2018 Ontario–Quebec tornado outbreak
Major damage to apartment buildings in Gatineau, Quebec as a result of an EF3 tornado.
|Formed||September 21, 2018 between approximately 4:40 PM and 6:30 PM;  EDT|
|Tornadoes confirmed||6 |
|Max rating1||EF3 tornado|
|Total fatalities||0 fatalities, 30 injuries|
|Areas affected||eastern Ontario and southern Quebec|
|1Most severe tornado damage; see Fujita scale|
The 2018 Ontario–Quebec tornado outbreak is a severe weather event that affected the region around the National Capital Region of Canada. Six tornadoes have been confirmed, including an EF-3 along a 38 kilometres (24 mi) corridor from Dunrobin, Ontario to Gatineau, Quebec, an EF-2 in Nepean sector of Ottawa, and 4 EF-1. Other damages have been recorded in Eastern Ontario due to downbursts with thunderstorms. No death were recorded but 30 persons were injured.
On the afternoon of September 21, 2018, a localized outbreak of tornadoes impacted eastern Ontario and southern Quebec. During the event, Environment Canada issued numerous tornado warnings as multiple tornadic supercell thunderstorms moved through the area. Between 3:30 PM and 6:30 PM EDT, six tornadoes, two of which were strong, caused damage in and around the National Capital Region of Canada.
The most significant tornado of the event made a direct hit on the small community of Dunrobin in the west end of Ottawa, then crossed the Ottawa River and hit the Mont-Bleu neighbourhood in the Hull sector of Gatineau, Quebec. The Dunrobin-Gatineau tornado was classified as a high-end EF3, with winds reaching 265 km/h.  Approximately 25 people were injured by the EF3 tornado, six of those taken to the hospital and five people had life-threatening injuries. At least 200 buildings were damaged and an unknown number were destroyed along the path.
A second strong tornado caused significant damage in the Arlington Woods, Craig Henry, and Merivale Road neighbourhoods of Nepean and was rated as a high-end EF2 with winds of 220 km/h The tornadoes were preceded by severe thunderstorms throughout Ontario and Quebec. 
Damage from the tornadoes caused 272,000 people in the region to be without power, with some of the outages lasting for days. During the event, the EF3 tornado that struck Dunrobin and Gatineau was visible on the horizon behind the Parliament Hill buildings in Ottawa. A still image of the funnel was also captured from a live webcam.
September 21 event
|EF#||Location||Census division||State||Start Coord.||Time (UTC)||Path length||Max width||Summary||Refs|
|EF3||W of Kinburn to Gatineau||Ottawa, Gatineau||ON, QC||N/A||N/A||N/A||N/A||This destructive tornado touched down in Ontario near Kinburn, heavily damaging multiple homes, destroying barns and outbuildings, and mangling farm machinery. The tornado then struck Dunrobin at high-end EF3 strength, damaging or destroying numerous homes, a couple of which were leveled or swept from their foundations. Vehicles were thrown and destroyed, debris was scattered through fields, and shopping plaza was severely damaged. The tornado maintained EF3 strength as it crossed into Quebec and moved through densely populated areas of Gatineau. Many apartment buildings sustained major structural damage in this area, many of which had their roofs torn off, with some sustaining collapse of their top floor exterior walls. Trees were snapped and debarked, power poles were snapped, and cars were tossed and damaged as well. At least 200 buildings were damaged or destroyed, and 25 people were injured, five critically.|||
|EF2||Nepean||Ottawa||ON||N/A||N/A||N/A||N/A||A rain-wrapped, high-end EF2 tornado touched down in western Nepean and struck the Arlington Woods and Craig Henry neighbourhoods of Nepean, where many homes and apartment buildings were damaged. Some homes sustained roof loss, and a few sustained partial exterior wall failure as well. A church had much of its roof ripped off, and numerous large trees were snapped or uprooted, many of which landed on homes and vehicles. A metal truss tower was toppled over and mangled as well. Further east, a power substation was severely damaged, businesses had their roofs blown off, power poles were snapped, and a box truck was overturned. The Colonnade Road Business Park also sustained considerable damage. Additional trees and tree limbs were downed in the Greenboro neighbourhood before the tornado dissipated.|||
|EF1||Calabogie||Renfrew||ON||N/A||N/A||N/A||N/A||This tornado touched down in Calabogie, snapping and uprooting many trees, causing roof damage to homes, and destroying a garage.|||
|EF1||SE of Val-des-Bois||Papineau||QC||N/A||N/A||N/A||N/A||Many trees were snapped and several buildings were damaged along the path. Homes sustained roof damage, and boats and docks were damaged as well.|||
|EF1||E of Mont-Laurier||La Vallée-de-la-Gatineau||QC||N/A||N/A||N/A||N/A||This tornado tracked through densely forested areas near the Baskatong Reservoir, snapping trees and damaging power lines.|||
|EF1||N of Otter Lake||Pontiac||QC||N/A||N/A||N/A||N/A||A tornado tracked through densely forested areas, downing numerous trees along its path.|||
- CONFIRMED: Two tornadoes, one downburst hit Ottawa region, The Weather Network, September 22, 2018
- Tornado warning issued for Ottawa-Gatineau area, CBC News, September 21, 2018
- https://ottawacitizen.com/news/local-news/tornado-101-the-science-behind-the-twisters%7Ctitle=Tornado aftermath: The science behind the twisters|newspaper=The Ottawa Citizen|date=2018-09-23|access-date=2018-09-24}}
- "Tornado hits Ottawa-Gatineau area, damaging buildings and flipping cars | CTV News". Retrieved 2018-09-22.
- "Updated: 'It's devastating': Tornado levels houses, leaves trail of destruction". 22 September 2018.
- "Tornado tears through Ottawa and Gatineau area, causing injuries | The Star". thestar.com. Retrieved 2018-09-22.
- "Tornado destroys homes, hydro poles in Hunt Club and Greenbank area - CBC News".
- Inc., Pelmorex Weather Networks. "'Dynamic fall storm' slams Quebec with severe weather". The Weather Network. Retrieved 2018-09-22.
- "At least 2 tornadoes touch down near Ottawa; about 272,000 without power in Ontario and Quebec". Global News. Retrieved 2018-09-22.
- Here's how the Ottawa-Gatineau tornadoes formed so quickly, Global News, September 24, 2018
- Tornado strikes were 'luck of the draw,' says meteorologist, CBC News, September 23, 2018
- "6 tornadoes hit Ottawa-Gatineau region, Environment Canada says | CBC News". CBC. Retrieved 2018-09-26.
- Map of where the six tornadoes touched down in Ottawa-Gatineau areas on September 21, 2018, CBC News, September 25, 2018
- UPDATE: Officials increase Friday's tornado count to SIX, The Weather Network, September 26, 2018
- "Here's where power is out across the region - CBC News".
- Kalvapalle, Rahul. "Ottawa residents could be without power for days after tornado devastates Hydro One station". Global News. Retrieved 2018-09-22.
- Chianello, Joanne. "When is the power coming on? Not for days". CBC News. Retrieved 22 September 2018.
- The sky does not look good, Twitter, September 21, 2018
- Live shot of Parliament Hill downtown Ottawa right now. Tornado warned storm cell tracking north of downtown towards Gatineau, Kelly Sonnenburg TWN/trendsmap.com, September 21, 2018
- Third tornado at Calabogie and White Lake is confirmed by Environment Canada, Ottawa Citizen, September 24, 2018
- Environment Canada confirms 3rd tornado hit Calabogie, White Lake, insideottawavalley.com/Renfrew Mercury, September 25, 2018
- "In Arlington Woods, tornado cleanup begins amid 'ripped apart' buildings - CBC News".
- "Egan: Overlooked in Calabogie — the F1 tornado that escaped limelight". 25 September 2018.
- "Environment Canada confirms 3rd tornado hit Calabogie, White Lake". 25 September 2018.