THE battered suburb of Kurnell, in Sydney’s south, is in shock tonight as it tries to pick up the pieces after a devastating double whammy of severe storms that led to hail the size of cricket balls, a tornado reaching gusts of over 200km/h and several people hospitalised.

Police have said it was only good fortune that prevented serious injuries across the city while a metrologist said the weather event was “dangerous” and highly unusual in the way it formed.

A little mild drizzle turned into a ferocious storm at around 10.30am this morning tearing roofs from homes and businesses in the south of the city before rattling the CBD and heading north towards the Hunter. Barely three hours later, an already shaken Sydney was pummelled once again with the eastern suburbs, including busy Bondi Junction, being hit the hardest.

At one point this afternoon three severe thunderstorms were stalking their way around Sydney.

By midafternoon police had one simple message for those people whose suburbs had been affected by the storms: go home.

Fearful of traffic chaos as commuters clog up flooded streets and roads strewn with debris, NSW Police advised people to end the day as soon as possible.

In the devastated southern suburb of Kurnell, the NSW Riot Squad has been called to help distressed residents access to their homes.

Police said the squad’s four wheel drive vehicles were proving vital to get in and out of the shattered suburb which was hit by tornado force winds. The road into the peninsula suburb is now open again but only to residents.

Fire and State Emergency Service crews have gone from house to house to check on people after tornado strength 200km/h winds tore through the suburb, the area now being declared a disaster zone.

Kurnell local Melanie Bowman said tiles had come off her roof and powerlines were down.

“I can see the sky from our garage ... I can see lots of parts of roofs in the street,” she said.

“It felt just like a cyclone with hail and high winds.

“My husband has left to come home from work and he can’t actually get out here.”

The emergency services said they had received 400 calls while 25 homes on the Kurnell peninsula have suffered “extremely significant damage”. Fifteen fire crews were in attendance in the suburb.

A 40-year-old man in Kurnell suffered head injuries after reports of storm damage to a building while a 38-year-old man was treated for shock and another patient was treated for an unspecified condition. A 75-year-old woman received cuts to her leg, while a man was struck by debris and an elderly man was treated for anxiety. But despite the destruction, there had been no serious injuries. Inspector Winston Pisani said “It’s very fortunate no one got hurt given the damage we’ve seen.”

Some 7000 businesses are without power, including Kurnell Public School, and many homes are without roofs. Ausgrid has said emergency repairs to the low and high voltage network in the area is expected to continue until tomorrow. An evacuation centre for Kurnell residents has been set up at the Cronulla Leagues Club.

SUPER CELL

“It is what’s called a super cell thunderstorm and they’re one of the most dangerous thunderstorms we get,” the Bureau of Meteorology said.

Severe thunderstorms hit central Sydney, Sydney Airport and waters off Bondi Beach again around 1.30pm and Sydney Olympic Park and Wyong at around 2pm. Destructive winds and heavy rainfall were followed by flash flooding particularly in the city’s east with part of the roof of the Westfield Bondi Junction shopping centre caving in leaving the ground floor covered in water. A shopper was treated for minor injuries after being hit by debris at the mall.

Police have said motorists should avoid Bondi Junction altogether due to the storm damage.

The BoM has said while the threat of severe storms has eased, major thunderstorms are still a real possibility and warnings remain current for the Mid North Coast, Hunter, Central Tablelands, Central West Slopes and Plains, Australian Capital Territory and parts of the southern Tablelands, North West Slopes and Plains, South West Slopes, Upper Western, Snowy Mountains and Northern Tablelands districts.

Earlier in the day, a wind gust of 213km/h was reported at Kurnell at around 10.30am.

It's hailing golf balls at Cronulla pic.twitter.com/giSDUCHku3 — eesha (@voidhoran) December 15, 2015

Severe Weather Forecaster at the BoM, Michael Logan, said the storm was out of character as it began in the morning, not the afternoon, and because it came from the sea to the coast and didn’t develop over land.

“The storm situation today was dangerous and relatively unusual, due to the storms’ strength, the time of day they occurred, their direction of movement, and the probable occurrence of tornadoes,” he told news.com.au.

“The intensity of the storm as detected on radar combined with the wind gust at Kurnell suggest a tornado was likely associated with this very severe thunderstorm.”

The desalination plant in Kurnell was evacuated after reportedly sustaining significant damage and workers were also cleared out of the Caltex refinery.

Water half a metre deep has also been reported near Cronulla High School with live wires down.

Sydney airport was closely monitoring the storm activity with passengers being advised to check flight details with their airlines, an airport spokeswoman said. Flights from Melbourne and the Gold Coast are among those delayed by Qantas, Virgin Australia and Jetstar.

Sydney tornado sends objects flying One Sydney local captured the incredible gusts created by a tornado that's sending objects flying in Kurnell. Courtesy: Instagram/@andymacphotos

Transport for NSW said buses in and around Kurnell and the city’s east were being delayed due to flooded streets.

Beth, who lives and works in Cronulla in the city’s south, said “golf ball-size hail” fell on St Andrew’s Anglican Church.

“We had some brownouts, lots of thunder and lightning, and some large hail,” she said.

“The wind was strong and it was hitting our glass windows. I have a big dint in the front of my car.”

Truck has been tipped onto its side due to strong winds, #Kurnell. Further emergency services being diverted to area pic.twitter.com/YUdVqMyUHR — SutherlandShireNews (@SShireNews) December 16, 2015

Photo just taken of damage in #Kurnell - trees, wires down in the area. Roofs have been ripped off homes. pic.twitter.com/KGl0YguOEU — SutherlandShireNews (@SShireNews) December 16, 2015

6cm diameter hail in Cronulla. Photo via Lilly Rowan. Latest warnings: https://t.co/pDZkYbkdGS #7News pic.twitter.com/vm8VPG9pvy — 7 News Sydney (@7NewsSydney) December 16, 2015

The SES said people should move cars under cover or away from trees, secure or put away loose items around the house, yard and balcony, keep clear of fallen power lines, creeks and storm drains and don’t go through flood waters.

It also said to avoid using phones during the storm, stay indoors away from windows, and keep children and pets indoors.

Warwick, in south west Queensland’s Darling Downs has also been hit by storms and heavy rain.

For emergency help in floods and storms, phone the SES (NSW and ACT) on 132 500.

— with AAP