NT, SA, VIC, NSW: Widespread record rain brings flooding. As the records section below shows, rainfall records tumbled across much of SA, western VIC and the extreme south of the NT in the 24 hours to 9am. The surface pressure charts and satellite cloud images below show the reason for the unusually widespread nature of the falls. The monsoon trough dips from the WA Kimberley to a deep low east of Alice Springs before arcing N and NE to more normal latitudes across Cape York Peninsula. Meanwhile, a complex Southern Ocean low moved SE close to the SA coastline today, dragging its attendant trough across SA and into NSW and VIC. Northerly winds ahead of these two troughs pulled monsoonal moisture into northern SA during Thursday, and on into southern SA on Friday and western NSW and VIC today. This plume of tropical moisture has been uplifted by the advancing southern trough, providing the trigger for the unusually widespread heavy falls and severe thunderstorms. The movement of the system has also been very slow, resulting in heavy rain falling for longer in any one location.
As the rainfall chart shows, a broad band through SA and western VIC received from 25 to over 100mm in the 24 hours to 9am as the uplift area passed. Heavy falls over 100mm fell in SE NT close to the monsoon low. For many locations in this broad area, these were the heaviest one-day rain totals in years, while a few locations received spectacular falls. Hawker, Georgetown, Mt Bryan, Port Pirie, Corny Point, Wolseley and Frances in SA and Coleraine in western VIC all had their heaviest January rain in over a century of records. Parawa in the southern Mt Lofty Range and Casterton in western VIC had their all-time heaviest falls in over 50 years. For the bulk of stations with shorter histories, their previous records were broken by substantial margins. See records for full details, which will be updated as the returns come in from postal-reporting stations over the next month or two. Wettest shows all totals of 50mm or more. Downpours provides details of some of the remarkable short-duration deluges, many from thunderstorms embedded in the rainband leading to flash flooding. Some of the more notable officially recorded cloudbursts in today's list include:
- Roxby Downs SA 24.4mm in 43 minutes (over twice their average January rainfall)
- Whyalla Airport SA 48mm in 3 hours
- Yunta SA 75mm in 6 hours (nearly 4 times their average January rainfall)
- Parawa AWS SA 60mm in 3 hours
- Coonawarra SA 53mm in 6 hours
- Hamilton Airport VIC 44mm in 6 hours
- Casterton 62mm in 4 hours
- As the rain area entered NSW later this afternoon, Broken Hill Airport recorded 33mm in 3 hours, 20.4mm of which fell in 22 minutes.
The cloud and rain also produced an exceptionally cold day. Top temperatures across much of SA were 8 to 11 below the norm.
While flooding has been widespread, farmers and firefighters are jubilant at the good falls which have improved pastoral and agricultural prospects and damped bushfires in many areas. Many dams in SA's Northern Agricultural District that have been empty for 5 or more years were full this morning.
Details of flooding:
- Dozens of homes were flooded in Port Pirie and Whyalla with emergency services responding to about 150 calls. Water caused over $100,000 damage to poker machines in one hotel. A train derailed near Port Germain on flood-affected track.
- Two days of torrential rain have created chaotic transport conditions in the state's central and northern areas. Most main roads north of the Eyre Highway are impassable or open only to high clearance vehicles, as well as most roads around Whyalla. The Eyre and Stuart Highways were both closed for a time. All dirt roads, including those to Innamincka, Oodnadatta and William Creek were impassable. Emergency services and police were conducting sweeps of main routes to find any stranded travellers.
AAP reported floodwaters up to 300m across cutting sections of the Port August to Lyndhurst road, which passes through Hawker. Cars, a tourist bus and over 20 road trains were stranded
- All roads into Hawker were cut after the town received 173.7mm in just over 2 days, nine times its average January rainfall. Emergency personnel had to be airlifted into the town, but this also was made difficult by low cloud. Remarkably, little structural damage was reported in and around the town. An evacuation order was issued for parts of the town this morning, but withdrawn as flooding receded and sandbagging and pumping proved successful. The town was expected to remain isolated for several days.
- An AAP press report said that 55mm fell in about 15 minutes at 6.30pm at Kaniva, 90km WNW of Horsham, leading to the flooding of over a dozen homes, the hospital, council offices and a football club. A roadhouse roof collapsed under the weight of water.
- The same report indicated 26mm fell in 20 minutes at Stawell. About 20 homes were flooded as well as a supermarket.
- Properties were flooded in Ararat.
- In Mildura, shops were flooded and motorists stranded by heavy rain mid-afternoon. Mildura Airport recorded 16.6mm in the hour to 3.30pm. There were also reports of flooded properties in Swan Hill.
- Flash flooding and trees downed by strong wind gusts caused traffic problems and accidents in Melbourne and Geelong, with about 50 emergency callouts.
- The rain, warmth and high humidity led to warnings of brown rot for fruit-growers in the northern, central and northeastern areas of the state.
- Emergency services in the state's west experienced the unusual situation of suddenly switching from several weeks of bushfire protection mode to dealing with flash flooding.
- Broken Hill SES received 111 calls for help after the onset of torrential rain about 4pm, mainly from properties including businesses in the city centre. Sandbagging was necessary to protect properties, as the city does not have a stormwater drainage system designed for rain this heavy. The Barrier Highway and the road to Silverton were closed by flooding.
NSW, VIC, TAS: Bushfire update. Tasmania's most popular bushwalking trail, the Overland Track, was reopened today after being closed yesterday. A fire started by lightning last Monday in the Fury Gorge west of Cradle Mountain has been contained by heavy rain overnight and today, with up to 50mm likely to have fallen in the area. Although it is estimated to have burnt through only 85ha, the Fury Gorge is among the most rugged and inaccessible landscapes in the nation. In VIC, although rain has damped down many firegrounds, the blazes near Tatong and Tambo Crossing (Great Divide southern complex fire) continued to burn outside containment lines. The Hermit Mountain fire, on the VIC/NSW border near Tom Groggin about 14km west of Thredbo, continued to pose a threat to the alpine village where 700 visitors were evacuated last Wednesday. It has so far burnt through about 44sq km. Light rain in both the VIC and NSW alpine regions frustrated backburning operations overnight.
WA: Cool in the south. A clear, calm night following yesterday's cool southerlies resulted in record low January minima in the state's South West and Great Southern. Pemberton and Katanning, both with half a century of observations, reported their coldest January night with lows of 4.0 and 5.4 respectively. Both minima and maxima today were 6 to 9C below average across large parts of southern WA.
QLD: Heavy rain on the central coast. Moist southeasterlies dumped heavy showers on the QLD central coast. Top falls to 9am were in the Pioneer River basin inland from Mackay with Mirani scoring 87.0 (see wettest), while during the day Woolshed, 35km WSW of Townsville, registered 89.4mm between noon and 4pm, 57.8 falling between 2 and 4pm (see downpours).
NSW: Cold surf for Sydneysiders. Persistent northeasterlies onto the NSW coast have caused upwelling colder water to move onto beaches around Sydney. Water temperatures are about 16C, 6 below average for mid-January.