Mesoscale spiral vortex embedded within a Lake Michigan snow squall band: high resolution satellite observations and numerical model simulations

Abstract

An exceptional and often neglected source of data for mesoscale cloud studies is the ultrahigh resolution multispectral data produced by Landsat satellites. On 19 October 1972, a clearly defined spiral vortex was noted in a Landsat-1 image near the southern end of Lake Michigan during an exceptionally early cold air outbreak over a still very warm lake. In a numerical simulation using a 3-D Eulerian hydrostatic primitive equation mesoscale model, with an initially uniform wind field, a definite analog to the observed vortex was generated. This suggests that intense surface heating can be a principal cause in the development of a low-level mesoscale vortex. -from Authors