Extensive tree damage resulted from this F1 tornado that occurred about 40km to the north of Ear Falls near Gerry Lake. Its track was 2 km long and 600 metres wide, resulting in swath of damage through the forest. This was one of four tornadoes that touched down on August 16, 2011.
Figure 1 depicts the surface observations at 4:00 pm EDT, which shows an occluding low pressure in northern Manitoba, bringing a cold front near the ON/MB border and a warm front in northwestern Ontario. The warm front became the focus for intense thunderstorms throughout the afternoon and evening hours, which ultimately led to four tornadoes across northwestern Ontario on this day.
NWS Weather Prediction Center Surface Analysis Archive. (2017). Surface analysis 21Z Tue Aug 16 2011. Retrieved from: https://www.wpc.ncep.noaa.gov/archives/web_pages/sfc/sfc_archive.php