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Chinook winds , 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.〔(''The Indian and the South Wind'', p.156 ), (p.157 ), (p.158 ) in J.A. Costello's (''Indian History of the Northwest - Siwash'' ), 1909〕 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).〔Andrew H. Horvitz, et al. (On September 13, 2002 citing a unanimous recommendation from the National Climate Extremes Committee, The Director of NCDC accepted the Loma, Montana 24-hour temperature change of 103F degrees, making it the new official national record. )〕 ==In Canada== Chinooks are most prevalent over southern Alberta in Canada, especially in a belt from Pincher Creek and Crowsnest Pass through Lethbridge, which get 30 to 35 Chinook days per year on average. Chinooks become less frequent further south in the United States, and are not as common north of Red Deer, but they can and do occur annually as far north as High Level in northwestern Alberta and Fort St. John in northeastern British Columbia, and as far south as Albuquerque, New Mexico. In southwestern Alberta, Chinook winds can gust in excess of hurricane force []. On November 19, 1962, an especially powerful Chinook in Lethbridge gusted to . In Pincher Creek, the temperature rose by 41°C (74°F), from -19 to 22°C (-2 to 72°F), in one hour in 1962.〔[http://atlas.nrcan.gc.ca/site/english/learningresources/facts/superweather.html The Atlas of Canada - Weather]〕 Trains have been known to be derailed by Chinook winds there. 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 Chinooks. Calgary also gets many Chinooks – the Bow Valley in the Canadian Rockies west of the city acts as a natural wind tunnel, funneling the chinook winds. In February 1992, Claresholm, Alberta hit 24°C (75°F) – one of Canada's highest February temperatures. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Chinook wind」の詳細全文を読む スポンサード リンク
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