The Available Potential Energy Budget of a Severe Storm-Producing Extratropical Cyclone

Abstract

An available potential energy budget analysis is presented for an area and period (0000 GMT 3 April-1200 GMT 4 April 1974) spanning the lift cycle of a severe storm-producing extratropical cyclone which moved across the central United States. Included are diabatic heating estimates. Among these, total latent heat release and longwave radiation contribute significant positive and negative values, respectively. Total latent heat release is generally in good agreement with observed weather features and cyclone development. Budget results show that during the development of the extratropical cyclone the available potential energy within the region under investigation increases. Diabatic generation is a source of available potential energy, but its value is rather small when compared with other budget terms. Available potential energy generation primarily results from convective latent heat release ahead of the cold front in the warm sector. A large amount of total potential energy is released; however, only a small portion is converted into kinetic energy within the system. Horizontal transport of available potential energy is always a significant source of available potential energy.