Overview

• Modeling shows hailstorm occurrences could increase by about 29 percent in Canberra and Sydney and by 15 percent in Brisbane under a 2.4 °C warmer scenario.
• Projected maximum hailstone diameters grow by roughly 7.8 mm in Melbourne and 3.9 mm in Sydney and Canberra, making 10 cm stones in Melbourne a once-every-three-years event.
• Return periods for “giant hail” shrink from 20 years to three years in Melbourne and from three years to two years in Sydney and Canberra.
• Simulations indicate elevated hail risk extends to Perth while Adelaide is expected to see little change in storm patterns.
• Insurance industry leaders and researchers are calling for stronger building standards, improved forecasting and deep cuts in greenhouse gas emissions to limit future losses.