Canadian snowpack gets thinner every decade: Environment Canada study

Much of what used to come down as snow now happens as rain

It may not feel like it the morning after a blizzard, but Canada gets less snow than it used to — a lot less.

That’s the conclusion of scientists at Environment Canada, who have just published what they say is the most precise estimate of global snowfall yet.

“It seems like it should be easy, right? You just stick a ruler in the snow,” said Chris Derksen, a co-author of the study published Wednesday in the journal Nature.

But no.

Unlike rain, snow depth can vary widely over just a few metres depending on factors such as wind. As well, some snow is heavy with moisture and some is dry powder.

And the world’s network for snow observation is sparse, Derksen said. Add to that the difficulty of trying to estimate snow depth from satellite observations and you’ve got the beginnings of what has been a 15-year project for Derksen’s team.

“Snow is a tricky thing to measure,” he said. “We had quite a few data sets that estimated snow mass, but they were based on different techniques and they didn’t agree with each other very well.”

Working with Finnish colleagues, the federal researchers combined satellite data and on-the-ground measurements.

READ MORE: Higher-than-normal snowpacks mean parts of B.C. at risk of flooding

On average, they conclude, the world gets about 3,000 billion tonnes of snow every year.

But that’s not a static number, at least not in North America. Snowfall hasn’t changed much over Eurasia since 1980, but it is declining in Canada and the United States.

Over the last 39 years, snowfall in the two countries has dropped by about 4.6 billion tonnes a year. The paper is silent on how many shovelfuls that is, but Derksen said it’s about enough to fill almost two million Olympic-sized swimming pools with snowmelt.

The steepest drops are in the eastern part of the continent. Parts of the west have actually seen slight increases.

Derksen said regions with less snow aren’t necessarily drying out. Climate change has been shortening the season for a while, and some of what used to fall as snow now comes down as rain.

“The amount of precipitation is not decreasing.”

But snow is a lot easier to manage, he said.

“When (snow) melts, we can manage our reservoir levels and trap that meltwater. As soon as it rains, it runs off in streams.”

That difference has important consequences for big-city water supplies as well as flood threat management. The 2013 Calgary flood is an example of what can happen when unexpected heavy rains come early in the season, said Derksen.

The paper does have its uncertainties. It is unable to say much about snowpack in the mountains, for example.

But Derksen said the work goes a long way to understanding that most Canadian of elements. And it should help managers plan as snowfall changes along with the rest of the climate.

“What this study has tried to do is narrow that uncertainty.”

This report by The Canadian Press was first published May 20, 2020

Bob Weber, The Canadian Press


Like us on Facebook and follow us on Twitter.

Want to support local journalism during the pandemic? Make a donation here.

Climate changeEnvironment Canada weatherNews and WeatherSnow

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

Maple Ridge theatre launches fall season at only 10 per cent capacity

The ACT Arts Centre only allowing 50 patrons at performances due to public safety guidelines

Grinch steals Maple Ridge – Pitt Meadows Christmas Hamper Society’s safe

Theft happened early Tuesday morning at organization’s Albion fairground office

Fire at supportive housing on Royal Crescent

Firefighters find chair on fire, building being evacuated

Canada West Golf Championships cancelled due to COVID-19 travel restrictions

UBC, UBC-O, UFV and UVic athletes will not hit the links this year, Kelowna was set to host

B.C. reports 96 new COVID-19 cases, one hospital outbreak

61 people in hospital as summer ends with election

‘Unprecedented’ coalition demands end to B.C. salmon farms

First Nations, commercial fishermen among group calling for action on Cohen recommendations

Earthquake off coast of Washington recorded at 4.1 magnitude

The quake was recorded at a depth of 10 kilometres

B.C.’s top doctor says she’s received abuse, death threats during COVID-19 response

Henry has become a national figure during her time leading B.C.’s response to the COVID-19 pandemic

Is it time to start thinking about greener ways to package cannabis?

Packaging suppliers are still figuring eco-friendly and affordable packaging options that fit the mandates of Cannabis Regulations

Join Black Press Media and Do Some Good

Pay it Forward program supports local businesses in their community giving

BC Liberals must change gears from election cynicism, focus on the issues: UBC professors

COVID-19 response and recovery is likely to dominate platforms

B.C. could be without a new leader for multiple weeks after Election Day: officials

More than 20K mail-in voting packages were requested within a day of B.C. election being called

Dozens of Canadian venues to light up red in support of entertainment workers

Local facilities among dozens across Canada to participate in Light Up Live

Most Read