Environment Canada meteorologist Armel Castellan says the extreme weather the Sunshine Coast has been battling the last two months is the result of “celestial bodies.”
“For this particular year, we're dealing with these dates in the middle of the month, kind of matching the full moon. And so that's the start of the event,” he said. “Every year this happens, we get the highest astronomical tides. It's when the celestial bodies, the moon, the sun and the Earth are all in alignment, and we happen to be closest to the sun, which is counter intuitive, because it's our winter, but we're facing away from it, so that's why we have winter, but we're also closest to it. And therefore, when we have the right situation, we end up getting the worst-case scenario.”
On Saturday Dec. 14, the Sunshine Coast was once again rocked by extreme winds and king tides, sometimes known as “astronomical tides,” in some areas along the Coast. The storm caused power outages across the Coast and in a press release that same day, BC Hydro said almost 300,000 customers lost power between the Lower Mainland, Sunshine Coast, Vancouver Island and the Gulf Islands.
By 9 p.m. that same night, nearly 265,000 customers had their service restored with another 39,000 on the Coast and Lower Mainland without power overnight. By Dec. 15, most customers had their power restored after crews worked throughout the night.
As well, some ferries were cancelled Dec. 14, out of the Langdale Terminal, including all of the New Brighton (Gambier Island) and Keats Landing (Keats Island) routes, as the result of “high winds and unfavourable sea state in the Strait of Georgia.” Morning ferries between Powell River and Blubber Bay (Texada Island) were also cancelled.
Across the Coast, some boat rigging snapped, washing watercraft onto beaches or leaving them adrift. High tides and winds also displaced personal watercraft, such as kayaks and canoes, where they were stored on local beaches in Sechelt, while some picnic tables were swept into the ocean. In some cases, fallen trees closed roads, including in Pender Harbour.
“The thing about storm surges or coastal flooding, is that it's one thing to get to a high astronomical tide, you know, those are the quote, unquote, spring tides that happen every at this time of the year,” said Castellan. “And then you need to have low pressure, which of course, allows for the water levels to rise just because there's less air pressure above it. And so that's important. And finally, you need, what are called low-pressure systems.”
Combine that with the “gradient of the wind, and then that's a combination,” says Castellan.
“That's a kind of the worst-case scenario, because if the wind is strong and it's coming from the wrong direction then, of course, you get the wind up, the waves run up the shore and that's when that quote, unquote, sea agitation makes all the difference. Because often, if the water levels are super high, but it's calm, then that's fine. You've got high tide and it's just kind of gentle and it comes back down. But when there are winds, wind and waves, then you can get yourself into some possible damage.”
Castellan noted these extreme weather patterns are not common to the Sunshine Coast and added, for example, the Nov. 4 wind event, which caused massive power outages and road closures due to fallen trees, did not actually reach warning levels.
He explained it was all of those forces coming together at the same time that caused that storm to reach such power.
“It just happened to have a convective storm or a thunderhead go through Sechelt or near Sechelt, and that's when that tornado was created. It got deemed an EF-zero, which is the weakest kind, but it's still a November tornado.”
He added, tornadoes are very rare on the Coast and the last one witnessed in BC, was on Nov. 6, 2021 which hit at UBC, just prior to the devastating atmospheric river, which cause a loss of human and animal life, massive damage, flooding and wiped-out part of the Coquihalla Highway.
“But this is new territory from that perspective, because we just don't generally have tornadoes at any time. If you're on the Coast, it's quite rare. So, to see that was pretty impressive,” he said.
Castellan explained the situation could have been much worse this past weekend but because the winds and waves peaked at 11 a.m. and high tide was at 2 p.m., the two didn’t have the opportunity to converge and cause peak damage.
“But if that surge element had been later during that time, maybe 2:30 [p.m.], that would have been more problematic. So, you would have added another 20 centimetres on that size. So, you got a bit of a break there,” he said. “But it’s all relative, if there was actual damage, that person or the people involved in the damage of their property might feel otherwise. But yeah, it can usually always be worse.”
Speaking of “worse,” Castellan said bomb cyclones are “incredibly formidable” and while the Coast recently survived two of them, if they had been situated over land rather than water, the devastation could be beyond anything anyone could expect.
“I mean, they rival hurricane-force winds, but they typically need to occur over water. Now, the day that those storms make landfall will be a historic day, because it’s already impactful enough to see upwards of 300,000 people without power in B.C. alone, mostly on Vancouver Island and parts of Vancouver on the mainland coast and the Sunshine Coast,” said Castellan. “And I think there were 690,000 people without power in Washington State. So, it's a big event. You know, close to a million people on the Pacific Northwest and B.C. Coast without power.”
He noted if a bomb cyclone was to hit over land, we’d likely experience gusts of more than 170 km/h.
“Those are hurricane force winds and then some,” he said. “So, it definitely could be worse.”
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