Four ON waterspouts on August 10/11
The NTP has confirmed four waterspouts in Ontario on August 10 and 11. Three waterspouts occurred in eastern Ontario over Lake Ontario (2) and the St. Lawrence River (1) on August 10. Another occurred over Lake Nipissing in northeastern Ontario on August 11. The waterspouts did not appear to make landfall. Given they caused no damage, they have been assigned an EF0-Default rating. There were more reports of potential waterspouts and we will continue to investigate these.
A few related reminders. Waterspouts are simply defined as tornadoes over water. For NTP's purposes, if the tornado spent its entire lifetime over water, it is classified as a Tornado (over water). Any tornado that spends at least part of its lifetime over land is classified by NTP as a Tornado (over land).
Full details are provided below along with a regional map. The tornadoes can be plotted on a map via the NTP Dashboard .
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Event Name: L Ontario (Brighton), ON
Date: August 10, 2024
Start Time: 10:00 AM EDT (1400 UTC)
Final Classification: 2 x Tornadoes (Over Water)
Final EF-Scale Rating: EF0-Default
Estimated Tornado Locations: 43.72N, 77.78W / 43.72N, 77.74W
Description: A witness captured a photos of two concurrent waterspouts over Lake Ontario south of Brighton. No damage was reported. Event time is based on witness report.
Event Name: St. Lawrence River (Gananoque), ON
Date: August 10, 2024
Start Time: 12:10 PM EDT (1610 UTC)
Preliminary Classification: Tornado (Over Water)
Preliminary EF-Scale Rating: EF0-Default
Estimated Tornado Location: 44.32N, 76.11W
Description: Witness captured photos of a waterspout over the St. Lawrence River in the Thousand Islands area (near Gananoque). No damage was reported. Satellite imagery review of the shoreline is pending. Event time is based on witness report.
Event Name: L Nipissing (North Bay), ON
Date: August 11, 2024
Start Time: 6:45 PM EDT (2245 UTC)
Preliminary Classification: Tornado (Over Water)
Preliminary EF-Scale Rating: EF0-Default
Estimated Tornado Location: 46.29N, 79.56W
Description: Witness captured video of a waterspout over Lake Nipissing near North Bay. No damage was reported. Satellite imagery review of the shoreline is pending. Event time is based on witness report.
Regional map showing the three locations of the four waterspouts, each having an EF0-Default rating.
