Two tornadoes, record-breaking rain and large hail have hit New South Wales in the 24 hours to Thursday morning, as supercell thunderstorms and a band of rain sweep the state.
Heavy downpours triggered a surge in calls for assistance.
Andrew Edmunds, a spokesperson for the State Emergency Service, said crews had responded to “a large volume of incidents” with more than 850 calls for assistance in a 50-minute period around 8.30pm on Wednesday. Crews responded to about 600 incidents.
A number of vehicles were caught in flash flooding, including a light rail vehicle stuck on Anzac Parade.
“Crews brought 20 to 30 passengers to safety, and also used an Ark Angel raft to ferry an elderly passenger across some of the water,” Edumunds said.
The SES also assisted about 10 passengers from a bus, one of a number of vehicles that “came into strife with the heavy rain”.
At least two tornadoes touched down on Wednesday afternoon – one near Young in the state’s south-west, and one near Caragabal, about 400km west of Sydney by road.
Tornadoes are fairly unusual and particularly rare in NSW, said Angus Hines, a senior meteorologist at the Bureau of Meteorology.
They form from supercell thunderstorms, Hines explained, where a column of rising air spirals northwards and creates a vortex, which – when the conditions are right – can then spiral down and eventually touch the ground.
On average, Australia experiences 60 to 80 tornadoes a year, he said.
“A lot of those go pretty much unnoticed because they occur over very sparsely populated places. And a good chunk of them happen in the far southwest exposed coasts of Western Australia.”
The tornadoes were only one aspect of this week’s severe weather, which also saw record-breaking rain, large hail and strong winds in parts of the state.
Several Sydney suburbs saw their highest September rain in the 24 hours to Thursday morning, as a band of heavy and persistent wet weather “set up shop” over the NSW coast, impacting areas including Sydney, Wollongong, the Illawarra and down to the south coast.
In Sydney, 122mm of rain was recorded at Observatory Hill weather station, making it the city’s second highest September rainfall on record. The last time the site recorded rainfall close to this figure was 110mm in 1883 – the daily record is 144.5mm on 10 September 1879.
According to the BoM, several other sites recorded their highest September daily rainfall by 9am Thursday:
Collaroy (Long Reef golf glub): 108mm
Sydney Botanic Gardens: 116mm
Rose Bay (Royal Sydney golf club): 110mm
Randwick (Randwick St): 145.8mm
Marrickville golf club: 81mm
Peakhurst golf club: 113mm
Cronulla South bowling club: 147mm
Campbelltown: 99mm
Camden airport: 77.8mm
The highest fall was 181mm at Greenwell Point, 93km south of Wollongong.
“Quite a lot has happened over that last 24 hours,” Hines said on Thursday morning. “NSW has had, maybe not every flavour of severe weather, but certainly a good selection.”
Multiple severe weather warnings remained in place on Thursday, including alerts for damaging winds and hazardous surf across New South Wales.
The SES continued to monitor for minor flooding along several rivers, which could lead to local road closures.
A group of hikers were rescued at Wattamolla, south of Sydney, after heavy rainfall hit from 1pm on Wednesday. On Thursday at 7am, wind speeds of 100km/h were recorded at the coastal picnic area.
Conditions were expected to ease on Thursday, although several warnings remain in place, including for damaging winds in parts of the Hunter, Mid North Coast , the Northern Tablelands and Lord Howe Island.
Damaging wind gusts with peak speeds of 90km/h were expected to last into the afternoon due to a complex low pressure system, the Bureau of Meteorology said.
Large and powerful south to south-east waves are forecast to batter the northern and central coasts through to early Friday, bringing hazardous surf and increased risk of damaging waves and coastal erosion.
NSW police marine area command advised people to consider staying out of the water and avoid walking near surf-exposed areas.
