Southerly buster
They are caused by the interaction of a shallow cold front with the blocking mountain range that aligns the coast, and frictional contrasts over the mainland and the ocean that disconnect the flow.
[11] During the early days of the European settlement, Sydney's summer storms were accompanied by rolling red dust from the colony's brickworks.
[12] In 1869, following the connection of lighthouses and signal stations on the east coast of NSW to the electric telegraph network, a system was instituted to give shipping warning of approaching gales.
The success of the system was seen in 1870 when a newspaper reported, "About 9 o'clock, however, intelligence of a southerly burster was telegraphed from Eden, and by half-past 12 the expected 'brickfielder' blew over the city.
[34] The weather flags had been flown since 1912[35] from the flagstaffs on prominent buildings but as well, at Garden Island, a diamond shape would be hoisted for warnings during the day and a red light at night when a southerly buster was expected.
[37] This signal, indicating strong winds and rain, was not specific to 'southerly busters', but as the jingle advised:[38] Flashes short, prepare for gales, Gather the washing, furl the sails.
"Author Ruth Park makes a reference to the southerly buster in her novel Poor Man's Orange (1949):[12] After an unbearably hot day, the old men on the balconies were sniffing the air and saying, 'Here she comes!'
The women undid the fronts of their frocks and the little children lifted up their shirts and let it blow on their sweaty bottoms.On a hot day, a strong offsea gale develops from the south usually in the late afternoon and early evening, causing a rapid fall in temperature as it arrives, and sometimes a short rain and/or thunderstorm may accompany, especially if it is affiliated with a cold front coming from the south and a trough, with the strongest winds being at the leading edge of the buster.
The Buster progresses into a strongly stable boundary layer with warm, prefrontal landmass air that is between 100 and 200 metres deep transporting over the cooler waters.
This activity continues on the southern New South Wales coast, while areas leading the front are still experiencing hot northwesterly winds.
Wind gusts in excess of 40 knots (74 km/h) near ground level averages about three per year, which usually come about after very hot days and would tremendously ease within 30 to 60 minutes after the Buster's arrival, becoming rather light within a few hours.
A regular southerly buster is between 20 and 60 nautical miles wide, with the heavier winds concentrated on the seaward strip, with its depth being around 1000m, restricted by the height of the mountains to west.
Because busters seldom keep a staunch speed while advancing along the coast, its arrival has always been difficult to foretell, though meteorologists nowadays have the gain of satellite imagery and weather radar to foresee it, with wind warning issued by the Bureau of Meteorology.
[61] The strongest southerly buster on record at Sydney Airport occurred at 6:40 pm on 18 December 1948 with a maximum wind gust of 113 km/h (70 mph).
