Application of spontaneous imbalance theory to the problem of clear-air turbulence forecasting

The theory of spontaneous imbalance and emission of inertia-gravity waves based on the work of Lighthill and Ford is used to develop a new method of clear-air turbulence (CAT) forecasting. A scale analysis of this theory for mid-latitude synoptic-scale flows identifies advection of relative vorticity as the leading-order source term for gravity wave activity. Examination of leading- and second-order terms elucidates previous, more empirically inspired CAT forecast diagnostics. Application of Lighthill-Ford theory to CAT forecasting has led to superior forecasts compared to the best operational CAT forecasting methods in existence. We will address the possible physical and dynamical reasons for the success of this application of theory.