and tornadoes – though the conditions that can produce thunderstorms are more random and “stochastic”, and difficult to characterise than, say, tropical cyclones. The research team has also investigated crop damage. While in the US tornadoes garner much attention, a tornado track might be only a kilometre or so wide and they are quite short-lived. A hail track is generally wider and hailstorms are more frequent. While farmers can’t do a lot with warnings except cover up equipment and themselves, Dr Soderholm says there is value in having information on frequency of hailstorms, because this helps to better inform insurance companies about risk. The WeatheX app and new radar will go some way to redressing the disproportionate investment in understanding bushfires and flooding compared with hailstorms, despite the headache numerous small hailstorms and giant hail events inflict on the insurance industry. “People don’t consider it life-threatening and people don’t see hail as a problem for communities, more a problem for insurance and industry,” Dr Soderholm says. “But it costs the country a lot of money.” 0
Big problem: hailstones above 6cm diameter can cause serious damage
Top five insured loss events normalised in 2017 dollars 1999
Sydney hailstorm
$5.6bn
1974
Cyclone Tracy
$5bn
1966
Cyclone Dinah
$4.7bn
1989
Newcastle earthquake
$4.2bn
1973
Brisbane flooding
$3.2bn
Top 10 hailstorms, normalised in 2017 dollars (excluding December 2018 event) 1999
Eastern Sydney hailstorm
NSW
$5,574,498,958
1985
Brisbane hail
QLD
$2,274,272,916
1990
Northern Sydney hailstorm
NSW
$1,681,692,745
2010
Melbourne storm
VIC
$1,625,980,165
1967
SEQ hailstorm
QLD
$1,595,957,781
2014
Brisbane hailstorm
QLD
$1,535,440,024
2010
Perth storm
WA
$1,344,798,983
2011
Melbourne Christmas Day hailstorm
VIC
$987,926,516
1986
Western Sydney hail event
NSW
$795,963,895
1976
Western Sydney hailstorm
NSW
$749,612,517
2016
November hailstorm
VIC, SA & NSW
$621,470,779
2007
Blacktown hailstorm
NSW
$586,787,347
Information supplied by the Insurance Council of Australia
Gathering data: hail expert Joshua Soderholm 44
insuranceNEWS
February/March 2019