The big dust cloud that has been causing visibility and air quality problems in parts of Australia is heading to New Zealand.
Dust clouds in Australia behind a cold front (marked in blue) over the Tasman Sea. Photo: MetService
MetService said it would be blown across the South Island and may affect parts of the central North Island on Friday.
A large dust storm swept parts of New South Wales and Canberra this week as a cold front pushed strong winds ahead of it across the south east of the country. The storm brought wind damage and power cuts in the Canberra area, and thick dust was moving into southern Queensland.
The west coast of the South Island is forecast to be affected by some of this dust from Thursday morning through until Thursday night, and western parts of the North Island on Thursday night and into Friday morning.
Duty forecaster Heath Gullery said it would most likely cause redness in the sky at dusk and dawn.
"It's most likely to be seen as an extra redness in the sky during sunrise and sunset. There may be an extra bit of haziness in the sky," he said.
He said it was a fairly rare event likely caused by dust and smoke from fires in Australia. Most of the dust will be in the upper atmosphere.
MetService forecasters were not sure about the density and amount of dust that would eventually reach New Zealand but expected the cold front to make landfall over Fiordland this morning.
MetService Meteorologist, Andy Best told Morning Report the dust cloud was being monitored and it had decreased in intensity as moved across the Tasman.
"It's being picked up in quite strong west and northwesterly winds."
"We have been monitoring it overnight, it has decreased in intensity as it's come across the Tasman" - Andy Best
The origins of the dust trace back to the Great Artesian Basin, far southwest of Queensland.
"The satellite imagery yesterday showed quite an extensive area of dust around 600km wide extending from Sydney right up to the Gold Coast, extending southeast across the Tasman, about 1000 km. So, it's a large area of dust," Best said.
The latest imagery showed some opalescent dust just offshore from Hokitika.
It will move from the West Coast of the South Island all the way to Farewell Spit up to early this evening.
"It may then come around in the northwesterly flow ahead of that front to place from Taranaki to Manawatu and even into Wellington late this evening and overnight."
People will see it as fine particulate matter on plant leaves and on their cars.