Chinook wind
Chinook winds, or simply Chinooks, are two types of prevailing warm, generally
- Along the Pacific Northwest coast, where the name is pronounced /tʃɪˈnʊk/ ('chin'+'uk'),[2] the name refers to wet, warm winds off the ocean from the southwest; this is the original use of the term.[1] The coastal Chinook winds deliver tremendous amounts of moisture both as rain along the coast and snow in the coastal mountains, that sustain the characteristic temperate rainforests and climate of the Pacific Northwest.
- In North American western interior, the same name is used for föhn wind, interior Chinooks are not necessarily originally coastal Chinooks.
In the interior of North America, the
A strong
In the Pacific Northwest
"Chinook" is used for coastal Chinook winds in British Columbia, and is the original use of the term, being rooted in the lore of coastal natives and immigrants, and brought to Alberta by French-speaking fur-traders.[1][8] Such winds are extremely wet and warm and arrive off the western coast of North America from the southwest.
These same winds have more recently been called the
The air associated with a coastal Chinook is stable; this minimizes wind gusts and often keeps winds light in sheltered areas. In exposed areas, fresh gales are frequent during a Chinook, but strong gale- or storm-force winds are uncommon; most of the region's stormy winds come when a fast "westerly" jet stream lets air masses from temperate and subarctic latitudes clash.
When a coastal Chinook comes in when an Arctic air mass is holding steady over the coast, the tropical dampness brought in suddenly cools, penetrating the frozen air and coming down in volumes of
The effects on the
Pronunciation in the Pacific Northwest
The word "Chinook" remains in common use among local fishermen and people in communities along the British Columbia Coast, and coastal Washington and Oregon, and in particular, the term is used in the Puget Sound area of Washington. Coastal "Chinook" is not pronounced shin-uk (/ʃɪˈnʊk/) as it is in the interior, east of the Cascades, but is in the original coastal pronunciation chin-uk (/tʃɪˈnʊk/).[2]
In
First nations myth from British Columbia
Native legend of the
Chinooks in Alberta and eastern British Columbia
Interior Chinooks are most prevalent over southern
In Pincher Creek, the temperature rose by 25.5 °C (45.9 °F), from −23.2 to 2.2 °C (−9.8 to 36.0 °F), in one hour on 6 January 1966.[11] During the winter, driving can be treacherous, as the wind blows snow across roadways, sometimes causing roads to vanish and snowdrifts to pile up higher than a metre. Empty semitrailer trucks driving along Highway 3 and other routes in southern Alberta have been blown over by the high gusts of wind caused by interior Chinooks.
On 27 February 1992, Claresholm, Alberta, a town just south of Calgary, recorded a temperature of 24 °C (75 °F);[12] again, the next day 21 °C (70 °F) was recorded.[12]
Clashing with Arctic air mass
The interior Chinooks can seem to battle with Arctic
This clash of temperatures can remain stationary, or move back and forth, in the latter case causing such fluctuations as a warm morning, a bitterly cold afternoon, and a warm evening. A curtain of fog often accompanies the clash between warm to the west and cold to the east.
Chinook arch
Two common cloud patterns seen in the interior during this time are a chinook arch overhead, and a bank of clouds (also referred to as a cloud wall) obscuring the mountains to the west. The bank appears to be an approaching storm, but does not advance any further to the east.
One of its most striking features of the interior Chinook weather system is the Chinook arch, a
A similar phenomenon, the Nor'west arch, also a föhn cloud, is seen in southern New Zealand.
The stunning colors seen in the Chinook arch are quite common. Typically, the colours will change throughout the day, starting with yellow, orange, red, and pink shades in the morning as the sun comes up, grey shades at midday changing to pink / red colours, and then orange / yellow hues just before the sun sets.
-
Chinook arch over Calgary, 6 January 2003
-
The extreme colors of a Chinook arch
-
Chinook arch in Calgary, Alberta, 19 November 2005
-
Chinook arch over Calgary, March 2007
-
Chinook arch over Kelowna, BC, Canada, 2 October 2007
Cause of occurrence
The interior Chinook is a
Sometimes the interior Chinooks are caused by the same air flow as the coastal Chinooks: As moist winds from the Pacific (coastal Chinooks) are forced to rise over the mountains, the moisture in the air is condensed and falls out as precipitation, while the air cools at the moist adiabatic rate of 5 °C / 1000 m (3.5 °F / 1000 ft). The dried air then descends on the leeward side of the mountains, warming at the dry adiabatic rate of 10 °C / 1000 m (5.5 °F / 1000 ft).[13]
The turbulence of the high winds also can prevent the usual nocturnal
Quite often, when the
Interior Chinooks and gardening on Great Plains
The frequent midwinter thaws by interior Chinooks in Great Plains country are more of a bane than a blessing to gardeners. Plants can be visibly brought out of dormancy by persistent, warm interior Chinook winds, or have their hardiness reduced even if they appear to remain dormant. In either case, they become vulnerable to later cold waves.
Many plants which do well at
Health
Interior Chinook winds are said to sometimes cause a sharp increase in the number of migraine headaches suffered by the locals. At least one study conducted by the department of clinical neurosciences at the University of Calgary supports that belief.[14] They are popularly[clarification needed] believed[by whom?] to increase irritability and sleeplessness.
In mid-winter over major centres such as Calgary, interior Chinooks can often override cold air in the city,
Chinooks and föhn winds in the inland United States
In the North American western interior, winds that are generally called
On rare occasions, Chinook winds generated on the eastern slope of the Rocky Mountains have reached as far east as Wisconsin.[15]
Records
Loma, Montana has the world record for the most extreme temperature change in a 24-hour period. On January 15, 1972, the temperature increased from −54 °F to 49 °F (−48 °C to 9 °C), a 103 °F (58 °C) change in temperature.[16] [17]
Spearfish, South Dakota holds the world record for the fastest increase in temperature. On January 22, 1943, the temperature increased from −4 °F to 45 °F (−20 °C to 7 °C), a 49 °F (27 °C) change in temperature. This occurred in just 2 minutes.[18][19][20]
Spearfish, South Dakota also holds the world record for the fastest decrease in temperature, for the same day. On January 22, 1943, the temperature decreased from 54 °F to −4 °F (12 °C to −20 °C), a 58 °F (32 °C) change in temperature. This occurred in 27 minutes.[20]
Rapid City, South Dakota had the world record for the fastest decrease in temperature. On January 10, 1911, the temperature decreased from 60 °F to 13 °F (16 °C to −11 °C), a 47 °F (26.1 °C) change in temperature.[21]
Squamish winds, williwaws, and Chugach föhns
The resulting outflow wind is more or less the opposite of British Columbia / Pacific Northwest coastal Chinook. These are called a squamish in certain areas, rooted in the direction of such winds coming down out of Howe Sound, home to the Squamish people, and in Alaska are called a williwaw. They consist of cold airstreams from the continental air mass pouring out of the interior plateau via certain river valleys and canyons penetrating the Coast Mountains towards the coast.
A similar, local föhn wind regularly occurs in the Cook Inlet region in Alaska, as air moves over the Chugach Mountains between Prince William Sound and Portage Glacier. Anchorage residents often believe the warm winds which melt snow and leave their streets slushy and muddy are a midwinter gift from Hawaii, following a common mistake that the warm winds come from the same place as the similar winds near the coasts in southern British Columbia, Washington, and Oregon.
See also
- Catabatic wind
- Diablo wind
- Föhn wind
- Southeast Australian foehn
- Nor'west arch
- Pineapple express
- Santa Ana winds
- Sundowner winds
References
- ^ a b c d Costello, J.A. (1909). "The Indian and the South Wind". Siwash — Indian History of the Northwest. pp. 156–158. Archived from the original on 2007-10-28: "p. 156". Archived from the original on 2008-05-30, "p. 157". Archived from the original on 2008-05-30, "p. 158". Archived from the original on 2008-05-30.
- ^ a b c d e Tolmie, W.F. (1884). "Example of tshinook original pronunciation". Comparative vocabularies of the Indian tribes etc.
- ^ "Chinook wind". Encyclopædia Britannica. 2006.
- ^ "Snow Eater (The)". Telefilm Canada. 2013-10-17. Archived from the original on 2013-10-17. Retrieved 2019-05-14.
- ^ "Chinook – origin and meaning of the name "Chinook"". Online Etymology Dictionary (etymonline.com). Retrieved 2019-05-14.
- ISBN 978-1-305-11358-9.
- ^ "Sublimation – the Water Cycle, from USGS Water-Science School". water.usgs.gov.
- ^ "Word and Phrase Origins". The Facts on File Encyclopedia. New York, NY: Checkmark Books. 2000.
- ^ Edwards, Irene. Short Portage to Lillooet (various ed.). Lillooet, BC: self-published.
- ^ Bouchard, Randy; Kennedy, Dorothy (1977). Lillooet Stories. Victoria Sound Heritage. 6.1.
- ^ "Pincher Creek, Alberta". Environment and Natural Resources. Hourly Data Report. Government of Canada. 6 January 1966. Archived from the original on 2010-03-23. Retrieved 2021-09-30.
- ^ a b "Claresholm Waterworks Station". Environment Canada. Daily Data Report. Environment Canada. February 1992. Retrieved 28 April 2016.[permanent dead link]
- ^ a b Whiteman, C. David (2000). Mountain Meteorology: Fundamentals and applications. Oxford University Press.
- ^ "Chinooks and health". Migraines.org. Archived from the original on 27 November 2020. Retrieved 2 February 2008.
- US Department of Agriculture. Retrieved 6 February 2016.
- ISBN 978-0-7876-1034-0.
- ^ Horvitz, Andrew H.; et al. (13 September 2002). "On 13 September 2002, citing a unanimous recommendation from the National Climate Extremes Committee, the Director of NCDC accepted the Loma, Montana 24 hour temperature change of 103°F, making it the new official national record" (PDF) (Press release). American Meteorological Society.
- ^ "South Dakota Weather History and Trivia January". – National Oceanic and Atmospheric Administration's National Weather Service.
—Appendix I: – "Weather Extremes" Archived 2008-05-28 at the Wayback Machine. – National Oceanic and Atmospheric Administration. – (Adobe Acrobat *.PDF document). - ISBN 978-0-8032-8702-0.
- ^ a b US Department of Commerce, NOAA. "The Black Hills Remarkable Temperature Change of January 22, 1943". www.weather.gov. Retrieved 2024-03-03.
- ISBN 0-7876-1034-8.