Millgrove, ON EF1 Tornado of August 2, 2015

City of Hamilton


This EF1 tornado struck the community of Millgrove in northwest Hamilton, damaging trees and houses. It touched down at about 10:00 pm, with a path that was 1.7 km long and 200m wide.

https://twitter.com/tidridge/status/628248012842758144?s=20

Many trees were snapped and uprooted, and others left standing had large branches torn off and thrown. Several houses suffered minor damage but, at one property, a section of the home’s roof was removed. In addition, a fabric gazebo was torn apart, its metal frame twisted and destroyed, and a municipal salt dome was demolished.

This was one of four tornadoes that touched down on August 2, 2015. The others:

  • Teviotdale (EF2)
  • Lebanon (EF2)
  • Marsville (EF1)
Figure 1. Surface analysis at 03Z on August 3, 2015 showing mean sea-level pressure (MSLP) contours, surface observations, fronts and pressure centres (WPC, 2017)

Figure 1 depicts the surface observations at 11:00 pm EDT, which shows a squall line (line of thunderstorms) moving across southern Ontario and Lake Ontario. This line of storms was responsible for several strong tornadoes across southern Ontario in the late-evening hours of August 2nd.

Figure 2. Doppler radar reflectivity at 10:43 pm EDT (source: https://meteologix.com/ca)

Figure 2 shows the squall line moving across the GTA in southern Ontario.


Sources

NWS Weather Prediction Center Surface Analysis Archive. (2017). Surface analysis 03Z Mon Aug 3 2015. Retrieved from: https://www.wpc.ncep.noaa.gov/archives/web_pages/sfc/sfc_archive.php