Some updates on the 2022 ON-QC derecho
Here are a few new updates from NTP's continuing investigation of the 21 May 2022 derecho that caused widespread wind damage in Ontario and Quebec.
Maximum observed wind gust
We obtained the raw files for the weather stations along the path of the derecho, and we were able to recover a wind gust to 147 km/h at Region of Waterloo International Airport. The previous maximum gust there was 131 km/h. As can be seen in the figure below, there were three consecutive peaks in the wind gust data at the airport, with the first being 131 km/h and the second being 147 km/h - the highest observed gust with the derecho event overall.
Graph of wind gusts at the Region of Waterloo International Airport
associated with the derecho. Data points are at five second intervals.
Wind speeds are in km/h, time is in UTC. Data courtesy of NAV CANADA.
Fatalities
Fatality and injury information related to the derecho has been hard to come by. The NTP thoroughly examined media reports and determined there was at least 12 unique fatalities (11 in Ontario, 1 in Quebec) and 12 unique injuries (all in Ontario). More recently, we worked with the Office of the Chief Coroner of Ontario to determine that there were another 4 related fatalities in that province. This brings the count to 15 in Ontario, and 16 fatalities overall. Most were caused by falling tree branches. We have been unable to determine if additional injuries occurred.
Insured Losses
According to NTP partner CatIQ, their final industry loss assessment indicates that there was $1.217B in insured losses attributed to the ON-QC derecho. This makes it one of the most (if not the most) costly natural disasters in Ontario recorded history, one of the costliest natural disasters in Canadian recorded history, and certainly the costliest wind-related event ever recorded in Canada. Note also that uninsured losses are typically several times the value of insured losses.
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