There are longstanding jokes about Canadian winters, but this year, they feel much less like jokes, as winter seems to be never ending and now scientists warn that the melting Arctic could the root cause.

The ice storms wreaking havoc in Ontario and the snowfall in Alberta this week wouldn’t be altogether uncommon or concerning if not for the fact that it’s April and we’re almost a month into spring.

If that weren’t bad enough, some climatologists are now saying that these patches of unseasonable weather may become the new norm.

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“It was looking like it was going to be the warmest December on record in Western Canada,” David Phillips, Environment Canada's chief climatologist, told the Canadian Press. “Then it turned on you — several days of -30 degrees C. It was from one extreme to the other.”

Ottawa’s warmest day of 2018 was on Jan. 12.

And last weekend, hundreds of flights to Toronto were cancelled, ice fell from the CN Tower and punctured the Rogers Centre, and just days ago one day of snow in Calgary threatened to exceed the city’s monthly average.

Read More: The Arctic Just Had Its Warmest Winter Ever

This winter also saw the East Coast hit with five huge storms in just three weeks, according to the Canadian Press.

What’s happening to Canada’s weather system?

Icy Arctic air is normally restrained by the jet stream, a strong, west-to-east air current. The jet stream is fuelled by the difference in temperature in the Arctic and mid-latitudes. But because the Arctic is warming, the jet stream is becoming weaker.

Read More: Arctic Ice Is Now Floating Around Canada — And Here's What It Means

“When the jet weakens, it tends to take these bigger north and south swings,” Jennifer Francis, Rutgers University climatologist, told the Canadian Press. “When it takes one of these big southern swings, it allows all that Arctic cold air to plunge much farther south than it normally would and it tends to stick around there longer.”

And so — freezing storms rage on in April.

Not all scientists are willing to definitively link melting ice to this unusual weather, but there is evidence building and Francis said at least 15 papers have connected the two.

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“I don't think you'd find a scientist who'd say there's nothing going on. The events that we've seen in the last few years are very consistent with what we'd expect,” she said.

If the Artic ice continues to melt and scientists are right about its results, this kind of weather could be in store for the future.

“It's the preview of what we're going to see. The circulation has changed. It's almost a fundamental change in our weather,” Phillips told the Canadian Press.

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