Civil and Environmental Engineering Publications

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Bulletin of the American Meteorology Society

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Canada is a vast country with most of its population located along its southern border. Large areas are sparsely populated and/or heavily forested, and severe weather reports are rare when thunderstorms occur there. Thus, it has been difficult to accurately assess the true tornado climatology and risk. It is also important to establish a reliable baseline for tornado-related climate change studies.

The Northern Tornadoes Project (NTP), led by Western University, is an ambitious multidisciplinary initiative aimed at detecting and documenting every tornado that occurs across Canada. A team of meteorologists and wind engineers collects research-quality data during each damage investigation, via thorough ground surveys and high-resolution satellite, aircraft and drone imaging. Crowdsourcing through social media is also key to tracking down events. In addition, NTP conducts research to improve our ability to detect and accurately assess tornadoes that affect forests, cropland and grassland. An open data website allows sharing of resulting data sets and analyses.

Pilot investigations were carried out during the warm seasons of 2017 and 2018, with the scope expanding from the detection of any tornadoes in heavily forested regions of central Canada in 2017 to the detection of all EF1+ tornadoes in Ontario plus all significant events outside of Ontario in 2018. The 2019 season was the first full campaign, systemically collecting research-quality tornado data across the entire country. To date, the Project has found 89 tornadoes that otherwise would not have been identified, and increased the national tornado count in 2019 by 78%.

© 2020 American Meteorological Society

Citation of this paper:

Sills, D. M. L., and Coauthors, The Northern Tornadoes Project - Uncovering Canada’s True Tornado Climatology. Bull. Amer. Meteor. Soc., doi: (retreived from

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