The New South Wales Rural Fire Service has warned residents they "may not get help" on Tuesday as blazes rage across the country.
A terrifying cocktail of raging wildfires and worsening weather conditions in Australia is heading for Sydney and the Blue Mountains, authorities have warned.
Three people have already died in the fires and New South Wales Rural Fire Service (NSW RFS) has said that high temperatures, strong winds and low humidity are making conditions even more dangerous, with the situation getting increasingly worse and expected to peak on Tuesday.
Firefighters have told people to take action now because they "may not get help" on Tuesday.
"Catastrophic is the highest level of bush fire danger. Homes are not designed to withstand a fire under these conditions," they said.
The "catastrophic" notice has been issued for Greater Sydney and Greater Hunter, including the Blue Mountains and central coast areas.
Even larger swathes of the country's most populous state are expecting severe and extreme fire dangers. A statewide "total fire ban" is place for Monday and Tuesday.
The NSW RFS wrote on Twitter: "Tuesday 12 November will be a dangerous day. Widespread areas of severe and extreme fire danger.