This time last year, residents on B.C.’s south coast were bracing themselves for a major wind storm that would result in power outages, damage to structures, ferry cancellations and even a death on Vancouver Island.
BC Hydro called the Dec. 20 wind storm the “most destructive in history.”
CREST, the communications system used amongst first responders in the Capital Regional District, saw a call volume of 76,738 transmissions on Dec. 20. The same day in 2017, there were 41,433 transmissions according to the CREST annual report.
At its peak, more than 750,000 customers were without power due to the storm, according to BC Hydro. Strong wind gusts of more than 100 kilometres per hour were predicted by Environment Canada at the time with the ability to damage roof shingles and windows as well as toss around loose objects and broken tree branches.
In White Rock, the wind caused a pier to break in two with a person stranded on the far side. The individual was rescued by helicopter.
Armel Castellan, a meteorologist with Environment Canada, said the wind storm was due to many different weather-related factors that had aligned.
“All ingredients need to be there, you need the storm to be increasing in intensity as it reaches the coast,” Castellan said. “The devil is often in the details when it comes to forecasting events.”
This time last year, a low-pressure system tracked across the central part of Vancouver Island, which Castellan said was not typical. A weather pattern made it possible for the low-pressure system to cross over to coastal B.C. rather than die-off in the Gulf of Alaska.
“The events we saw on Dec. 20 were remarkable in that it was almost as bad as it could get,” Castellan said.
While weather patterns may not align in that way often, Castellan said it won’t be the last time a storm like that occurs. He added climate change is the culprit behind more intense weather events such as wind storms with lingering systems and jet streams causing cold patches in July or arctic fronts like the one that hung over the region in February and March of this year.
Castellan said moisture and energy from the sub-tropics are also projected to increase in intensity, which is often associated with winds and heavy rainfall.
“Wind events are likely to continue to permeate our coast,” Castellan said. “The frequency is something that is not yet conclusive but the intensity is and will be something on a shorter time scale.”
Castellan noted that it is important to remember forecasts can look to decades ahead but that forecasting beyond four or five days can be tricky. Details about the Dec. 20 wind storm, for example, were impossible to know until hours before the event due to the “chaotic nature of the atmosphere.”
Gord Horth, General Manager of CREST said the increase in call volume last year was due to things such as downed power lines and an increase in first responder activity. The CREST system was able to handle a larger call volume and will continue to do so with the new system that is being implemented in the region, he noted.
“Dec. 20 was a really busy day for us,” Horth said. “But that’s the advantage of a public safety network, we’re not relying on commercial towers … we have regular electricity and if the power is cut we go to a backup battery system and a generator too.”