Air New Zealand flights from Auckland, Wellington and Christchurch were forced to turn around between 7am and 8am this morning, unable to land in Sydney because of freak red dust storms.
There is still no ETA on the flights being rescheduled.
Sydney Airport has not been closed. Some planes have been able to land, but many international flights have been diverted to Brisbane or Melbourne - or, like Air New Zealand’s, turned around. According to on-the-ground reports, the flow-on effect has now swamped Melbourne airport.
The freak dust storm is unprecedented in living memory, and covers much of New South Wales. Gale-force, 100km/h winds have carried dust from the outback into metropolitan areas according to the Australian Bureau of Meteorology, which mildly refers to the phenomenon as "raised dust". The sun hitting the blanket of dust has caused the Martian sky effect.
Windows are expected to drop in the afternoon, which will reduce the chaos factor but also leave the dust lingering over Sydney.
Health authorities have warned asthma sufferers and others with breathing difficulties to say in doors but otherwise most institutions are open as normal.
A selection of photos that Sydney-siders have posted online:
Sydney Morning Herald dust storm slideshow.
Health warning as dust blankets Sydney
Q&A: Are Australia's dust storm linked to climage change?