On Tuesday afternoon, 06 August 2013, a supercell thunderstorm moved across central Minnesota into western Wisconsin and produced a long swath of severe weather. A supercell is a very strong thunderstorm that has a rotating updraft. They are able to sustain themselves for several hours, and produce large hail and damaging winds. A radar loop shows the storm as it moved across the region. Numerous storm reports were received just south of the I-94 corridor. As the pictures below show, this storm caused extensive damage to crops and vehicles. Several storm spotters reported hail 2 inches or greater.
Above: The loop shows the base reflectivity of the storm that started in western Minnesota and moved southeast across the Twin Cities metro area before falling apart as it moved into western Wisconsin. The radar images are approximately every 10-15 minutes. The storm is highlighted by the white circle.
Below: This storm produced a long swath of large hail just south of the I-94 corridor. A radar estimated track of the severe hail is shown in the left hand image, while the right hand image shows the actual reports that were received at the National Weather Service office in Chanhassen MN.
The top left image shows the supercell thunderstorm as it was approaching Wright County. This storm had already produced baseball size hail (top right). The storm still looked impressive as it moved through the metro area (bottom left) and large hail knocked the windows out of several cars.
The storm reports are listed below.