What is a Chinook in geography?

Chinook winds or simply Chinooks, are 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 Blackfoot people term this wind 'Snow Eater'.

A strong "Chinook wind" can make snow one foot (30 cm) deep almost vanish in one day. The snow partly melts and partly sublimates 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 15 January 1972, in Loma, Montana; the temperature rose from −48 to 9 °C (−54 to 49 °F).