Analysis of Two Turbulence Forecast Indices Using Pattern Recognition And Eddy Dissipation Rate

The purpose of this study is to assist and improve the verification process of the Graphical Turbulence Guidance (GTG) product currently in use by the Aviation Weather Center (AWC). One of the components of the GTG algorithm involves the incorporation of the Eddy Dissipation Rate (EDR). EDR is an in situ measurement in units of turbulent kinetic energy and is based on a transformation of the observed vertical acceleration to obtain a measurement of atmospheric turbulence that is independent of aircraft characteristics and motions. An improved method to utilize Eddy Dissipation Rate (EDR) is described. A qualitative analysis involving five distinct synoptic-scale upper level wind patterns was conducted from 29 significant turbulence events over a four-month study period. It is the goal of this research to determine if any synoptic-scale patterns are better predicted than others using this approach correlating predicted Ellrod and Ellrod-Knox indices used by the Graphical Turbulence Guidance (GTG) with EDR data. Since real-time EDR data are not available to operational forecasters at the AWC, it is hopeful that this study will assist in real time evaluation of the intensity and duration of ongoing and predicted turbulence events and further improvements in forecast algorithms.