Chinook Sunset - time lapse

This video is of a recent chinook that we've experienced here. The chinook that arrived on November 15th was quite strong. The chinook arch formed early in the morning and lasted the entire day. The chinook arch at the right of the frame is seen as the "gap" in the cloud deck. This is where the alto stratus clouds are formed in the lee of the mountains.

The associated chinook winds started to pick up around the time that the sun began to shine below the cloud deck. As a result, the cloud deck began to push further eastward right around sunset.

This fall, we've been seeing a lot of chinook activity. As a consequence, we've had temperatures that are well above the average.

The source of the this air flow is ultimately the result of the so-called "Pineapple Express", a flow of warm moist air that comes up from near the Hawaiian Islands and moves towards North America. The west coast of the continent tends to get the moisture from this flow; the prairie regions tend to get the dry, warm air that is left from this flow.

The chinook winds and associated clouds are formed by the adiabatic compression of Pacific air masses by the Rocky mountains as the air is forced over the mountains.

Visually, the chinooks can make much of day seem a bit grey and dull, but they more than make up for it with the warm temperatures that they bring. Everyone's mood seems to lift in Winter when a chinook arrives. The lighting effect that the sun has when it gets below the cloud deck often brings a striking sunset, and this particular chinook is no exception.

The view is looking South towards Antler Hill and Innisfail, Alberta.

The background music is Symphony no. 31 in D, KV 297-300a ''Paris'' III. Allegro by W.A. Mozart.

The video was filmed on November 15, 2009 at 100x real time.

Category:

Film & Animation

Tags:

• weather
• meteorology
• clouds
• chinook
• wind
• arch
• alto
• stratus
• Red
• Deer
• Penhold
• central
• Alberta
• Canada
• time
• lapse
• timelapse
• relaxation
• meditation

[cwaughtech]

Does Lethbridge get more chinooks than Calgary or is it fairly similar?

[canadianentropy]

@cwaughtech The chinook phenomenon occurs over a wide region all at once - even up to the Grande Prairie region. So Calgary and Lethbridge would get the same chinook event, but Lethbridge tends to get stronger winds and higher temperatures from the same chinook event. The winds are so strong towards the Crow's Nest Pass that in Pincher Creek there are mobile homes that are cabled down to prevent them from tipping over.

[cwaughtech]

@canadianentropy That is absolutely insane! Does the Chinook arch mean the Chinook is coming soon? Is there any way of knowing when it will come when you see the arch?

[canadianentropy]

@cwaughtech That's exactly right. You can see the arch firming in the southwest, and know warm air is coming. How long it takes depends partly on the strength of the system, but it usually shows arrives in a couple of hours in our area.

Always a welcome sight after a cold snap! :)

[cwaughtech]

@canadianentropy I know a bit because my uncle lives in Calgary. Do you live in the city of Lethbridge ?

[canadianentropy]

@cwaughtech I'm in the Red Deer area.

[arjay9]

This is a beautiful video, and starting around 2:45 it becomes truly magical!

I grew up in Alberta and I remember what a treat Chinooks were in the dead of winter! :o)

[canadianentropy]

It is basically the same thing - just without the umlaut. :) And I assume that the Americans call it a chinook also; chinook winds are what we have always called it. :)

[Vleertouwer]

So basically it's the same thing as a Foehn/Föhn wind? but then an American name for it, I assume...

[canadianentropy]

The chionook is a wind and associated cloud formation. They are formed when warm Pacific air passes over the Rocky mountains. The moisture is deposited in the mountains, but the air gets compressed due to the elevation gain. The result is a warming of the air due to adiabatic compression. When the winds emerge from the mountains and heads out over the foothills and the prairies it raises the temperature. A welcome relief for Canadian winters.

The chinook effect is also found in the US.