Kennisis Lake, ON F1 Tornado of July 15, 1995


This was the first of several tornadoes that touched down in the middle of the night during a fierce derecho that swept across Central Ontario. It had a path that was up to 700 metres wide and 9.2 km long, striking at 2:30 am. Cottagers reportedly described hearing a ‘whooshing sound’ and ‘niagara falls and a freight train combined’ as the tornado tore through.

Dozens of acres of forest were devastated as the tornado tossed trees and branches out into Kennisis Lake. Two large islands were almost entirely deforested, losing over 80% of their trees. In addition, a number of cottages were destroyed, one of which was reported to have looked as though it had exploded. Most of this damage was likely the result of falling trees that smashed through roofs and tore cottages from their foundations as they were uprooted.

Figure 1. Area affected by July 14-15, 1995 derecho (outlined in blue). Curved purple lines represent approximate locations of the gust front at two-hourly intervals. “+” symbols indicate the locations of wind damage or wind gusts above severe limits (measured or estimated at 58 mph or greater). The red dots denote tornadoes (Storm Prediction Center, 2018).

This was one of four tornadoes that touched down in Cottage Country as a violent derecho swept across Central Ontario. The others:

The Forecast

Figure 2. Surface analysis at 0600Z on July 15, 1995 showing mean sea-level pressure (MSLP) contours, pressure centres, surface observations and fronts (WPC, 2017).

Figure 2 depicts the surface observations on the early morning hours of July 15, 1995. According to the Storm Prediction Center (2018), a bow echo was ongoing since July 14th across the Great Lakes region (Figure 1). At the time of Figure 2, storms were located along the cold front in southern Ontario, extending from the low pressure system. This derecho can be seen via the radar loop shown below. Radar imagery loop from Environment Canada’s King City, Ontario radar (Storm Prediction Center, 2018).

Radar imagery loop from Environment Canada’s King City, Ontario radar (Storm Prediction Center, 2018).

“As the bow echo system producing the derecho crossed northern Lake Huron (LH) and Georgian Bay (GB), it grew in scale and severe winds affected a large part of southern Ontario (ON) during the pre-dawn hours of Saturday, July 15th (Figure ##). Some damage occurred in the Toronto metropolitan area near the southern edge of the derecho, and a wind gust to 136 kph (85 mph) was measured at the Buttonville Airport just north of the city. However, the most severe damage, which likely was associated with wind gusts up to 160 kph (100 mph) or more, occurred along a band from the “Cottage Country” east of Georgian Bay to the northeastern corner of Lake Ontario (LO) and adjacent parts of the St. Lawrence River Valley. This swath of damage was associated with the most rapidly moving part of the bowed line, as depicted in the above radar imagery loop from Environment Canada’s King City, Ontario radar. While most of the damage was associated with intense straight-winds, several brief tornadoes occurred in the bowed line. Most were weak, but a strong F2 intensity tornado hit the town of Bridgenorth, destroying a marina and damaging 20 homes” (Storm Prediction Center, 2018).


According to Environment and Climate Change Canada (2018), an F1 tornado touched down at 2:30 am EDT and travelled for 8.7 km. The tornado caused no fatalities, but caused one injury and $2 million dollars in property damage.


Storm Prediction Center. (2018). July 12-13, 1995 Derecho “The Right Turn Derecho”. Retrieved from:

NWS Weather Prediction Center. (2017). Surface analysis 06Z Sat Jul 15 1995. Retrieved from:

Environment and Climate Change Canada Data. (2018). Canadian National Tornado Database: Verified Events (1980-2009) – Public. Retrieved from: