Waves in a cloudy vortex

Starting from first principles we present a system of equations that approximately govern small amplitude perturbations in a non-precipitating cloudy vortex. The model is used to study moist vortex Rossby wave dynamics analytically and computationally. It is shown that, by reducing buoyancy, moisture can hinder the growth of phase-locked counter-propagating vortex Rossby waves in the eyewall of a hurricane-like vortex. It is also shown that moisture can (indirectly) damp discrete vortex Rossby waves that would otherwise grow and excite spiral inertia-gravity wave radiation from a high Rossby number cyclone. The possible relevance of our results to hurricane intensity theory is briefly addressed.