Volcanic ash set for NZ return

Activity at Chile's Puyehue-Cordon Caulle volcano is starting to slow, but there is still more ash from the massive eruption coming to affect travel across Australasia. Photo / supplied/NASA

The ash cloud from Chile's Puyehue-Cordon Caulle volcano is set to return to New Zealand tomorrow as flights in Australia have again been affected.

Thousands of travellers in Australia will have their plans disrupted today with airlines cancelling flights to and from Adelaide because of the return of the volcanic ash cloud which is now making its second lap around the globe.

Qantas has cancelled all remaining Adelaide and Port Lincoln flights today, and all Canberra flights will be cancelled from 2pm NZT. Domestic Sydney flights will be cancelled from 5pm NZT.

There is also a possibility Melbourne flights will also be affected later today.

So far Qantas has cancelled 73 domestic flights and six trans-Tasman flights today.

At this stage Qantas's discount airline Jetstar has only cancelled flights to and from Adelaide, cancelling 18 flights so far today.

Virgin has suspended all flights to Adelaide and Mildura, while Tiger has cancelled all of its Australian fleet.

Air New Zealand is continuing to fly to all domestic and international services.

New Zealand Civil Aviation's manager of meteorology Peter Lechner said the ash cloud is south of Adelaide at the moment and is expected to move over Sydney by midnight.

He said it is expected to move over New Zealand sometime tomorrow.

"The ash cloud's base is 20,000 feet so fortunately that still allows considerable scope for aircraft operation," he said.

Mr Lechner said it is up to airlines though to decide for themselves whether they want to fly under the ash cloud.

The head of the Australian Bureau of Meteorology's Volcanic Ash Advisory Centre in Darwin, Andrew Tupper, said the initial explosive eruption cloud that went mostly over New Zealand last week is now two weeks old and ash at lower levels is dissipating.

But it is heading for southeastern Australia and the southern NSW coast today at cruising altitudes between 8km and 13km.

"It's not like we have got masses of ash coming over to blanket the continent at lower levels. It is just a high level cloud that happens to be at an inconvenient level for flying," Dr Tupper told reporters yesterday.

"It will obviously cause disruption, it will obviously prevent aircraft flying at the altitude of the cloud ... how they cope with that is their decision."

Virgin Australia group executive of operations Sean Donohue said the latest weather advice necessitates the suspension of flights to Adelaide and Mildura until further notice because the ash plume would be below 20,000 feet.

"The forecast suggests the ash plume will be below 20,000 feet over Adelaide and Mildura tomorrow. With this in mind we are suspending these services tomorrow," Mr Donohue said.

Airservices Australia said flights in and out of Melbourne may be affected from tomorrow as the cloud moved eastwards.

"There is a possibility that the ash plume could affect other parts of Australia, including Sydney and Canberra, from mid to late this week," Airservices said in a statement.

Flights in Australia and New Zealand returned to normal on Friday after six days of havoc caused by the ash cloud.

Chile's Puyehue-Cordon Caulle volcano began erupting on June 4, shooting a plume of ash into the air which made its way across the Atlantic and Indian oceans before reaching Australian and New Zealand airspace.

- Newstalk ZB, AAP