THE PREDICTION OF SURGES IN THE SOUTHERN BASIN OF LAKE MICHIGAN

Abstract

A summary of numerical computations is presented, in a form designed to aid in operational prediction of surges in the Southern Basin of Lake Michigan. The computations are based upon a dynamical model in which the surge is generated by pressure gradient and wind stress in a squall line which moves across the Basin with constant speed and direction. For each of 25 combinations of squall-line propagation speed and direction, the arrival time of the surge is determined, and the amplitude estimated, at various locations along the shore. At some locations there are a well-defined peak of surge amplitude and corresponding critical values of squall-line propagation speed and direction, associated with resonant coupling between the squall line and Lagrangian body waves. Energy computations indicate the presence of another resonant peak associated with Stokesian edge waves.