This report has been renamed and expanded and will be updated as more information becomes available
Visible concentrations of volcanic ash from the Chilean Mt Puyehue eruption are predicted to enter airspace over Adelaide early tomorrow morning and then track across SE Australia north of Melbourne and just south of Sydney and in the vicinity of Canberra, posing a risk to flights until sometime tomorrow night.
The head of the BoM Volcanic Ash Advisory Centre in Darwin, Dr Andrew Tupper, said laser sounding or LIDAR readings from a satellite showed that the layers of ash are concentrated right across the normal range of jet airliner cruising altitudes of between 8000-13,000 metres with a lower limit of around 6000 metres.
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At 2 pm eastern time Tiger Airways said it would provide operational updates on its services after 4 pm, and again after 10 pm. At 3 pm Qantas said all of its domestic and New Zealand flights were operating as scheduled in coming days. There has been no recent update on the Virgin Australia site.
Dr Tupper said that while Australia received only the fringes of the volcanic ash cloud last week, which mainly affected New Zealand, it would this time around track more directly across the Australian mainland.
He emphasised the dynamic variability of the cloud which was currently about 2000 kilometres south of Western Australia but said that a strong weather system was expected to drive the cloud NE, reaching Adelaide airspace between dawn and 10 am local time and then spreading into southern NSW.
The main concentration of ash in the cloud appeared to be about 1500 metres thick and at around 10,000 metres, however, the structure was complex, comprising layers of concentrated ash which were strongly visible to the naked eye in daylight.
Dr Tupper said the cloud concentrations due tomorrow were last week’s plumes making a second pass, and while they had become more diffuse in general, the difference this time was in their following a track that would pass directly over the SE part of the continent.
He said the airlines had been in continuous contact with the volcanic ash advisory centre and that the risk of a major incursion of the plumes into Australian airspace had become more apparent over the last 18 hours, or since Sunday evening.