A huge wall of dust swept across New South Wales and the ACT overnight, as a cold front picked up soil from drought-ravaged areas and dumped it on the coast.
As the cold front moved up from the south, satellite images showed masses of dust stretching from the South Coast to Canberra and Sydney.
In order for a dust storm to develop, the Bureau of Meteorology says the wind has to be strong enough to firstly dislodge the dust particles from the surface and then lift them up into the atmosphere.
Leading edge of the #duststorm is now reaching #Sydney, after pushing through #Canberra this afternoon & making its way up the #NSW coast. #Dust will build until the change hits the city late tonight. What's truly amazing is the pink is raised dust being pushed north west pic.twitter.com/zSb1e55j0w— Bureau of Meteorology, New South Wales (@BOM_NSW) February 12, 2019
“Once airborne, to lift the dust to high levels, the atmosphere must be unstable,” it said.
“This instability can often be created by intense surface heating or the passage of a trough or cold front across the region.”
On Tuesday, temperatures at Nowra fell from 34.3 degrees at 3pm to 17 degrees by midnight. The cool change brought winds of up to 70km/h, which caused dust to blanket much of the Shoalhaven.
On Wednesday morning, residents were greeted by pink skies and cars coated with orange dust.
The Office of Environment and Heritage issued an air quality warning for parts of the Illawarra forecast area, advising people with heart or lung disease should avoid outdoor exertion and stay inside as much as possible.
“If you have symptoms rest and use your reliever medicine. If symptoms persist, seek medical advice,” it said.
NSW Health recommends people with existing respiratory issues, as well as young children and the elderly, stay in air-conditioned premises. It has also reminded people on the road to reduce their speed and be repared to pull over if visibility deteriorates to less than 100m.
How the dust dust storm looked around NSW and the ACT
#Duststorm is continuing to impact #Canberra this afternoon. #Dust levels are still building in the city and may continue to for several hours as winds continue to push it from sth west #NSW. Air quality is being compromised. @Act_Health & @ACT_ESA advice https://t.co/n85DnySw7Jpic.twitter.com/vXpm45MhKE— Bureau of Meteorology Australian Capital Territory (@BOM_ACT) February 12, 2019