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Chinook Wind (n.d.)  Retrieved April 10, 2019 from https://en.wikipedia.org/wiki/Chinook_wind

Mountain Nature.  (2005).  Chinooks – Warm West Winds.  Retrieved April 10, 2019 from http://www.mountainnature.com/climate/chinook.htm

Nkemdirim, L.C., (2015).  Chinook. Retrieved April 10, 2019 from https://www.thecanadianencyclopedia.ca/en/article/chinook

Oxford University Press.  (2019).  dry adiabatic lapse rate. Retrieved April 10, 2019 from  http://www.oxfordreference.com/view/10.1093/oi/authority.20110803095732430

The Weather Network.  (2017).  Wild temperature swing in Calgary: -9C to +9C, here's why.  Retrieved April 10, 2019 from  https://www.theweathernetwork.com/news/articles/calgary-temperatures-november-22-chinook-environment-canada/89731

University of British Columbia (2018).  Weather for Sailing, Flying & Snow Sports.  Retrieved April 10, 2019 from  https://www.eoas.ubc.ca/courses/atsc113/flying/met_concepts/02-met_concepts/02e-shear_at_aerodromes/downslope_windstorms.html

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Do Chinook Winds occur elsewhere in the world?

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Do Chinook Winds occur elsewhere in the world?

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Although the warm winds may be called a different name elsewhere in the world, winds similar to Chinook occur all over the world. In the European Alps, they are called "Föhn Winds". In central Asia, they are called "Afganet"; in the Andes of South America, these winds are called "Puelche"; and in southern California, they are known as the "Santa Ana Winds".

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Rapid and large temperature changes

Snow may melt or evaporate through sublimation

Loss of moisture due to significant drops in humidity

Rivers and Lakes may lose ice at 2.5 cm per hour

Strong, warm winds blow may carry sounds long distances

Effects on Agriculture

Loss of soil moisture

Snow offers insulation and protection for plants/animals. This is lost.

Summer Chinooks can damage small plants

Removal of snow provides winter grazing for livestock

If the temperature drops rapidly following a Chinook, a crust of ice may form on the snow which makes grazing difficult and may result in injuries to animal’s legs

It may result in lower costs for hay and winter feed

Abrupt temperature changes can cause pneumonia, septicemia and shipping fever in cattle

Wire fences can become electrified due to the strong positive electrical charge in the air. Cattle have been electrocuted in this way

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Meteorologist explains Chinook Winds in Calgary

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Meteorologist explains Chinook Winds in Calgary

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Wild temperature swing in Calgary: -9C to +9C, here's why

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Leeanna McLean
Digital Reporter

Wednesday, November 22, 2017, 3:03 PM - Temperatures varied across Calgary on Wednesday morning, with a whopping 18-degree difference recorded between two separate locations.

Around 6 a.m. local time, the temperature was at 9.1 oC in Springbank and minus 9.2 o C at Calgary International Airport.

While the contrast may seem odd to some, The Weather Network meteorologist Erin Wenckstern explains it's a natural occurrence in Alberta.
Visit our Complete Guide to Winter 2017/18 for details on the upcoming season, tips to survive it and much more.
"One of the many perks of living in the province is an atmospheric effect called chinook winds. It begins as a warm Pacific airmass rushes over the Rockies and descends on the lee side of mountains. As it sinks, the airmass dramatically warms and dries, flooding the Foothills with this Pacific air. However, warmer air is less dense than cold air, so it often needs to battle the cold air in place before you feel its presence," she said.

"If the wind is strong enough, then the warm air wins."

In December of 2015, A-list actor and producer Leonardo DiCaprio discussed witnessing the "terrifying" effects of climate change firsthand while in Alberta, filming his film The Revenant. Canadians heckled the star as he was not familiar with Chinooks.

It's not abnormal to see drastic temperature differences during a chinook event, even just across one city as the warm and cold air go head to head, Wenckstern added.

WATCH BELOW: Chinook winds in Alberta bring drastic temperature differences

"Back in 1962, Pincher Creek experienced a memorable chinook where temperatures rose over 40°C in just one hour -- from -19°C to +22°C."

A warm westerly flow is expected through the next several days across Alberta, with temperatures rising form west to east by Friday.

A system is forecast to form across the north Wednesday night, with the potential for some freezing rain ahead of the warm front from northern Alberta through Saskatchewan.

The seasonal average in Calgary for this time of year typically sits at 1 o C.

RELATED VIDEO: Leo vs. Chinook winds

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Wild temperature swing in Calgary: -9C to +9C, here's why

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Leeanna McLean Digital Reporter Wednesday, November 22, 2017, 3:03 PM - Temperatures varied across Calgary on Wednesday morning, with a whopping 18-degree difference recorded between two separate locations. Around 6 a.m. local time, the temperature was at 9.1 oC in Springbank and minus 9.2 o C at Calgary International Airport.

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The Chinook Winds occur in every season, but it is more distinctive and numerous in the winter, when the unseasonable warming it brings differentiates it from the normal cold winter weather.  The chinook can bring drastic changes in weather during the winter months resulting in snow thaws throughout the winter season.   The change can be dramatic. On January 11, 1983, the temperature in Calgary rose 30°C (from -17°C to 13°C) in 4 hours, and on February 7, 1964, the temperature rose 28°C, and the humidity dropped by 43 percent.

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How does the Chinook develop in Western Canada?

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How does the Chinook develop in Western Canada?

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Chinook winds develop in Western Canada when warm, moist air blows from the Pacific Ocean in the northwest region of North America toward the Rocky Mountain range. The air mass cools as it climbs the mountains, bringing rain or snow to the peaks. The air mass, now dry after releasing its moisture in the mountains, warms as it moves down the eastern side of the mountains. The air mass warms rapidly, eventually becoming warmer and drier than the original air mass coming from over the Pacific Ocean. When the winds suddenly change direction toward the west or southwest, the Chinook winds begin with rapidly increasing speeds.

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They can also happen even without the initial cold-under-warm layering of air. For this to occur, the air approaching the mountain range must be humid, such as air approaching from over the ocean or large lakes. As this humid air is forced upward over the mountain range, the air cools, causing water vapor in the humid air to condense into water droplets. Much of this liquid (or solid) water falls out on the windward side of the mountain range (see the sketch below).

The condensation process releases latent heat, causing the air to not cool as fast with increasing altitude as it normally would. However, when this air descends down the lee side of the mountain, it warms at the dry adiabatic lapse rate, causing it to be much warmer at location 6 in the diagram below than when it started at location 1. The net result is a warm, dry, downslope wind at location 5 on the sketch. When this happens in winter with snow on the ground, the warm dry air can evaporate the snow, nicknamed a "snow eater".

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A chinook occurs when the cold air layer is shallow enough that it is completely dammed behind the mountain range, then only the warmer-than-normal air at middle altitudes can flow over the mountains. The suction behind the mountain brings the warm air down toward the valley. As this air descends, it is compressed by the increasing air pressure as it gets to lower altitudes, causing the descending air to warm at about 10°C for each kilometer is descends. (This dry adiabatic lapse rate  is actually 9.8°C/km). The adiabatic lapse rate is the rate at which dry (i.e. unsaturated) air cools when rising adiabatically through the atmosphere as a result of the utilization of energy in expansion.

This phenomenon of a warm, dry, downslope wind is a Chinook (it's called a Foehn in Europe). These winds can be strong enough to blow the roofs off of houses, so they can be a flight hazard and a landing/takeoff hazard.

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Where does the Chinook Winds occur in Canada?

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Where does the Chinook Winds occur in Canada?

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The area shown in red in the map below has the most intense Chinook Winds in Canada which is the City of Lethbridge, Alberta and surrounding areas.  The area in orange which includes the City of Calgary and Medicine Hat are significantly affected. The area in yellow is affected, but to a lesser extent.

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Chinook winds are warm, dry, gusty, westerly wind that blows down the Rocky Mountains into the mountains' eastern slopes and the western prairies.