Australian
Weather NewsAustralian
Weather NewsTuesday 26 August 1997, 12.45 EST
Clear skies, very low humidity, light winds and a residual cold airmass over the area were the recipe for an exceptionally cold start to this morning across much of the northeastern quarter of the continent. Minimum temperatures were generally between 7 and 10 below the August average across the North and Central Western Plains and Slopes, Northern Tablelands and North Coast of NSW; and the Central and Northern Highlands and Coasts and all of southern Queensland.
Greatest departures from normal were in southeast Queensland as far west as the Maranoa. Recording minima 10 degrees below normal were Monto with -4 degrees, Lady Elliott Island 7, Amberley -3, Oakey -6 and Roma -4. On 9 below normal were Georgetown 4 and Richmond 1 on the Northern Tablelands, Cooktown 11 on the North Coast, and in the south Gympie -1, Brisbane Airport 1.2, Goondiwindi -2.5, Dalby -3, Miles -3.5, and Surat and Charleville -3. Coldest report from Queensland was -6 shared by Injune, Oakey and Applethorpe, whilst the coldest grass minimum temperatures reported from the limited network of stations so equipped were -9 at Stanthorpe and -8 shared by Tambo, Texas, Oakey and Mitchell.
In NSW, the greatest departures from normal were 9 below at Inverell -8 and Lismore -1.4, and 8 below at Tenterfield -6, Armidale City -7.0. Murrurundi -5, Dunedoo -4.7, Coonabarabran -6.4, and Dubbo City -3.6. Coldest places were Woolbrook with -9.5, and Glen Innes Airport -9. Glen Innes Agricultural Station's grass minimum thermometer was again given a workout, recording -13. Light snow was reported overnight from Taralga and Oberon, and in the Snowys.
Monday 25 August 1997, 12.15 EST
Following yesterday's cold outbreak, minimum temperatures this morning were well below normal in parts of SA, Victoria, Tasmania, NSW and southern Queensland despite continuing fresh to strong winds. In southern Queensland, Goondiwindi and Texas both reported -3.5, 10 and 8 degrees below the August average respectively. Roma's -3 was 9 below. Across the border in NSW, minima around 7 below normal were commonplace on the Northwest Slopes and Plains and Northern Tablelands, with Coonamble (-4) and Inverell (-8) being 9 below, and Armidale city (-6.9) 8 below. Glen Innes Agricultural Station recorded a grass minimum thermometer minimum of -12. Murray Valley minima were generally 4 to 7 below, with Loxton (SA, -2), Horsham (Vic, -2.5), Mangalore (Vic, -3) all 7 degrees below the August norm. Light snow was reported from Bombala (NSW), Strathbogie and Omeo (Vic) and NSW and Victorian alpine stations and the Central Plateau in Tasmania overnight. Snow depths in the Alps are probably reaching their seasonal maximum, with this morning's reports of level snow depth being 103cm at Falls Creek (Vic), 114 at Kosciuszko Chalet and 30 at Cabramurra (NSW).
Sunday 24 August 1997, 19.10 EST (updated Monday 25 August 1997, 12.10 EST)
Australians in the southeastern states rugged up today as a blast of wintery southern air brought snow, wind and cold weather to most of the region. Tasmania, Victoria and New South Wales are now covered by an intensely cold airmass which moved in behind a front which crossed the area yesterday and overnight. Strong to gale force west to southwesterly winds have developed between a deepening and complex low, which moved eastwards across Tasmania overnight, and a high in the Bight. Because the airstream is very dry behind the cloud band associated with the front, snowfalls have been relatively light, though were still heavy enough in western Victoria to close some roads.
In South Australia, where the cold air clipped the southeastern corner of the state yesterday, Cape Northumberland reported hail along with a 15.00 temperature of 6.7 degrees, 7 below the normal maximum temperature.
In Tasmania, cold conditions developed yesterday morning with hail and sleet reported to sea level during the day and snow falling as low as 200 metres above sea level last night. Marrawah, on the northwest coast, Maatsuyker Island off the south coast, Geeveston in the southeast and Queenstown in the west all reported sleet or hail during yesterday afternoon, and heavy snow fell on western parts of the Central Plateau. Maatsuyker's midday temperature yesterday was 4.5 degrees. Some very low minimum temperatures were reported this morning -- minus 1.6 at Swansea on the east coast was 6 below average (the minimum on the grass was minus 5), whilst Hobart Airport's minimum was minus 1.3, 6 below. Conditions have eased somewhat today, with the slowline rising to around 500 metres, but fresh to strong winds have continued with maximum temperatures 3 to 6 below average.
Victoria felt the effect of strengthening northwesterlies ahead of the change from early yesterday, with Wilsons Promintory reporting wind gusts to around 50 knots at most observations from 06.00 onwards. With the passage of the front during the afternoon, Warrnambool reported hail and Redesdale, northeast of Ballarat, recorded 17mm between 15.00 and 18.00. Wintery conditions prevailed overnight: Mt Buller reported a temperature of minus 7.3 with a 47 knot wind at 03.00; light snow was reported (or can be inferred from automatic weather station reports) from Ballarat, Hamilton, Colac, the Dandenongs, Hunters Hill west of Corryong, the Strathbogie Ranges, Eildon Fire Tower, Noojee and Omeo; hail was reported from coastal stations with thunder at Wonthaggi; and Wilsons Promintory recorded several wind gusts to 59 knots between midnight and 06.00 this morning. Minimum temperatures were generally 2 to 7 below average, with Mt Hotham recording minus 8.8. Today, maximum temperatures were generally between 8 and 12 degrees, or 3 to 6 below average. However, Mt Hotham's midday temperature was minus 6.2, Gelantipy in East Gippsland was 2.5 and Dunns Hill, on Mt Dandenong, was 2.4. Coastal stations continued to report strong to galeforce winds, with Point Hicks and Gabo Island averaging 40 knots at 15.00.
New South Wales only caught the top end of the rainband, but light snow or sleet was still reported overnight from Tumbarumba and Bathurst, and overnight and during today from Orange and Oberon as well as the Southern Tablelands down to 800 metres. In the prefrontal northwesterlies yesterday, the automatic weather station on Thredbo Crackenback reported a 10 minute average wind of 68 knots at 15.00. Unfortunately, the NSW Regional Office of the Bureau of Meteorology has had computer problems today, and many reports, particularly automatic weather station reports, have not been available. Maximum temperatures today in all except the northeastern corner have been 3 to 6 below normal, but Tumbarumba's top of 3 and Oberon's 1 were 9 below, and Bathurst City (6), Wilcannia (14), Broken Hill (11), Gulgong (9), Orange AP (3), Lithgow (5), Cooma (7), Cabramurra (-3) and Lake Cargelligo (11) were 7 below.
The cold outbreak has produced some very low upper air temperatures. Melbourne Airport's balloon ascent late last night reported a temperature of minus 35 degrees at 500hPa (about 18,000 feet). The August average is minus 24. This morning's ascent reported minus 14 at 10,000 feet and minus 30 at 18,000 feet. Hobart's ascent this morning reported minus 14.7 at 10,000 feet (normal is minus 8.1) and minus 33.7 at 18,000 feet (normal minus 25.5), whilst Wagga's respective figures were minus 14.7 (normal minus 6.5) and minus 26.5. Data from aircraft taking off from Sydney Airport have indicated a freezing level around 3,700 feet this afternoon, with temperatures down to minus 14 at 10,000 feet. Analyses of temperature at 850hPa (around 5,000 feet) at 09.00 this morning show temperatures of between minus 3 and minus 7 for most of NSW and Victoria.