The areas affected include... Lake Superior from Saxon Harbor WI to Upper Entrance to Portage Canal MI 5NM off shore to the US/Canadian border including Isle Royale National Park...
At 822 AM EDT, Doppler radar indicated a strong thunderstorm, capable of producing winds to around 30 knots and small hail. This thunderstorm was located 20 nm southeast of Rock of Ages Light, or 34 nm northeast of The Western Lake Superior Buoy, moving east at 25 knots.