NSW, VIC, TAS: Rain, storms and flooding affect three states
The deep low near TAS and its attendant cold front visible on the surface chart above continued to agitate weather across the southeast today. Flash flooding was reported in southern NSW while heavy rain raised river levels in NE VIC and northern and central TAS. While storms in the southeast moved out into the Tasman this morning, they redeveloped along the troughline through QLD and the NT this afternoon, while both storms and areas of heavy rain developed across eastern TAS, VIC and NSW during the afternoon as an upper cold pool moved through.
Storms caused flash flooding on both sides of the NSW/VIC border near Albury overnight. Flash flooding between 7 and 10pm last night swept four cars from the Olympic Highway along a 10km section between 5 and 15km south of Culcairn, 45km north of Albury. Three of the cars aquaplaned, but a fourth was washed from the highway by about half a metre of fast-flowing water. The highway was closed from 8.24pm to 8.54 this morning. Culcairn recorded 63.0mm in the 24 hours to 9am. Across the border in VIC, flash flooding at Eskdale and Sandy Creek (50 and 25km SE of Wodonga) required SES crews to divert water flowing off paddocks that was threatening to inundate farmhouses. Farther east, Towong Shire in the upper Murray Valley estimated bridge and culvert damage from the weekend storms would top $300,000.
As the rainfall map shows, many areas on and west of the Central and Southern Tablelands recorded 15 to 50mm, often with much of the total falling in a few hours overnight. Parkes Airport recorded 40mm in 6 hours to 3am.
Continued heavy falls of rain on and around the Alps caused main river flooding in NE VIC and the Mitchell River basin in East Gippsland, with snowmelt enhancing the rainfall in the warm airmass ahead of the front. Perisher Valley's 24-hour total of 90.0mm was just 1mm shy of its 22-year September record. Rain finally turned to snow on both the VIC and NSW Alps just before dawn this morning, about the same time as the heavy precipitation ceased and river levels in upper reaches began to fall.
- The upper Mitta Mitta River at Hinnomunjie Bridge near Omeo peaked at 3.07m at 4pm yesterday, just above major flood level; the river fell slowly back to minor levels today, and Dartmouth Dam absorbed the flood flow resulting in only local flooding downstream.
- Outflows from Khancoban Storage ran well above minor flood level (113 cubic metres/second) all day, reaching 255 cubic metres/second mid morning) resulting in moderate flooding in Swampy Plains River and the upper Murray River downstream. The Murray at Biggara peaked at 2.43m (0.17 below moderate) about 1pm and at Bringenbrong peaked around 3.42 (0.02 above moderate) around midday.
- The King River peaked at 3.97m at 3am, just above moderate flood stage, while the Ovens at Wangaratta peaked at 11.98m at 9pm Monday, just above minor level. Levels elsewhere in the King, Ovens and Buffalo Rivers were just below minor.
- The Kiewa River at Mongans Bridge peaked at 3.1m at 5am, and at Bandiana at 2.79m early in the morning, both above minor flood levels.
- Streams flowing south from the VIC Alps into the Mitchell basin, particularly the Dargo and Wonnangatta, reached near-minor levels during the day.
In TAS, the main low pressure centre hugged the South Coast overnight then moved slowly ESE, but the development of a second centre just north of Launceston during the afternoon, as cold upper air moved through, gave a period of heavy rain in the state's northeast. Launceston recorded 42mm between 3 and 9pm. The combined lows moved SE during today, lashing the east and SE coasts with moist gale force winds that gave some record September falls and set streams rising (see tomorrow's Daily Weather Summary). Top wind gusts were 120km/h at Maatsuyker Island, 115 at Cape Grim and 107 atop Mt Wellington. Gales were also experienced across Bass Strait.
More details of heavy rain are given in downpours and the rainfall columns of the Noteworthy weather observations.
QLD, NT: Storms bring isolated heavy falls: The cold front sweeping southeastern states produced a northward extension in a trough passing through central QLD. Scattered thunderstorms developed in the warm, moist air near this trough, one giving Longreach Airport 21mm between midnight and 3am for a 24-hour total of 28.0mm, its heaviest September fall in 50 years. There were some other heavy falls as the trough moved east during the day. Normanton Airport registered 24mm in 52 minutes to midday, then 13mm in 14 minutes to 3.38pm, and there were a few heavy falls in the southeast (see downpours). Afternoon storms that developed around Darwin produced some locally heavy falls. Middle Point, 50km ESE of the city, recorded 33mm between 3 and 6pm, 22.8mm falling in 42 minutes.
SA: Whyalla has wettest day in two years: While the showers in the cold southerly stream over SA today were nothing special, they managed to give Whyalla Airport 19.0mm, its wettest day since 2 October 2003 when 26.5mm was recorded.