NSW: Heavy rain and flooding concentrate on South Coast

A low pressure system continued to move SE along a trough lying across the state today (See charts) crossing the South Coast during the early hours of the morning. Rain in the Central West generally eased as the low moved away, though there were still some heavy thunderstorm falls near the troughline, such as 53mm between 9am and noon at Narrabri Airport. As the low moved offshore over warmer-than-average waters, torrential rain began on the South Coast and Southern Tablelands, bringing the heaviest falls along the coast in at least three years and on the Tablelands the heaviest February falls in 10 years.

The highest falls are listed below, and are the totals recorded at 9am each day.

The recording time of 9am disguises the fact that most of the rain fell in a 12 to 18 hour period starting between midnight and 6am and finishing around 6pm today. A rainband moving in from the west during the early hours of the morning stalled over the South Coast between Moruya and Merimbula, then developed explosively during the late morning and moved northwards as the low pressure system deepened, giving several hours of torrential rain around midday. At Moruya Airport. 188mm fell between 3am and 6pm, but 131mm of this fell in the 5 hours to 3pm. Farther south at Narooma, heavy rain during the morning up to 9am produced 151.5mm, its wettest 24-hour February fall in 39 years. However, 98mm was recorded 9am to 3pm today, and further rain during the afternoon and evening pushed the 24-hour to 9am Tuesday total to 161.8mm, a new February record in 84 years of observation. Moruya Airport's 153.0mm to 9am Tuesday was its wettest day in 12 years of operation (See records for today and Tuesday for details of other records.)

The heaviest rain appears to have fallen between Moruya and Narooma. The automatic raingauges at Bodalla, 16km NNW of Narooma, and Barlows Bay, 5km NW of Narooma have breaks in their hourly reports at the critical times, but do have 24-hourly reports. By deduction, it appears that Bodalla recorded 138mm 9am to noon. Along with an actual measurement of 105mm between noon and 3pm, Bodalla recorded 243mm in the 6 hours to 3pm. Using the same processes, Barlows Bay recorded an assumed 25mm 9am to noon and a measured 132mm noon to 3pm for a total of 157mm. Given the serious flash flooding in this area, the figures seem credible. Both locations also received heavy rain between 9pm last night and 6am today with 129mm at Bodalla and 115 at Barlows Bay for the 9 hours.

Farther south in the Bega Valley, heavy rain began falling around 6am and continued through until around 6pm. Angledale, 6km NE of Bega, recorded 227mm over these 12 hours with 106mm falling between 1 and 4pm. Merimbula Airport broke its February 1-day rainfall record with 96.0mm at 9 this morning, then broke that again at 9 tomorrow morning with 101.0mm.

The deluge brought flash flooding from the Bega Valley north to Moruya. The Princes Highway was closed by floodwater in several places betwen Moruya and Narooma and also at Bega, The Cobargo to Bermagui Road was similarly closed, while the Snowy Mountains Highway was closed near Browns Mountain, west of Bega, due to a landslip. Numerous other roads in the area were closed, with police advising motorists to delay travel unless absolutely necessary. About 30 people had to be evacuated in Bega and Moruya.

The Eurobodalla Shire and Bega Valley were declared natural disaster zones on 16 February to enable Councils and other approved businesses and individuals to access funding for infrastructure repair. Early inspection indicates that one bridge has been completely washed away and a number of culverts damaged. On 17 February, the same declarations were made for the Central Darling and Cobar shires, where up to $6m damage had been caused to roads, bridges and causeways.

Despite the torrential rain, run-off into the major rivers caused only minor flooding due to relatively dry catchments. Minor flooding was reported in the lower Moruya/Deua system and the Bega River, reflecting the coastal nature of the heaviest rain.

Gale force winds whipped up by the deepening depression brought a forecast of damaging surf conditions between Ulladulla and Gabo Island.

Rainfall inland on the Southern Tablelands came from the passage of the low pressure system yesterday and early today, and spill-over rain across the ranges from the South Coast low today, and consequently tapered away westwards. So while Nimmitabel recorded 152mm for the 48 hours to Monday, Cooma recorded only 67.8 and Canberra Airport 95.4mm. This was still enough to cause concerns about flooding in the Cooma creeks and the Molonglo River, though flooding did not eventuate. A band of torrential rain moving from the southeast across Canberra between 8 and 9 this morning caused traffic chaos, flooding roads including the main Monaro Highway. NE of Canberra, Lake George, which has been dry since the late 1990s, was streaked with water today as its water table filled following around 150mm in the area in the past week.

Up to midday, the SES had received 1538 calls for assistance across the state, 1181 of them in the Sydney Metro area where there were general falls of around 100mm earlier in the weekend, and the Illawarra, where flash flooding was a problem.

VIC: Some heavy falls in Gippsland and the Otways. Spin-off rainbands from the NSW depression brought heavy rain to south-facing mountainous districts of Gippsland and the Otways, mostly in the 24 hours to 9 this morning. Average falls in Gippsland were 40 to 60mm, but in the mountains between Dargo and Licola Reeves Knob recorded 120mm and Mt Wellington 101. In the Otways, Haines Junction (Mt Sabine) topped the list with 106.6mm.

NT, QLD, NSW: Thunderstorms give impressive rainfall. The active trough lying across the NT Top End then trailing SE through central QLD into northern NSW gave scattered heavy falls in the 24 hours to 9am and again through today. In QLD, a dozen locations from the Central Highlands and Central West through the Darling Downs to the Far SW registered between 50 and 100mm to 9am (See wettest) while thunderstorms through the day gave Winton 46.6mm and Toowoomba Airport 35.6mm in 1 hour. In the NT, Borroloola recorded 68mm in one storm around 6pm of which 51.8mm fell in the hour to 6.30pm and 35.4 fell in 23 minutes to 5.53pm. In NSW, late morning storms gave Narrabri Airport 53.0mm between 9am and noon. Short duration rainfalls like these are given in the downpours secion below.

QLD: Rain hits vegetable production. Heavy rain in the Wide Bay agricultural area around Bundaberg is causing concern to fruit and vegetable growers, both for the local and export markets. Totals for the first half of February have already exceeded the monthly average, and in some areas doubled it. Bundaberg Airport, for example, had recorded 291.4mm to 9am 16 February compared to a February monthly average of 159.7. The rain has come right at planting time. The Bundaberg area is the major supplier for all Australia for tomatoes, capsicums, egg plant and zucchinis, and a major supplier of other fruit and vegetables. The rain is also a blow to Wide Bay area vegetable growers trying to develop an export market.

WA: Pilbara bushfire continues. A fire started by lightning on Friday in the Millstream Chichester National Park continued to burn today closing roads and camping sites in the area.

International Events

TONGA: Cyclone Rene batters island. Cyclone Rene hit the archipelago nation of Tonga early this morning with winds gusting to 228km/h according to the Tonga Meteorological Office quoted by Associated Press. Early assessments indicate the island got off lightly, with widespread but light building and infrastructure damage. However, most crops, including banana palms and fruit from mango and breadfruit trees, had been destroyed. Businesses, schools and government offices were closed for the day. Winds had decreased by this afternoon, but large parts of the archipelago expected to be without power or communications for up to a week.