NEWS

Canada's tornado season slower than normal, Environment Canada says

08/05/2015 12:49 EDT | Updated 08/05/2016 05:59 EDT
It has been a slow year for tornadoes in Canada, Environment Canada reports.

That's despite a spate of recent tornado reports – including a "monster,"three-hour tornado in Manitoba and another in Ontario that smashed buildings and uprooted trees — and at least one prediction that we might get more tornadoes than usual this year, thanks to El Nino.

So far this year, says Peter Kimbell, warning preparedness meteorologist with Environment Canada, there have been just 15 tornadoes confirmed across Canada:

- 4 in Alberta.

- 1 in Saskatchewan.

- 6 in Manitoba (including water spouts).

- 4 in Ontario.

"It's been a quiet year not only for tornados, but severe storms," Kimbell told CBC News Wednesday, adding that tornadoes tend to peak in July.

"We're kind of already past the peak of the year."

In Canada, an average of 60 tornadoes are reported each year, and tornado season generally runs from June to August. Tornadoes are "detected" based on eyewitness reports and photos, as they are too small to measure remotely.

In fact, says Kimbell, past averages are probably underestimated because most of those reports come from a time before everyone constantly carried a cellphone with a camera.

"We're a lot better equipped to know when they do occur [now] than we used to be."

Heat and moisture required

He says the unusually low number of tornadoes has to do with this year's summer weather in the Prairies and Ontario – the regions that see the most tornadoes.

"The conditions required to produce a tornado are pretty unique and pretty difficult to attain," he said.

Those conditions include  lots of heat and lots of moisture.

Ontario has seen fairly normal summer temperatures, Kimbell said.

While warmer-than-average temperatures on the Prairies have helped fuel massive wildfires, he added, "I would not say it's been outstandingly hot and it certainly hasn't been hot and humid."

Tornadoes are very difficult to detect and predict because they're extremely small compared to storms or other weather patterns that meteorologists typically track.

Up until now, twisters could only be predicted a few days ahead of time, but scientists are just beginning to try and predict whether there will be more or fewer tornadoes than usual in a given season.

El Nino effect?

A U.S. scientist recently predicted that Canada might have a busier tornado season than normal because it's an El Nino year. El Nino is the name given to warmer-than-normal ocean temperatures in the equatorial Pacific, which can affect weather patterns in other parts of the globe.

In Canada, El Nino typically changes the position of the jet stream – an air current in the upper atmosphere that has a big influence on the weather in Canada - and leads to warmer than normal temperatures, says Johanna Wagstaffe.

However, she said Canada hasn't really seen much of an effect yet from El Nino.

"It has been a slow start to the year for tornadoes because the jet stream was in this 'stuck' pattern for so long – keeping the west hot and dry and keeping the east cool and soggy," she said in an email.

She noted, though, that meteorologists at the U.S. National Oceanic and Atmospheric Administration (NOAA) are now predicting a strong El Nino for this winter and spring.

"The pattern is changing as El Nino takes hold," she said. "Hard to say if it will impact this year or we have to wait until next spring and summer to see the effects."

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