Sydney Harbour Bridge disappears in a thick blanket of fog

Thick fog blanketed Sydney this morning, causing havoc to roads and public transport services.

The reduced visibility made road conditions dangerous across the city, with drivers urged to take extreme care.

Ferries between Huntleys Point and Parramatta ran at a reduced speed due to low visibility, while services were cancelled from Pyrmont Bay and Cockatoo Island to Circular Quay.

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The fog came as a broad low and pool of polar air generates rain and showers in parts of New South Wales, Victoria and Tasmania, with snow falling on many parts of the Victorian and NSW ranges.

READ MORE: Clean-up begins after wild Victoria storm

Yesterday Sydney shivered its way through its coldest day in 37 years.

Elsewhere in NSW, blizzards dumped more than half a metre of snow over parts of the state over the last 48 hours, as towns and cities shivered through record-breaking temperatures.

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Orange received its heaviest dump of snow since 2015 yesterday, with a whopping 16cm.

In Victoria, the State Emergency Service has received almost 6000 calls for help in just 24 hours.

The influx of calls came after an intense low-pressure system ripped trees from the ground and knocked out power to some 290,000 homes in Victoria.

This morning, there were more than 2000 active incidents and more than 100,000 homes were still in the dark without power.

A trough crossing western and southern Western Australia is causing showers today.

A ridge of high pressure is keeping elsewhere mostly clear.