Air New Zealand, however, has continued to operate as normal.
The company's general manager of airline operation and safety, chief pilot Captain David Morgan said the airline expected to operate its normal schedule of flights to and from airports in this region including Invercargill, Queenstown, Dunedin, Timaru and Christchurch.
"With the ongoing presence of ash, Air New Zealand is working closely with the Civil Aviation Authority (CAA) and the MetService to identify safe flight paths below or around areas of ash," Mr Morgan said.
Since ash from the volcano first arrived in New Zealand airspace on June 12, Air New Zealand has operated more than 7,700 domestic, Tasman and Pacific Island flights carrying more 460,000 passengers.
Civil Aviation Authority meteorology manager Peter Lechner said ash plume stretches from south of Australia around to nearly South America.
"The tail of the plume south of Australia is low, and then it comes up south of New Zealand to a high altitude as it stretches out to South America," Mr Lechner said.
"What has happened is the southerly/southeasterly we've got at the moment bringing up all that cold air ... has brought a bit of that cloud out over the South Island and that will sit around for a day or so and then move off to the east.
Mr Lechner expected the ash to remain above the South Island tomorrow before drifting east.
"It will probably get as far north as roughly around the Kaikoura area. The North Island shouldn't see it," he said.
"It is still at 20,000ft so the airlines can operate safely underneath should they choose to do so."
* For information on Jetstar flights go to its click here.
* For information on Qantas flights go to its click here.
- NZ HERALD STAFF, NEWSTALK ZB