UPDATE Friday 5pm

Jetstar has announced all New Zealand flights (domestic, transtasman and international) for tomorrow (Saturday) have been cancelled.

Air New Zealand services continue as scheduled.

The Civil Aviation Authority (CAA) said the ash cloud has dropped to 18,000ft and is likely to continue to disrupt flights in New Zealand over the weekend.

CAA meterological manager Peter Lechner said normal flying heights range between 20,000-30,000ft.

UPDATE FRIDAY 3pm: Weather conditions have caused the troublesome Chilean ash cloud to drop to 18,000ft.

The Civil Aviation Authority (CAA) said this is likely to continue disruptions in New Zealand throughout the weekend.

Peter Lechner, CAA spokespeson, said ability to fly depends on the height of the ash cloud. He said airlines determine their safe flying levels but must meet CAA guidelines to adjust flight paths.

Previous reports located the cloud hovering at around 20,000-24,000ft.  

Jetstar, who has cancelled all flights for the rest of today, said it will not make an announcement on New Zealand flights until tomorrow.

The airline's website said it will proactively contact those travellers with cancelled flights.

Air New Zealand continues to operate its standard schedule.

UPDATE Friday 7am: Air New Zealand domestic and transtasman flights are running to schedule.

JetStar has cancelled domestic flights this morning.

Qantas, Virgin, Blue and JetStar have cancelled transtasman flights.

UPDATE Thursday 5pm: Jetstar and Qantas have yet to announce when they will resume New Zealand domestic and transtasman flights.

The airlines will resume flights in and out of Tasmania this afternoon at 5pm local time but they have made no further update on when New Zealand flights would resume.

Jetstar said this morning domestic and transtasman flights were cancelled today, while Qantas transtasman flights were cancelled until midday tomorrow.

Air New Zealand is continuing to fly despite the volcanic ash cloud. 

UPDATE: Thursday 9:35am: 

Qantas and Jetstar have cancelled transtasman and domestic flights today, according to the website of each airline.

UPDATE: Thursday 8:45am:

Airline passengers face another day of chaos as Qantas and Jetstar flights remain grounded this morning.

Both airlines have cancelled all transtasman and domestic flights scheduled before 10am.

Updates are due from both airlines this morning as to plans to resume transtasman flights at midday.

All Air New Zealand domestic and international flights are running to schedule, as the airline has chosen the more expensive option of flying below the ash cloud – hovering at 20,000 feet above Tasmania and New Zealand.

Disruption to domestic and transtasman flights could last for a few days at least, as Mt Puyehue Cordon Caulle continues to erupt.

UPDATE: Thursday 6am: Qantas has cancelled all transtasman flights scheduled before 10am.

JetStar has cancelled all transtasman and NZ domestic service scheduled before 10am.

All Air New Zealand domestic and international flights are listed as running to schedule.

UPDATE: Wednesday 4:30pm: While domestic flights are set to resume in Australia, the troublesome ash cloud causing disruptions around the globe is moving more slowly than expected over New Zealand.

Peter Lechner from the Civil Aviation Authority said the cloud will cover the country this evening and will hover at around 20,000 feet.

Qantas and its subsidiary Jetstar cancelled all New Zealand flights for the rest of the day and said it will update travellers this evening.

Air New Zealand says it constantly reviewing its services but has not made any changes to its schedule.

Lechner said the ash could take two to three days to pass and may do a third lap of the world.

Qantas has reportedly lost $21 million since Monday due to disruptions.

UPDATE WEDNESDAY 11:50am: Jetstar have just tweeted all New Zealand flights (international and domestic) have been cancelled for today.

UPDATE WEDNESDAY 7am: Flights over New Zealand are again being disrupted by volcanic ash from Chile's Cordon Caulle, with Jetstar and Qantas cancelling flights in and out of the country today.

Qantas last night announced all flights in and out of New Zealand from 7am today would be cancelled until further notice, with passengers advised to check the airline's website for further updates.

Jetstar said it had cancelled all flights to and from New Zealand until 12pm today. It would be issuing an update on afternoon flights, a statement said.

Qantas and Jetstar also cancelled flights from some Australian cities after earlier cancelling flights in and out of Adelaide, Newcastle and Sydney yesterday.

Ash clould will hit mainland NZ around midday
New Zealand Civil Aviation's manager of meteorology Peter Lechner told NZPA last night the ash cloud was moving across from South Australia, and was expected to head over New South Wales then across to New Zealand.

"It will be across Sydney later this evening (June 21) then will head out into the Tasman overnight. We expect it over the North Island from Whangarei to Levin by late tomorrow morning," he said.

"It's going to be at a height over 24,000ft, which allows plenty of scope for airline operations underneath."

Mr Lechner said it was up to individual airlines whether or not they continued flights as normal.

"As far as we can see, it's looking OK...we'll just have to see what happens overnight (last night)."

Air New Zealand said it was currently operating as normal at all domestic and international ports and would continue to monitor the situation.

Jetstar and Qantas last week cancelled services in Australia and New Zealand while the ash cloud circled the Southern hemisphere as Air New Zealand continued near normal operations by flying at a lower altitude.

TUESDAY 3pm: The return of the Chilean ash cloud - now doing its second circuit around the globe - has caused further travel disruption, leading Qantas and Jetstar to cancel several transtasman flights.

Jetstar cancelled four transtasman flights to and from Sydney, while Qantas cancelled all Sydney flights to and from New Zealand after 5pm today. 

A number of other airlines including Pacific Blue, Aerolineas Argentinas, and LAN Chile cancelled Australian services.

Ash from the Puyehue-Cordon Caulle volcano, which began erupting on June 4, was moving over Australia today and was expected to reach New Zealand some time tomorrow. 

Air New Zealand said today it was operating its standard schedule to all domestic and international ports.

It said it would provide an update should the situation change.