Canterbury Northwester
As Canterbury North Wester ( Māori parera , in everyday usage often Nor'Wester or Nor'west arch of English arch = "Bogen"), a special weather situation is on the east coast of New Zealand's South Island called. It is characterized by a wide strip of clouds in the otherwise cloudless sky, which is accompanied by strong wind currents coming from the northwest.
The Northwester is a typical foehn wind . Warm and humid air from the Tasman Sea meets the mountain range of the New Zealand Alps from the northwest . The wind moves in front of the mountains to higher altitudes, where it cools down very quickly. Shortly before the mountain range, in the West Coast region , the wind currents lose a large part of their humidity in the form of high rainfall, which leads to the formation of the temperate rainforests there . The remaining water molecules of the then relatively dry Nor'wester can be seen during and after the crossing of the Southern Alps as impressive clouds, which can be seen especially in the Canterbury region as a band at the top of every air surge. This wave form comes about when the moisture - similar to a standing wave - condenses at the tip of the arches and thus becomes visible as a cloud and condenses again at the lowest point of the wave arch.
The cloud formations and the foehn wind extend over the whole of southern Canterbury starting at Amberley in the north to Central Otago deep in the Otago region in the south and is particularly noticeable in the flat Canterbury Plains . The largest settlement within the Nor'wester's sphere of influence is Christchurch , the largest city on the South Island.
The dry, warm foehn wind from the north-westerly direction not only causes intermittent droughts in the normally very fertile region, but has also been shown to have an impact on the human psyche : During the blowing gusts, suicide rates rise and cause headaches , depression and increased domestic violence. Particularly strong gusts of wind at gale force can cause considerable damage to buildings. In late winter, the Nor'wester ensures mild temperatures and heralds the coming spring.
See also: winches and wind systems