Bonnyville was hit with one of the strongest windstorms in recent years last week, with gusts of over 100 kilometres an hour leaving a trail of damage through the region.
In the early hours of Wednesday morning, a low-pressure system from the Northwest Territories was moving southeast in Saskatchewan and Manitoba, sucking in a “bunch of warm air” from the Pacific Ocean, according to Environment Canada meteorologist Dan Kulak. From there, that system hovered over much of Alberta, wreaking havoc throughout most of the province.
In Lac La Biche, winds reached a high of 104 kilometres per hour, while St. Paul recorded highs of 96 kilometres per hour and Cold Lake saw winds of 93 kilometres per hour. Winds in Lloydminster topped out 107 kilometres per hour, according to Environment Canada.
Although there were no actual records set in Bonnyville, Kulak said it was safe to assume that winds in the town surpassed the 100 kilometre per hour mark.
In town, there were several issues and accidents caused by the strong winds – with shingles being torn off roofs, the roof of a cabin near Moose Lake being blown off, and several signs in town either being blown completely over and lost, or, as was the case with the Muller Plaza sign, blown so that it sat on a slant. Northern Lights School Division also cancelled its school bus service that day.
Although the storm took those in town completely by surprise, both in terms of its strength and longevity, Kulak said they do occur “somewhat regularly.”
“These systems, I'm not sure I'd say they are common, but we do get them from time to time. However, the strength and longevity of this storm was somewhat unusual,” Kulak said. “This probably is not out of the realm of what we're used to getting with summer thunderstorms – the interesting thing with this system was that it was such a widespread event (two thirds of the province was affected) and the strong wind gusts didn't just last three minutes, they lasted hours.”
He added, “The peak wind strength in a storm is one thing, but it's the gusty nature of winds that often causes a lot of damage, and they don't typically last that long. You can have a structure that is built to withstand 100-kilometre an hour winds, but once we start to see gusting, those are more powerful and that's when we start to see things moving around and causing lots of damage. I think the gustiness of wind is often overlooked by most people and somewhat underrated.”
La Crete, a hamlet in northern Alberta, saw the highest winds, with gusts reaching 130 kilometres an hour. Elsewhere, in Slave Lake, winds topped out at 126 kilometres an hour. Kulak also noted that there were several temperature records broken for this time of the year on Wednesday, with Cold Lake setting a new record of 9.1 degrees Celsius, surpassing the old record of 5.7 set last year.
“It's definitely been a long time since we've seen weather and winds like this, but it really can happen whenever and wherever,” Kulak said. “So people need to be taking precautions and ensure they are protecting themselves and their properties from the dangers that come with storms like this, because they can form at a moments notice.”