Paper Reviewed
Rasuly, A.A., Cheung, K.K.W. and McBurney, B. 2015. Hail events across the Greater Metropolitan Severe Thunderstorm Warming Area. Natural Hazards and Earth System Sciences 15: 973-984.

Severe hailstorms in Australia are defined as storms producing hail with a diameter of 2 cm or more. According to Rasuly et al. (2015), each year severe hailstorms across the Greater Metropolitan Severe Thunderstorm Warning Area (GMSTWA) of New South Wales cause severe damage to urban infrastructure, property and crops "worth more than AUD 100 million." Such storms can also produce maximum hail sizes greater than 7 cm and can cause human injury and death. Given that "the future impacts from climate variability to the hailstorm frequency and magnitude in the [GMSTWA] region need further studies, especially under an unpredictable future climate change," Rasuly et al. set out to provide an analysis of historic trends to provide a baseline understanding of severe hailstorms in this region over the period 1989-2013. Data for their study were obtained from a severe storm archive at the Australian Bureau of Meteorology and the specific parameters analyzed included "hail frequency, hail days and hail magnitudes (sizes) in the local government areas."

In discussing their findings, Rasuly et al. report there was a total of 357 hail events (diameter from 2-11 cm) that occurred across the region in 169 hail days over the period of study. They also determined that hail events were "neither temporally nor spatially uniform," and there was tremendous variation in terms of "size, location, intensity and frequency of occurrence inside GMSTWA." However, they pointedly note that there has been "a significant decreasing trend in hail frequency and associated magnitude in the recent years."

Such observations do not bode well for climate alarmists, who continue to claim extreme weather events should be increasing due to anthropogenic global warming.