chinook

Canadian Slang

(Pronounced "shinook" in some areas) a warm dry wind blowing down the eastern slopes of the Rockies across Alberta and the prairies. Chinooks can cause temperature to rise by 20°F to 40°F within as short a time as 15 minutes.

Winter storm system that causes warm weather

a warm, dry wind experienced along the eastern side of the Rocky Mountains in the United States and Canada. Most common in winter and spring, a chinook wind can result in a rise in temperature of 20 C° (36 F°) in a quarter of an hour. In Alaska, the word is pronounced with an affricate ch instead of the fricative sh sound as used in Canada, and means an extremely wet, warm, constant southwesterly, which actually is the same weather pattern as the drying wind that it becomes when it hits Alberta. The use of the word to mean a wind is from the Chinook Jargon, "i.e., the wind from the direction of the country of the Chinooks" (the lower Columbia River), as transmitted to the Prairies by the francophone employees of the North West Company, hence the Frenchified pronunciation east of the Rockies. A Chinook in BC is also one of the five main varieties of salmon, and can also mean the Chinook Jargon, although this older usage is now very rare (as is the Jargon itself).