The east coast of Australia looks set to face a spring heatwave this weekend, with unseasonably high temperatures predicted for the capitals of Melbourne, Sydney and Brisbane.

Saturday’s weather looks set to behave like a typical summer’s day with Melbourne facing a top of 29C before a change sweeps through in afternoon squalls. Brisbane’s predicted top is 31C while Sydney is facing two days of 33C, with the potential for the temperature to hint 40C for the first time in September.

Don’t be fooled by the early morning cloud. Penrith and Richmond in the city’s west have predicted tops of 37C.

A high pressure system over the northern Tasman Sea, in combination with a complex low pressure system south of the Bight, is drawing hot air into New South Wales from central Australia. Later today, the Bureau of Meteorology expects a cold front to move into state’s southern and western districts.

The BoM is warning of damaging winds in western New South Wales this afternoon from a strengthening northwesterly airstream ahead of a cold front, expected to reach the state’s southwest this evening. Gusts in excess of 90 km/h are possible and alpine areas above 1900 metres in the state’s southeast could see damaging winds averaging 70 to 80 km/h, with gusts to 110 km/h.

A fire weather warning has been issued for the Greater Hunter, Greater Sydney Region, Illawarra/Shoalhaven, Central Ranges, North Western, Lower Central West Plains, Northern Riverina, South Western and Far Western fire areas. Severe fire danger is forecast for all those regions.

Sydney’s weather will be hot once the morning cloud has cleared, with a mostly sunny afternoon. Winds northwesterly 20 to 30 km/h increasing to 25 to 40 km/h in the middle of the day then tending northerly 15 to 20 km/h in the evening. Sunday’s forecast is 33C again and windy.

Western parts of the state are facing temperatures in the mid to high 30s, with Tibooburra in the northwest forecast to hit 40C in a very hot and windy Saturday.

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