Dozens of flights have been grounded in Melbourne and Sydney as wild winds lash Australia's south-east.

Thirty-one domestic flights have so far been cancelled out of Melbourne, mostly because of the weather. No international flights have been affected at this stage.

Several Jetstar domestic flights have been cancelled. Credit:Rob Homer

Both Melbourne and Sydney airports have just one runway open for domestic flights, meaning fewer planes can land.

Qantas said it had cancelled about a dozen domestic flights by early Friday afternoon.