Delaware, ON EF0 Tornado of August 11, 2016

Strathroy - Komoka - Western Middlesex County


This tornado touched down briefly at 12:30 pm, with a path that was just 50m in length and 10m wide. It struck the small community of Delaware, southwest of London, causing minor damage to four homes and properties. Two houses had siding ripped off and one had a railing broken and blown around. In addition, a play set was picked up and thrown several metres from one property to the next, and a path was carved through a nearby field of corn.

The tornado was a landspout that formed beneath the rapidly developing updraft of a thunderstorm on the Lake Erie lake breeze convergence zone. Initially it had the appearance of a truncated cone, then became elongated as it stretched and snaked toward the ground. Several area residents were witness to the event, their photos and videos showing a slender, white rope tornado condensing almost fully to the ground. It touched down briefly in the town, lofting a light whirl of debris, before dissipating as quickly as it had appeared.

Figure 1. Surface analysis at 18Z on August 11, 2016 showing mean sea-level pressure (MSLP) contours, surface observations, fronts and pressure centres (WPC, 2017)

Figure 1 depicts the surface observations at 2:00 pm EDT, which shows a stationary front across southern Ontario and an ongoing thunderstorm (marked as a red ‘R’). This ongoing storm in southwestern Ontario was responsible for this brief tornado in the early afternoon hours of August 11th.


Sources

NWS Weather Prediction Center Surface Analysis Archive. (2017). Surface analysis 18Z Thu Aug 11 2016. Retrieved from: https://www.wpc.ncep.noaa.gov/archives/web_pages/sfc/sfc_archive.php