Widespread
gale damage in the southeast 
3/12/02,
24/12/02 
Hot night
in the east, cold in the west |
Six-hourly surface analyses from 12UTC (10pm EST) 14 September to 00UTC (10am EST) 16 September. BoM |
 |
|
What a difference a day makes! Maximum temperature departures from normal for yesterday and today. Parts of SW SA that were 13° above average yesterday were 7 below today. BoM |
Prolonged gale force winds caused extensive damage in South Australia, NSW, Victoria and Tasmania yesterday and today. The animation above shows the cause. A low of 986hPa under WA on Saturday night moved due east across the Bight yesterday afternoon while deepening to 981hPa and massively tightening the pressure gradient to a 1035 high in the central Tasman Sea. The High continued to refuse to budge overnight as the low drove around it to the southeast, deepening to 969hPa at 10 this morning when due south of Tasmania. Pressure gradients of this magnitude are most unusual in the Australian region, and widespread, severe gales resulted. Full details of wind averages and gusts are in the wind extremes box below.
In South Australia persistent gale force winds yesterday, gusting as high as 117km/h, raised widespread duststorms and prompted 800 emergency services calls to deal with unroofed houses, flattened sheds and fences, and trees on roads and houses. The greatest damage occurred on the easterh half of the Eyre Peninsula, Yorke Peninsula and the northern Spencer Gulf areas, with Whyalla alone accounting for 183 of the emergency calls. Warooka and Maitland each generated about 40 calls. Several houses in the area lost verandahs or parts of their roofs, and dozens of farm sheds and buildings were badly damaged. Tree damage was widespread, several boats were damaged when they broke their moorings, and powerlines were brought down. The damage bill is put at around $1m. On the Yorke peninsula, wind gusted to 108km/h (averaging 82) at Edithburgh, while on the Eyre Peninsula, Port Lincoln reported 104km/h and Wudina, Cleve, Whyalla and Coulta all reported gusts in the mid 90s. The gales produced duststorms that lifted large areas of topsoil in the Riverland and Mallee areas, adding insult to injury for farmers praying for rain. Many crops that were marginal have been ruined by the combination of heat stress and high wind. The highest wind gusts recorded were 117km/h at Minlaton Airport on the Yorke Peninsula and at Mt Lofty summit and Sellicks Beach, both near Adelaide. At Minlaton, the wind exceeded gale force for nine and a half hours, an unusually long duration for this area.
In Victoria the SES responded to 600 calls to deal with unroofed houses and downed trees and power poles. Most were from metropolitan Melbourne where the wind gusted to 85km/h at Melbourne and Moorabin Airports, 87km/h at Frankston, and 106km/h at Dunns Hill near Mt Dandenong. Most of the strongest gusts were recorded around 5.30am during the period of maximum pressure gradient across the city. Winds actually eased as the axis of the pressure trough passed through late morning ahead of the main front about 4pm. Damage was less than expected because many vulnerable trees and structures were blown down in the gales two weeks ago. Widespread wind damage and blocked roads were also reported from the Ballarat area. More fires flared up during the night, with the CFA called to over 300 incidents, 100 of them grass and scrub fires. The serious fire at Mt Monarch west of Ballarat threatened homes, while significant fires were also burning at Apollo Bay and at Westburn near Warburton. All fires were under control by late afternoon. The highest wind gusts recorded were at Mt Gellibrand near Colac, 117km/h, and the summit of Mt Hotham 139km/h, though there was an unofficial report of a wind gust of 190km/h at Mt Buller. Heavy rain fell across central and northeastern Victoria during the afternoon, with Edi Upper, 35km SSE of Wangaratta, recording 50mm between 9am and 3pm, and Hunters Hill near Koetong in the northeast reporting 53mm between noon and 6pm.
Wind damage was also reported from the NSW Snowy Mountains ski resorts, with a lodge in each of the Kosciuszko Chalet, Perisher Valley and Thredbo areas unroofed. The anemometer on Crackenback Range above Thredbo recorded its highest-ever peak gust of 154km/h with a sustained windspeed of 121km/h at 10am. In Tasmania, the wind gusted to 98km/h in central Hobart, and a top gust of 135km/h (average 111) atop Mt Wellington. A brick wall of a house in the Hobart suburb of Berriedale collapsed in the wind while a tree came down on powerlines in the state's northeast disrupting power for 10 hours.
There were strongly contrasting overnight temperature differences across the country. A 400km-wide belt running 1,500km from southeastern NT to eastern Victoria recorded mimina between 6 and 13° above average, while most of southern WA was between 4 and 9 below. Pearce RAAF Base, 35km NNE of Perth, recorded its coldest September minimum in 42 years of computer record when the temperature dropped to 0.7.