Surface weather observations and barograph traces from the region surrounding the Great Lakes were analyzed for the hours 0300 to 1300 cst, August 3, 1960. Synoptic and time-section analyses of the surface weather show the squall line which moved across the southern part of Lake Michigan between 0900 and 1000 cst. An isochrone analysis of the pressure jump also is presented.
Records from several water-level recording gages in the Southern Basin of Lake Michigan are transcribed, and show clearly the surge which was produced by passage of the squall line over the Lake.
From transit times at eight stations in the region surrounding the Southern Basin, the average speed and direction of motion of the squall line have been determined. Lake-level data for the surge caused by the squall line of August 3, 1960, are compared with the lake levels computed by Platzman for a squall line moving with similar speed and direction.