Australian Weather Calendar
February: Timely camera purchase captures Flavio's Christmas Day storm
Melbourne supervisor Flavio Bonicelli was on his way home to Carrum Downs after celebrating Christmas Day 2011 with his sister's family. He'd taken many photographs with his digital camera bought only the month before, after reluctantly retiring his film camera. 'I saw a nasty storm...by the time I got home it was unfolding. The cloud formations were quite spectacular,' he says. Flavio did photography courses in the 1980s and 1990s, enjoying refining darkroom skills over years. He largely ignored digital photography until he came to terms with the technology and its possibilities. He has a Fine Arts degree majoring in printmaking, and including drawing, and painting. He is exploring photography both artistically and commercially. The severe thunderstorms which developed in and around Melbourne during the afternoon and evening of Christmas Day 2011 caused flash flooding. Hail reached up to 6 cm in diameter, and there was a tornado at Fiskville. The Insurance Council of Australia reported more than 100,000 claims and estimated the damage at over $650 million.
Surface heating or convergence of winds often provides a trigger for rising moist air. Thunderstorms occur when this is initiated in a moist, unstable atmosphere. If the atmosphere is particularly unstable or the surrounding winds are favourable a thunderstorm can become severe, producing large hail, damaging wind gusts, heavy rainfall leading to flash flooding, or tornadoes. Severe thunderstorms can occur anywhere in Australia, but are most commonly reported on the east coast between Sydney and Brisbane.