Australian east coast low

Generally, the low occurs when there exists a temperature contrast between the warmer Tasman Sea and cooler continental landmass (including the cold air in the upper atmosphere), a setup similar to lake-effect rain. The interaction of such airs create heavy moisture and heightened wind speed. • A shallow warm core or warm separation at low levels and a cold core in the upper troposphere ==Characterisation==

Explosive cyclogenesis is seen on average just once per year, but these storms cause significant wind and flood damage when they occur. Cold core cyclones are more predominant in the southern parts of the ECL region during the cool season, while hybrid cyclones are more regular closer to the tropics, particularly in the warm season. (Himawari 8) ECLs are the cause of more than 25% of yearly rainfall and more than 60% of days with mass coastal flooding or significant dam influxes. Regions East coast lows usually occur along the subtropical east coast of Australia from Gladstone in Queensland to the Victoria/New South Wales border in the South Coast (near eastern Gippsland), and often affect large populated cities such as Sydney and Brisbane, between which over one-third of the Australian population resides. More powerful systems may percolate inland into the Central Tablelands, New England, the Central West, South Western Slopes, the Monaro and, albeit rarely, the Orana and the Riverina regions in NSW; also the Australian Capital Territory, the Hume region in Victoria; as well as Darling Downs and the Brigalow Belt in Queensland, although the rainfall in these interior areas will often be insignificant. More recently, it was observed that around 22 east coast lows were recorded annually – around 2 to 3 causing daily rainfall above and 7–8 causing daily rain above . The incidence of these types of storms can be seen to fluctuate quite widely from one year to the next, with none in some years and the highest incidence being twelve in 1978/79. Another feature of east coast low development is the tendency for clustering of events when conditions remain favourable. For example, near Brisbane, almost one third of events occur within 20 days of a preceding event. Areas south of the low can experience heavy rain, while those at the north of the rotating low would experience sunny skies. The movement of the low pressure system is generally difficult to predict for weather forecasters. Correlations of east coast cyclones with the interannual differences of the Southern Oscillation Index (SOI) indicate a strong preference for these storms to form just after a large swing from negative to positive Southern Oscillation index values and especially between swings from negative SOI the year before and positive SOI the year after. This suggests a preference for formation of east coast cyclones between extreme events of the Southern Oscillation Index. A positive SAM is linked with a higher frequency of deep cyclones in August–October and of shallow upper cyclones in December–February. ==Examples==

• 30 June–3 July 2025. A strong East Coast Low caused severe flooding in parts of Eastern NSW, including Sydney • 2022 east coast lows :*2–7 July 2022. Severe flooding in parts of Western Sydney and the Hunter Region, in addition to 1 death and thousands of evacuations. (See 2022 New South Wales floods) :*7–8 March 2022. 22 deaths. (See 2022 eastern Australia floods) • 9–13 June 2021. 2 deaths. Widespread flash flooding across Gippsland in Victoria. 160,000 properties blacked out. Traralgon in the Latrobe Valley was one of the hardest-hit towns with 200 homes evacuated. The rainfall event was actually caused by a cut-off low that "had similar characteristics to an East Coast low". • 26–28 July 2020. • 5–6 June 2016 An east coast low combined with a King tide brought severe coastal damage, notably to Collaroy and Coogee, New South Wales along with flooding along the east coast and later severe flooding to Tasmania. • 2015 Australian east coast lows :*23–25 August, An unusual low formed late in the season bringing some flooding along the coast. of rainfall was recorded at Nowra in 48 hours. :*28 April–1 May – On 28 April the Bureau of Meteorology reported that an east coast low was forming off the coast of Fraser Island. Record breaking rainfall and strong winds were recorded in southeast Queensland and northern New South Wales causing 5 fatalities in the Caboolture area. :* 20–23 April At least 4 people died in an event that was described as the worst since 2007. Severe flooding affected the areas of and , inundating homes and isolating entire communities. Power and water access was restricted for tens of thousands of homes across the wider Hunter Region. • 14 October 2014, New South Wales saw wind gusts up to . A Bureau of Meteorology spokesman described the rainfall observed at Marrickville, Canterbury, and Sydney Airport as "probably what you'd expect to see in one location about once every 20 years", with rainfall totals in at falling in three hours described as a one in 100 years recurrence. Sydney Airport saw disruption to flights as the airport closed for a time due to high winds. In Port Botany the strong winds caused the Hapag-Lloyd cargo ship Kiel Express to break free. Waves off Sydney over were reported. 30,000 homes in the region were left without power. • June 2013 • 21 May 2009, an east coast low caused massive coastal erosion and major flooding of the Clarence River. June 2007 • June 2007 June 2007 Hunter Region and Central Coast storms the grounding of the bulk coal-carrying ship , ten deaths and insurance claims of around A$1.4 billion making it one of the most costly natural disasters in Australia's history. • 23 March 2005 • 2 October 2004, off Sydney • 27–28 July 2001 • 17–23 July 1984, A$53m insurance costs. • 26 May 1974, storm saw the shipwreck of the . • 6 July 1973, the cargo ship Cherry Venture ran aground on Teewah Beach in South East Queensland during the storm. • June 1967, a series of east coast cyclones had a major impact on the northern New South Wales and southern Queensland coasts. • June 1950, a series of east coast cyclones develop off the New South Wales coast during which Sydney registered its highest monthly rainfall on record, . • 20 August 1857, the Dunbar sunk near Sydney, with only one survivor. ==See also==