The Beauty of a Chinook Arch

The Wayward Wind / Gogi Grant 1956

In Alberta and elsewhere – like Montana and Colorado – we get this weather phenomenon we call Chinooks and Chinook Arches.

Chinook Arch Definition:

A Chinook arch is a striking weather phenomenon often seen along the eastern slopes of the Rocky Mountains—especially around Calgary. It appears as a long, curved band of cloud stretching parallel to the mountains, usually with a sharp, clear boundary. This arch forms when warm, dry Chinook winds descend the mountains and create a high crest of air that shapes the cloud layer into that distinctive arc.

At sunset these Arches often spectacular:

WOW!
We don’t mind them at all.


Origins of the “Chinook”

The word Chinook originally comes from the name of a Native American people of the Pacific Northwest—specifically a community in the Columbia River region of what is now Washington and Oregon. The term traces back to the Salishan language, where it referred to a particular village site.

Wishham young woman, circa 1910. Chinookan Indians: Tlakluit; Washington. Head-and-shoulders portrait of young Wishham Indian woman, facing right,...

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Winter 2024 … ?

At the beginning of December this happened …

Snow.

We weren’t surprised.
It’s Winter.
So I went out and shovelled the sidewalk.
Then …
This happened …

It’s called a Chinook Arch (around here).
A Chinook is a warm wind that comes across the Rockies
from the West Coast – and raises the temperature
to balmy conditions.
We’ve had about 12 Chinooks so far this year.
That’s not normal.
But they just keep coming.

A Chinook arch can span the Rockies all the way from
Northern Alberta to New Mexico, USA
Around here that can bring weather like this:

We know this won’t last.
But we’re appreciating it while we can.
???

Leo and the Chinook …

Leo and the Chinook

I see that Leo Decapprio is sticking with his story about our Alberta Chinook winds as being proof of ‘Global Warming’. Leo experienced the Chinook phenomenon while The Revenant was being filmed in Alberta last winter.

chinook arch
Sooo, in the interests of Science and public awareness, I will attempt to set the record straight:

Wikipedia says:
Chinook winds /ʃɪˈnʊk/, or simply chinooks, are foehn winds in the interior West of North America, where the Canadian Prairies and Great Plains meet various mountain ranges, although the original usage is in reference to wet, warm coastal winds in the Pacific Northwest.”

Chinook is claimed by popular folk-etymology to mean “ice-eater”, but it is really the name of the people in the region where the usage was first derived. The reference to a wind or weather system, simply “a Chinook”, originally meant a warming wind from the ocean into the interior regions of the Northwest of the USA (the Chinook people lived near the ocean, along the lower Columbia River). A strong Chinook can make snow one foot deep almost vanish in one day. The snow partly melts and partly evaporates in the dry wind. Chinook winds have been observed to raise winter temperature, often from below -20 °C (-4 °F) to as high as 10-20 °C (50-68 °F) for a few hours or days, then temperatures plummet to their base levels. The greatest recorded temperature change in 24 hours was caused by Chinook winds on January 15, 1972, in Loma, Montana; the temperature rose from -48 to 9 °C (-54 to 48 °F).”

chinook arch 2

Some of this information is not quite accurate. Chinooks can easily last a week and I’ve experienced (though rarely) them lasting as long as 2 weeks – or more. The temperature range and change can be great and sudden – spanning an over 80 degree F change in a few hours. They can also occur in any month or season – but are obviously most noticeable in Winter.

chinook arch 3
These images shows a Chinook Arch – a rather spectacular (especially at sunset) and welcome phenomenon – as the clouds are driven by the West winds over the Rocky Mountains and forms these ‘arches’ that can span hundreds of miles from mid Alberta down into the US.

Chinook Tall Tales:

CHINOOK STORIES http://plainshumanities.unl.edu/encyclopedia/doc/egp.fol.006

” … Among the frontier yarns that were spun was the story of the man who hitched his team of horses to a post one snowy evening only to awake the next morning to find his horses dangling from the church steeple. Another often told story describes a horse-drawn sleigh racing a chinook home: as the horses struggled through chest-deep snow, the front runners of the sleigh sloshed through mud while the back runners kicked up dust, Another variant of this story has the man driving the sleigh in front suffering frostbite while his children in back catch sunstroke. … ”

There you go Leo …

Now stop your nonsense!