Canterbury Nor'wester

This unusual formation is part of a northwest cloud arch over Canterbury, New Zealand caused by a foehn wind.

Canterbury Nor'westers blow warm, strong, and dry in the lee of the Southern Alps. Through the  "roaring forties," (windy 40-50 latitudes), they form anticyclones. Over the Canterbury Plains of the South Island, these winds are hot and enervating. As they veer westward, temperatures fall with the arrival of frigid air from the South Pole.