A line of storms (bow echo) passed through Marinette County, WI and Menominee County, MI around 8:30 AM CDT on Tuesday morning, June 19, 2012. As the storms neared the Lake Michigan border, a book-end vortex developed on the far northern extent of the line, causing significant straight-line wind damage across J.W. Wells State Park just south of Cedar River. MI DNR estimates 400 trees down across the park, with the heaviest damage near the park entrance, just off M-35. DNR officials are thankful this storm did not occur during the weekend hours as the park's campground was also heavily hit.
Looking at Green Bay's radar on the image to the left, you can see the line of storms moving to the east during this time (this image was taken at 8:32 AM CDT). You can also see an area of higher reflectivity (red) along the northern edge of the line headed towards J.W. Wells State Park (denoted by the white X). A Google image showing the location of J.W. Wells State Park off M-35 has also been included to the right. Cedar River is just to the north off the screen.
Zooming in near the park...
National Weather Service employee's from the Marquette office visited J.W. Wells State Park to assess the damage and determine the estimated wind speeds. Some of the pictures of the extensive tree damage are included below.