A determination of whether rural areas east of 黑料社入口 were struck by a tornado will depend on what kind of evidence emerges in the next few days.聽
Photographs, patterns of destruction, and any eyewitness accounts of funnel clouds will all be considered to see if the Highway 33 corridor was struck by what would be an unusual but not unprecedented weather event for the mountainous area.聽
鈥淲e can neither confirm nor deny it was a tornado at this point,鈥 Ken Dosanjh, an Environment Canada meteorologist, said Friday in an interview. 鈥淲e don鈥檛 have any information to say conclusively, and we don鈥檛, typically, until a ground survey is done.鈥
Nearby weather stations reported winds of 80 km/h, and a radar-based weather system recorded peak winds in the Highway 33 corridor of 90 km/h, Dosanjh said.聽
But tornadoes, of course, are not just a function of windspeed. There has to be a violently rotating column of air that touches the ground, and the phenomenon itself may or may not be visible, according to the U.S. National Weather Service.聽
鈥淭ornadoes develop extremely rapidly, and may dissipate just as quickly. Most tornadoes are on the ground for less than 15 minutes,鈥 the NWS says on its website.聽
In Canada, tornadoes are most common on the Prairies and parts of Central Canada, Dosanjh said, where geography and climate allows for the combination of necessary events.聽
鈥淥bviously, we don鈥檛 get many tornadoes in B.C. compared to our Prairie partners,鈥 he said, though he added one was confirmed in the Lower Mainland in November 2021.聽
鈥淭ornados are more prevalent over flat terrain where they can actually begin to rotate and gather speed. It gets fuzzier in mountainous terrain, where these perfect vortices are less likely to occur,鈥 he said. 鈥淚t would be pretty rare, I would say, for a tornado to develop in that area, especially since we鈥檙e well into meteorological fall at this point.鈥
A key factor in the development of tornadoes, he said, is extreme wind sheer, which is when wind is moving at different speeds depending on the elevation. Warm, moist air is also necessary, which is why tornadoes most commonly happen in the summer.聽
On Wednesday, several all-time temperature records were set in the B.C. Southern Interior. Creston hit 31.7 C, and it was above 30 C in Nakusp and Nelson.聽
鈥淗ot temperatures are definitely an additional factor in the formation of tornadoes,鈥 Dosanjh said. 鈥淎long with the warm air, you get extra heating from the ground itself, which helps to create a more unstable atmosphere.鈥
After-the-fact evidence of a tornado can include such things as large swaths of downed trees, as opposed to sporadic damage, Dosanjh said. A path of destruction that鈥檚 relatively long and narrow would also be a sign, as would evidence of debris being thrown in multiple directions from a damaged house or outbuilding.聽
Anyone with pictures or accounts of the unusual weather phenomenon can email them to Environment Canada for evaluation at聽pacificstorm@ec.gc.ca聽or post them on X with the hashtag BCStorm聽
