Marine Hail · Lake Michigan

Hail up to the size of golf balls was reported at the Northwest Michigan Horticultural Research Center near Bingham, MI; additional reports of hail up to the size of half dollars in downtown Traverse City, MI.

An unseasonably hot and humid air mass in place across the Midwest led to the development of storms late on the evening of the 20th across the Northern Plains. These congealed into a thunderstorm complex over the Upper Midwest, tracking eastward along the perimeter of a strong upper level ridge, into the Upper Great Lakes on the morning of the 21st. A NW-SE oriented broken line of storms developed along a warm advection axis ahead of the initial line of storms; this produced hail up to the size of golf balls across parts of northern Lower Michigan, including the Traverse City metro area. Meanwhile, the original complex of storms began to wane in intensity, becoming a strong mesolow, which crossed Lake Superior during the morning hours and resulted in significant water level changes and attendant coastal impacts across the entirety of Lake Superior.