Melting ice may be delaying spring
Extreme weather could signal ‘fundamental change in our weather’
Scientists suspect that not enough winter in the Arctic has led to too much of it across the rest of Canada. From Toronto, where ice storms cancelled baseball games, to Calgary, where residents this week faced yet another heavy snowfall warning, April 2018 has come to feel like endless winter.
Some climatologists say this is the future — long stretches of freakishly unseasonable weather that flip to something else on a dime.
“It was looking like it was going to be the warmest December on record in Western Cana- da,” said David Phillips, Environment Canada’s chief climatologist.
“Then it turned on you — several days of -30 C. It was from one extreme to the other.”
Why? Icy Arctic air is normally held back by a strong, highaltitude, west-to-east river of air called the jet stream.
The jet stream is powered by the temperature difference between the Arctic and mid-latitudes.
But the Arctic is warming faster than anywhere on Earth, especially this year, when temperatures at the North Pole were up to 30 degrees above normal.
That weakens the jet stream. And that, said Rutgers Univer- sity climatologist Jennifer Francis, is the problem.
“When the jet weakens, it tends to take these bigger north and south swings,” she said.
“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.”
Hence, ice storms in April.