BAMOS Vol 32 No.4 December 2019 | Page 25

BAMOS Dec 2019 Charts of the Past with Blair Trewin 3 October 1967 1967 was an exceptionally dry year in many parts of southeastern Australia. It was the driest year on record for Melbourne, Adelaide and the state of Victoria, with Tasmania (which had experienced destructive bushfires early in the year) having its third‑driest year. The most extreme dry conditions, relatively speaking, were in southwest Victoria and southeast South Australia, with Mount Gambier setting a low annual rainfall record by nearly 100 mm. One of the year's most unusual weather events was a cold outbreak that affected the southeast in early October. A deep low pressure system moved south of Tasmania on the 1st and 2nd, with a strong southwesterly airstream in the wake of an associated cold front, which crossed the southeast mainland on the 2nd. The front brought damaging winds to parts of the New South Wales coast, and a bushfire occurred in the Sydney suburb of Frenchs Forest; northwesterly winds also contributed to a dust storm in Birdsville and raised dust in parts of western New South Wales, and led to the further spread of fires that had been burning for some weeks north of Alice Springs. The wind turned rapidly easterly on the 3rd over southern New South Wales, as a ridge extended to the south, but cold air remained in place on, and east of, the ranges, with the easterly flow providing additional moisture. This set the scene for an unusual spring snow event in southern New South Wales and the ACT. Snow fell widely above 600 metres elevation, with settled snow in many Canberra suburbs. The cold conditions persisted through the day, resulting in some exceptionally low maximum temperatures. Braidwood's maximum was 1.7 °C, by far the town's coldest day on record for any month (their next coldest is 5.0 °C), whilst other notable low maxima included 3.6 °C at Cooma and 3.9 °C at Nimmitabel. After remaining below 5 °C all day, temperatures in Canberra warmed the next morning to reach 7.2 °C before 9am, still an October record low maximum by more than 1 °C. It was also a cold day on the coast, with October record low maximum temperatures at Moruya Heads (10.4 °C) and Point Perpendicular (11.1 °C), but the cold was relatively localised, with temperatures from northern New South Wales northwards remaining above average throughout. The cold also contrasted sharply with warm conditions in the lead‑up; Canberra's maximum of 7.2 °C on the 3rd had been preceded by 25.1 °C on the 2nd. Although this was not an exceptionally wet system, there were some moderate falls of rain on the coast once the flow turned easterly, including 36 mm at Pambula and 29 mm at Nelligen. These falls extended to eastern tableland areas with a fall of 26 mm (much of which would have fallen as snow) at a site near Braidwood. Earlier during the passage of the front, there were falls of 30–50 mm in western Tasmania, but in Victoria totals only locally reached 20 mm in the Alps and parts of East Gippsland. Temperatures further south were also less exceptional than they were in southern New South Wales, although it was still cold, with Melbourne only reaching 11.5 °C on the 2nd, and Hobart 10.1 °C. The most significant low temperatures of the 2nd were in South Australia; Adelaide's maximum of 11.7 °C was only 0.5 °C above its October record, whilst Mount Barker set an October record of 9.2 °C. On the other side of the country, an active late‑season front was approaching the Western Australian coast, with widespread rain in the southwest. The heaviest falls were in the Perth area, accompanied by widespread thunderstorms, which caused lightning damage in many suburbs. Perth's daily total of 50.0 mm was an October record at the time, although there have subsequently been heavier falls in 1995 and 1978. Synoptic chart 0900 AEST (2300 UTC), 3 October 1967. Note: analysis practices for fronts were different to the present day 25