We present a new method of clear-air turbulence (CAT) forecasting based on the Lighthill-Ford theory of spontaneous imbalance and emission of inertia-gravity waves. A scale analysis of this theory for mid-latitude synoptic-scale flows identifies advection of relative vorticity as the leading-order source term. Second-order terms including the Jacobian, divergence-vorticity product, and cross-product of velocity with the gradient of divergence may also play non-negligible roles for situations in which Ro < 1 but not Ro << 1. Examination of these leading- and second-order terms appears to help explain the utility of previous, more empirically inspired CAT forecast diagnostics. We then combine the Lighthill-Ford theory with the TKE approach of McCann to create a dynamically consistent, easily implemented and operationally superior CAT forecasting approach.