This second tornado in the Newmarket area was 100 metres wide and tracked for 9 kilometres. Trees were snapped and uprooted and damage occurred at a factory; part of its roof was removed and a heavy steel shipping container in the yard was moved and deposited on a stack of irrigation pipes.
Figure 1 depicts the surface observations at 8:00 pm EDT, which shows a cold front slicing through the Great Lakes. Pre-frontal storms developed in southern Ontario in the form of a cluster of storms (Figure 2), which ultimately led to two tornadoes in Newmarket and Cedar Valley.
Figure 2 shows the Doppler radar reflectivity at 10:10 pm moments before the tornadoes developed near Newmarket.
According to Environment and Climate Change Canada (2018), an F1 tornado touched down at 10:15 pm near Cedar Valley, ON. The tornado travelled for 8.84 km with a maximum width of 100 metres. The tornado caused no fatalities, injuries or property damage.
Sources
NWS Weather Prediction Center Surface Analysis Archive. (2017). Surface analysis 00Z Tue Jul 18 2006. Retrieved from: https://www.wpc.ncep.noaa.gov/archives/web_pages/sfc/sfc_archive.php
Environment and Climate Change Canada Data. (2018). Canadian National Tornado Database: Verified Events (1980-2009) – Public. Retrieved from: http://donnees.ec.gc.ca/data/weather/products/canadian-national-tornado-database-verified-events-1980-2009-public/