This tornado struck near the community of Swift Rapids, to the southwest of Gravenhurst, at around 3:30 pm. It tore a 30m wide track through the forest along the shoreline of the Severn River, causing tree damage that earned it its EF0 rating. Area residents reported seeing the funnel cloud and eyewitness video shows a white cone, fully condensed to the ground, passing through the forest.
This was one of two tornadoes to touch down on July 1. The other:
Figure 1 depicts the surface observations at 11:00 am EDT, which shows a strong low pressure occluding across Lake Michigan with an occluded front across southern Ontario. This front was the focus for thunderstorm activity in the early afternoon hours of March 16th, which ultimately led to two tornadoes across southern Ontario.
Sources
NWS Weather Prediction Center Surface Analysis Archive. (2017). Surface analysis 15Z Wed Mar 16 2016. Retrieved from: https://www.wpc.ncep.noaa.gov/archives/web_pages/sfc/sfc_archive.php