Australia Storm Hammers Sydney, New South Wales; Flooding Washes Away Homes

Jon Erdman
Published: April 21,2015


 

A slow-moving storm has hammered parts of eastern Australia's New South Wales province with damaging winds and destructive flooding.
The BBC reported that three people were found dead in the town of Dungog. Homes were swept away as over 12 inches (312 millimeters) of rain in just 24 hours swamped the town of about 2,100 residents 135 miles north of Sydney, according to the Australian Bureau of Meteorology (BoM).
New South Wales Fire and Rescue ushered four people trapped in a flooded home and local government urged residents of Dungog to evacuate to a local high school, if possible, due to the severe flooding.
Numerous locations near the coast in New South Wales picked up another 100 millimeters – just less than 4 inches – of rain since 9 a.m. local time Tuesday, on top of heavy rainfall from Monday. The BoM continued flood warnings for stretches of eight rivers in the province, including the Williams River near Dungog.

The East Coast low also battered the Sydney metropolitan area with an incredible 33 straight hours of sustained winds over 30 miles per hour and frequent gusts over 50 mph from mid-afternoon Monday through midnight Tuesday night. A peak gust to 83 mph was clocked at Norah Head and Wattamolla, according to the BoM.

Joggers struggle against sand whipped up by strong winds at Bondi Beach in Sydney on April 21, 2015. Sydney and surrounding areas were lashed by wild weather with trees felled, thousands of homes without power, schools shut and huge sea swells that hampered cruise ship movements.
((Peter Parks/AFP/Getty Images))

The high winds downed trees, some onto homes, and knocked out power to 215,000 customers, the largest outage in the region in eight years, according to WeatherWatch. New South Wales' transport minister urged no unnecessary travel in the city of Sydney during the storm.
These persistently strong onshore winds lead to significant coastal flooding and beach erosion, with local media reporting a 36-foot wave off the coast east of Sydney.
A Carnival cruise ship was forced to remain offshore of Sydney Harbour by the storm, stranded in 25-30 foot swells, reports the Sydney Morning Herald.
The high winds whipped beach sand into drifts, trapping some vehicles at Sydney's famous Bondi beach, forcing closure of the popular beach destination.
An estimated 7-8 inches of sand was blown off Sydney area beaches during the storm, a Surf Live Saving New South Wales spokesman told the Daily Telegraph.

Surface pressure (color contours), infrared satellite, and surface winds of the New South Wales, Australia storm on April 20, 2015. Purple streamlines show areas of strongest onshore winds.

The culprit for these impacts was an area of low pressure aloft that became trapped to the north of the active jet stream. That trapping lead to the slow-movement of the storm.
This closed-off upper-level low then induced a low-pressure center just off the New South Wales coast. The pressure gradient between that surface low and high pressure centered near Tasmania and the Tasman Sea lead to the intense onshore winds.
This storm should slowly wind down by later Wednesday into Thursday, local time.
According to the BoM, these East Coast lows occur several times a year off the eastern coast of Australia, somewhat akin to nor'easters along the U.S. East Coast.
They are most common in the fall and winter, with a peak occurrence in June. An Aug. 5, 1986, East Coast low wrung out 12.91 inches (328 millimeters) of rain at Sydney's Observatory Hill, an all-time daily record, there.

MORE: New South Wales, Australia Storm Photos