A Model for Predicting the Movement of Continuously Propagating Convective Storms

The predictions of propagation velocity made by a linear model of moist convective instability are compared with actual case studies of severe local storms. Excellent agreement between observation and theory is found for a certain class of storms, namely those that propagate in a continuous fashion. The calculations suggest that such storms take the form of convectively forced internal gravity waves. The pattern of low-level convergence provided by the gravity wave organizes the convection, which in turn drives the wave.