The apocalyptic red skies in Western Australia have generated considerable international media attention. Crimson dust whipped up by the strong outer winds of Severe Tropical Cyclone Narelle created this unusual phenomenon.

Spectacular weather events like this are not common in northwest Australia. They occur under very specific environmental conditions. Most of the tropical cyclones hitting this arid region don’t cause red skies. Mega dust storms which do change the colour of the sky often take place during prolonged droughts. Perhaps the most memorable storm traversed over Melbourne on 8 February 1983, turning the sky red-brown and later pitch black.

So what caused Cyclone Narelle’s dust storm and why was the sky so vividly red? Four factors came together to create these conditions: a very dry and exposed landscape with red soils, a lack of preceding rain, very strong winds ahead of the rain bands from the cyclone, and a particular wind direction.

Why was the dust storm so spectacular?

Australia’s northwest is one of just a few places in the world where tropical cyclones affect an otherwise arid desert climate. Other locations include the Arabian Peninsula and semi-arid parts of India and Pakistan. These........

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