29. The Storm Prediction Center (SPC) highlighted a large portion of the western Great Lakes in a slight risk of severe weather as a weak cold front slowly drifted through the area.
Later in the afternoon, the SPC issued a mesoscale discussion (#709) that highlighted most of Wisconsin as likely to experience some strong winds and hail.
Surface dewpoints were high and there was good instability, but the shear was expected to remain weak enough to limit the severe threat.
Temperatures across the northern half of the state were in the 70s with dewpoints in the 60s. A few areas had brief sunshine which helped to boost temps and create a bit more instability.
Unfortunately, I was in a meeting all afternoon and missed most of the excitement. I was able to hear thunder and capture some radar screenshots after the storms moved out over Lake Superior, which I'll post below.
I took this screenshot from GR Level3 at 15:32 local time. Outlined in red boxes are severe thunderstorm warnings for northern Bayfield County and the Apostle Islands, central Gogebic County, and most of Ontonagon County, both in the UP of Michigan.
Hail was the primary threat from these cells as they moved northwards, with radar detecting the possibility of up to 1" in diameter hail.Also visible on this screenshot is a lake-effect breeze around the Twin Ports (Duluth/Superior) and northern Douglas County. In addition, the outflow from the storms created another visible line on radar, that moved northwest ahead of the cluster. This outflow interacted with the lake-breeze to produce cells ahead of the main cluster over Bayfield County.
Vertically Integrated Liquid (VIL) is an estimate of how much water is suspended in the storm. This is an image of the VIL as the storm cluster pushed across Chequamegon Bay and moved into the northern section of the Bayfield Peninsula. I've added my location (WBRW3) to the map for reference.
The possible hail core stayed between the city of Washburn and Maple Hill. No damage was reported from my area, but the threat was definitely there, especially considering there was hail and damage reported hours earlier from these storms.
Damage began in Marathon County and progressed northwards, through northern Wisconsin and the UP, survived across Lake Superior, and moved through the Arrowhead of MN before reaching the Canadian border.
The list I put together is actually from north-to-south, which is the opposite of chronological order. So read it from the bottom, up :)
Trees and power lines down were the worst reports, but hail up to 1" in diameter also pounded certain regions. This was the first severe thunderstorm warning for Maple Hill (WBRW3), and with some luck, we'll have more excitement throughout the summer!