A severe weather warning has been issued for the southern ACT, the Snowy Mountains, and the South Coast.
A cold front will bring winds of up to 90kmh on Tuesday afternoon, the Bureau of Metereology said. The warning does not cover the suburban parts of Canberra.
"Vigorous northwest to westerly winds will affect elevated areas and their immediate downwind slopes," the bureau said.
"Strong winds averaging 50 to 60kmh with gusts to around 90kmh are possible from Tuesday afternoon for parts of the Snowy Mountains district, southern parts of the ACT, as well as elevated areas further east from the Central Tablelands to inland of the South Coast."
Canberra has a 90 per cent chance of around 5 millimetres of rain, with storms likely in the afternoon.
The weather warning has also been extended to the Central West and Blue Mountains, including Lithgow and Katoomba.
The front will move across NSW and ACT from June 11 to June 12.
Thredbo, Jindabyne, Mount Ginini, Bowral, Braidwood, Bombala, Adaminaby and Nimmitabel are urged to be on alert.
Damaging winds with gusts of around 130kmh are possible in alpine areas above 1900 metres from the morning of June 11.
Winds are expected to ease over alpine areas early on June 12, but may continue over the eastern half of the warning area until late afternoon.
The Australian Alps can also expect up to 20 centimetres of snow, according to Snowatch, with temperatures hovering around freezing for the rest of the week.
Emergency services are urging people to secure loose items on their property, move vehicles away from trees, and report fallen power lines immediately to providers.