A strong northwest foehn wind descending the New Zealand Alps onto the Canterbury Plains of South Island, New Zealand. The nor'wester (as it is called locally) is responsible for strong, warm, gusty winds that can damage crops, cause uprooting of trees in forests, damage buildings and other structures, and cause soil loss. Its drying action increases the need for irrigation on the Canterbury Plains. It can occur throughout the year but has highest frequency in spring. It generally occurs immediately prior to the passage of a cold front over the South Island. It is responsible for the highest recorded air temperature in New Zealand (42. 4°C at Rangiora on the Canterbury Plains, 7 February 1973).