Clipper or chinook? How Alberta's most famous weather phenomena impact Canada
Alberta Clippers and chinooks are different, but often occur simultaneously.
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If you feel like this winter has been a weather roller-coaster, you aren't alone.
From mild and melting to snowstorms to -10 C and really windy, the fluctuations seem to come out of nowhere. But in fact, this everything-but-the-kitchen-sink sort of prairie weather is often the result of the dreaded Alberta Clipper.
Sound ominous? Well, let's demystify the term.
What is an Alberta Clipper?
The Alberta Clipper is another name for a storm. It's called that because of where it forms and how fast it moves.
These low-pressure systems, or storms, develop on the east side of the Rocky Mountains and they speed along like a clipper ship on the ocean. (Hence the name.) As they sail across the prairies, these systems can affect weather in Ontario and the eastern United States.
Alberta Clippers typically develop in the winter and can bring wild, rapid swings in the weather. What you see depends on where that low is positioned relative to you.
As the clipper develops in Alberta, we're in what is known as the warm sector and will often see balmy weather.
But when that cold front passes, things start to change.
The wind will pick up out of the north or northwest, ushering in a rapid change from mild weather to cold temperatures and aggressive wind chills.
Because these storms move so fast, we'll often see all of these conditions within a day or less.
What are the biggest risks with clipper systems?
You may think that the worst part of a clipper is the snow, but these systems are usually on the drier side. The bigger problem is the wind.
They can cause white-out or blizzard conditions by whipping up any snow that fell while the clipper moved through, and drive extreme wind chills as temperatures plunge after the system has passed.
Are they the same as a chinook?
A chinook and a clipper system are different but often connected.
Chinooks refer to the warm winds that rush down the east side of the Rocky Mountains.
Warm Pacific air travels over the mountains, cooling and losing a lot of moisture. The resulting relatively dry air rushes down the east side, compressing and warming up at a faster rate before blowing into areas, like Calgary, that border those mountains.
So while chinooks aren't storms, they can bring extremely windy weather and cause temperatures to rise by 10 or even 20 degrees.
Chinooks can form at the same time as clippers, which brings us back to how they're related.
With a clipper's formation, a system in the Pacific weakens and forms again on the east side of the Rocky Mountains.
When that disturbance moves over the Rockies and forms the low-pressure system that will be the Alberta Clipper, we often see the wind travelling over the mountains from the west, allowing for a chinook in the south.
So while one may not cause the other, they often go hand-in-hand.
What will climate change mean for these weather patterns?
When we are looking at climate change and circulation or weather patterns, it's not a simple science.
Here's what we know.
As our weather warms, we can expect more evaporation. That could lead to more moisture associated with clipper systems, meaning more precipitation with them.
As for other factors, it gets a little muddy.
Some experts believe that as the Arctic warms faster than the rest of the world, the jet stream could become more variable, which could mean these systems will track differently or even move slower.
Russell Blackport, a research scientist with Environment and Climate Change Canada, says it's almost impossible to predict how atmospheric circulation will react to a changing climate.
"It's difficult to tell from observations because there is a lot of variability from year to year and even decade to decade," he said.
Blackport said that a warming Arctic and changes in our wind patterns could happen together — not necessarily because of each other but hand-in-hand like the clippers and chinooks.
That being said, the Alberta Clipper isn't going anywhere. We will still see them every year, keeping us on our toes with the wild swings of our winter weather.
Our planet is changing. So is our journalism. This story is part of a CBC News initiative entitled Our Changing Planet to show and explain the effects of climate change and what is being done about it.
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