Three July 24 tornadoes confirmed in QC
NTP investigation, including ground/drone surveys, has resulted in three tornadoes being confirmed associated with the storms in southern Quebec on the evening of July 24. All tornadoes were weak, with ratings of EF1 at Brossard (SE of Montreal) and EF0 at Boucherville (E of Montreal) and at Cap-Santé further east. The Montreal-area tornadoes occurred along the leading edge of a quasi-linear convective system (QLCS) while the Cap-Santé tornado occurred with a supercell thunderstorm.
More details are available in the event summaries below, along with maps and damage photos. The tornadoes can be plotted on a map using the NTP Dashboard .
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Event Name: Cap-Santé, QC
Date: July 24, 2024
Estimated Start Time: 7:05 PM EDT (2305 UTC)
Final Classification: Tornado (over land)
Preliminary EF-Scale Rating: EF0
EF-Scale Damage Indicator / Degree of Damage: C-T/DOD-3
Start of damage track: 46.7240N, 71.8090W
End of damage track: 46.7314N, 71.8069W
Location of worst damage: 46.7248N, 71.8090W
Description: Damage was reported at a farm property north of Cap-Santé after a storm passed through the area. A play structure was lofted, a fuel tank toppled and trees snapped along a narrow path. No injuries were reported. A limited area of clear satellite imagery has been reviewed and additional weak tree damage is visible north of the farm property in Saint-Basil-Station. Preliminary damage assessment is EF0 tornado, with estimated max. wind speed of 115 km/h and track length of 850 m. Information available at this time insufficient to accurately estimate max. path width. Tornado motion was from the S (approx. 190 degrees). Start time is radar based. Further satellite imagery review will be complete when clearer imagery is available.
Event Name: Boucherville, QC
Date: July 24, 2024
Estimated Start Time: 7:55 PM EDT (2355 UTC)
Final Classification: Tornado (over land)
Preliminary EF-Scale Rating: EF0
EF-Scale Damage Indicator / Degree of Damage: FR12/DOD-2
Tornado damage location: 45.5787N, 73.4256W
Description: Witness captured video of a tornado in Boucherville. No damage and no injuries were reported. An NTP ground and drone survey of the area was completed on July 26, 2024, where weak roof damage to a home was discovered and homeowners also reported weak tree damage occurred. Preliminary damage assessment is EF0 tornado, with estimated max. wind speed of 100 km/h. Information available at this time insufficient to accurately estimate track length, max. path width and tornado motion. Satellite imagery review is pending.
Event Name: Brossard, QC
Date: July 24, 2024
Start Time: 8:11 PM EDT (0011 UTC)
Final Classification: Tornado (Over Land)
Final EF-Scale Rating: EF1
EF-Scale Damage Indicator / Degree of Damage: SBO/DOD-6
Start of damage track: 45.4250N, 73.4651W
End of damage track: 45.4644N, 73.3811W
Location of worst damage: 45.4476N, 73.3999W
Description: Witnesses captured video of a tornado in Brossard, where tree damage and toppled semi-trailer was reported. The truck driver suffered minor injuries. An NTP ground and drone survey was completed on July 25-26, 2024. The team documented the reported damage and discovered additional damage to structures (including a barn and homes) along the tornado path that ended in the Brookline neighbourhood of Longueuil. Damage assessed as EF1 tornado, with an estimated max. wind speed of 135 km/h, track length of 8.03 km and max. path width of 110 m. Tornado motion was from the WSW (approx. 240 degrees). Start time is based on witness report. Satellite imagery review is pending.
Regional map showing the locations of the three tornadoes in Quebec from July 24.
Drone photo a house in Boucherville with a tarp covering the area where many roof shingles were removed. Some light tree damage was also reported in this area and had been mostly cleaned up. As this was the only location with damage a survey map was not created.
Survey map for the Brossard EF1 tornado showing the track to the NE and the locations of ground and drone photos.
Drone image of a destroyed barn, the worst damage found along the Brossard tornado track. The walls had collapsed after the roof was removed. Debris from the barn was found up to 600 m to the NE.
Drone photo of a shipping container that was tossed through a fence by the Brossard tornado.
Drone photo showing the path of the Brossard tornado through an area of long grass.
