B.C.'s cold snap could have positive effects going into spring, experts say

The cold snap and high amounts of snowfall currently blanketing B.C. may have long-term benefits for the province, according to experts.

Environment Canada has issued extreme weather warnings for most of B.C. on Thursday, with up to 30 centimetres of snow expected in Metro Vancouver and 25 centimetres on Vancouver Island.

The cold weather, which has been affecting the province for more than a week, has led to transit disruption and dangerous wind chill levels.

Experts, however, say the accumulated snow could have positive effects for the province as winter turns into spring in a few months.

"Snow is vitally important to the region — not just in Metro Vancouver, but throughout the province," said Peter Marshall, a field hydrologist with the regional district of Metro Vancouver.

Metro Vancouver's snowpack — accumulated snow at higher elevations — ends up feeding the watersheds, the area's main drinking water supply.

Marshall said last spring and summer, which saw record-breaking drought in many parts of the province, proved the importance of snowpack from the previous winter.

"We had above average snow throughout the entire [2020] season," he said. "Fortunately, we had enough snow to keep the reservoirs relatively full [in 2021], and there was enough drinking water to last through the dry summer."

Metro Vancouver has more than 2.4 million residents, whose water supply is derived from three reservoirs — Capilano and Seymour in the North Shore, and Coquitlam in the Tri-Cities.

According to Marshall, the region uses approximately 1.5 billion litres of water daily, and he estimates that 200-300 billion litres of water were in the snowpack as of a Jan. 1 measurement.

"Part of that this year is the fact that we've got snow right down to sea level and quite a bit of it, which is quite unusual," he said. "Right now, we're looking like we're in good shape for 2022." 

Though Marshall says drinking water levels are likely secure for 2022, he still urged residents to conserve water, saying there was not enough capacity to store the huge amounts of precipitation that the Lower Mainland receives.

Snow could help wildfire season

Fire ecologist Robert Gray said the snow currently falling on the province could lessen the impact of the 2022 wildfire season, but the persistence of the snowpack — how long it will last — will have a bigger impact than the actual amount of snow.

"If we do have a kind of lingering snowpack that hangs around for a while, it keeps the fuels moist," he told CBC News. "Then it can start to shorten the fire season."

"But if it comes off very quickly in the spring, with most of the climate change models suggesting that we're going to see quicker snowmelt in the spring, then it really doesn't matter how much we get."

Gray says the 2017 and 2018 wildfire seasons, respectively the second-worst and worst wildfire seasons on record in B.C., both had above-average snowpack levels in the Interior that quickly melted.

In addition, he says heavier snowpack could lead to more vegetation growth, which could actually worsen the impact of fires as grass becomes drier and turns into fuel.

However, he thinks the early arrival of cold weather in B.C. could help quell the impacts of a potential mountain pine beetle infestation.

"When [the beetles] become epidemic, they kill lots and lots of trees," Gray said.

"We need really cold temperatures early in the winter kind of October and November to basically freeze and kill the larvae. If we get colder temperatures later, it doesn't always have the same effect."