BOM forecasts heavy rain for parts of NSW, SES urges residents to prepare

The SES says residents should be prepared for flash flooding when the rain arrives on the weekend. (ABC Central West: Mollie Gorman)

Parts of northern New South Wales that flooded twice earlier this year are forecast to miss the heaviest rainfall from a weather system that could bring "a month's worth of rain in a few days" to some parts of the state, the Bureau of Meteorology says.