Brace yourself for ‘giant hail’ as storms increase along east coast

Hailstorms will become more frequent in Brisbane, Sydney and Canberra, and the size of the stones that the storms create will grow in Canberra, Sydney, Melbourne and Perth as the climate warms over coming years, new modelling shows.

With every degree the atmosphere warms, it can hold 7 per cent more moisture, creating more turbulent conditions and increasing the likelihood of damaging hailstorms, said Dr Tim Raupach, author of a paper on projected hail damage in major Australian cities.

His modelling compared the historical incidence of hailstorms over the cities, with conditions expected in a scenario where the climate warms by 2.4 degrees by 2080.

The result was that while there may be more hailstorms in Brisbane, the chances of “giant hail” being produced became far higher in Sydney, Canberra, Melbourne and Perth.

“In the historical scenario, Melbourne would be expected to see a 100-millimetre hailstone – 10 centimetres – every 20 years, but in the future scenario, it would be expected to see one every three years,” said Raupach, whose paper was published in the journal Geophysical Research Letters.

In Sydney and Canberra, as the atmosphere warmed, the chances of giant hail hitting the cities increased from every three years to every two years.

For Perth, the chances of a hail producing day creating giant hail are predicted to increase from around 14 per cent to around 21 per cent. In Kalgoorlie, the study projects that 10 centimetres of hail could fall every six years rather than every 18 in current conditions.

Raupach, a researcher in atmospheric science at the UNSW Climate Change Research Centre, said the purpose of the study was to compare the two atmospheric eras to explore the potential impact of climate on hail.