Worst
dust storm in decades sweeps across four statesOther notes on significant weather for today not yet written
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| This satellite image above, from NASA's Land Rapid Response System, shows the enormous spread of today's dust storm. The image was taken about 11am EST as the dust storm arrived in Sydney, and has been corrected to show true colour. The dust extends 1,500km from east of the southeastern corner of Australia at the bottom right of the image to near Mt Isa in Queensland at the top left. The red dots mark active bushfires. The 10am EST weather map from the BoM below shows the location of the cold front and surface trough at about the same time. |
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A strong, gusty southwest wind change swept tens of millions of tonnes of dust across eastern states today, giving many areas one of their worst dust storms on record. Raised dust, which was widespread in South Australia yesterday, spread across northern Victoria and NSW overnight, arriving in SW Queensland and eastern NSW after dawn this morning. The dust storm was at its worst in western NSW and Queensland, with visibility reduced to 50m in places as fresh dust was whipped up from bone dry soil with reduced vegetation cover and mixed through the lower atmosphere by strong, gusty winds.
Professor Grant McTainsh, a wind erosion specialist at Griffith University Queensland, said "This is one of the biggest dust storms in the last 20 years, it's enormous. It could easily have tens of millions of tonnes of dust. It was 6km high at Charleville, southern Queensland. That's incredible. Usually, storms stop picking up dust as they move east. But this picked up dust all the way to the coast." Professor McTainsh said a million tonnes of dust was equivalent to 200,000 semi-trailer loads. "That's two million trailer loads of dust blown away. Most of it ended in the ocean."
The dust storm covered over 450,000 square kilometres of NSW and Queensland, obliterating the sky with an orange/red veil and turning the sun into a dull silvery yellow disc. Visibility at Lightning Ridge in NW NSW during the morning was unofficially reported as low as 50m, and was officially measured at 100m at Roma, Qld, during the afternoon. Visibilities of between 300 and 500m were common across inland NSW and Queensland during the height of the storm. The mayor of Murweh Shire, which includes Charleville Qld, said it was the worst dust storm in the area since 1965.
In Sydney, Julie Evans from the Sydney Bureau of Meteorology said the dust storm arrived around 11am, reducing visibility to a few kilometres and extending 2.5km up into the atmosphere. Previous dust storms in Sydney occurred in April 1994, September 1968, December 1957, and January 1942, when the most severe dust storm to hit the city reduced visibility at Sydney airport to 500 metres.