Storm with Two Faces: Why typhoon-fueled B.C. storm differed
Sunday, October 16, 2016, 9:17 AM - The third in a series of powerful and fatal storms pushed through B.C.'s South Coast Saturday evening, enhanced by tropical moisture from the remnants of former Super Typhoon Songda.
But, naturally, small-scale deviations resulted in variable outcomes, with some residents seeing a destructive storm and others feeling that the impacts "under-delivered" for areas in the forecast.
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The storm resulted in tens of thousands of power outages while delivering damaging winds of 80 to 110 kilometres per hour -- trees and power lines were uprooted or pushed over, damaging homes and leading to several road closures.
But slight digressions in track kept the wind fields just northwest of Vancouver, causing these severe conditions to strike within a limited area.
"After Friday’s deadly storm, this storm quickly became frustrating for forecasters from Portland, Seattle, and B.C offices -- including us here at The Weather Network," says Weather Network meteorologist Tyler Hamilton.
"It was forecast to reach a very deep low pressure, but models didn’t have the best handle the wind field and the complicated terrain effects of the South Coast also added to the chaos."
The wind field didn't spread as far into the Lower Mainland as expected, so the Gulf Islands took the brunt of the system, with power outages still pending repair along the Sunshine Coast Sunday morning.
A small track digression of about 30 kilometres caused Point Atkinson to see wind gusts of nearly 100 km/hr while leaving Vancouver International Airport with less than 70 km/h.
The hardest-hit areas were Vancouver Island, the Gulf Islands, and the Sunshine Coast.
"Many people [were] calling this a 'bust,' while others tweeted howling winds and tree limbs falling," says Weather Network meteorologist Erin Wenckstern. "[It was a] different storm for many people, [but] we are extremely fortunate that the worst case scenario didn’t evolve for the Lower Mainland."
What would the worst-case scenario entail? For starters, many more power outages. There was minor flooding in low-low lying areas around Boundary Bay, but Hamilton says things could've been significantly worse.
"The ground was saturated, so if those gusty winds would have pushed onshore more damage was expected," Hamilton notes. "This is one of the times we’re relieved the wind forecast didn’t verify, because the track was very reminiscent of some of the Pacific Northwest’s most powerful low pressure systems."
As always, Hamilton says the biggest challenges in weather forecasting remains in conveying uncertainty.
"Given the possibilities I saw with model solutions the best course of action was followed. Bottom line, there will always be a certain level of unpredictability in weather."
What's ahead for this typhoon-enhanced system?
Much of this system's energy has pushed into the Prairies, fueling a dynamic set-up with freezing rain, snow, and showers to the south, Hamilton says.
Meanwhile, the trough in B.C. will migrate back toward where it is commonly found during this time of the year: in the Gulf of Alaska.