could easily be computed, coded, and transmitted as part of the standard upper-air code transmission in the same way as other special parameters. If the value of av. wind speed (change of wind direction/ change of height) over 2000-ft layers could be computed as described by Kronebach (J. Appl. Meteorology 3:119-125 (1964) and included in the parameters analyzed by the National Meteorological Center, Suitland, Maryland, the writers feel that a substantial improvement could be made to CAT forecasts using rawinsonde data.