AUSTRALIA Day barbecues are likely to be rained out in most parts of northern NSW as ex-tropical cyclone Oswald pays little attention to the national holiday.
Heavy rains and gale-force winds that have battered the NSW northern neighbours are expected to cross the border on Saturday morning.
Bureau of Meteorology NSW Director Barry Hanstrum said the low pressure system had the potential to cause major flooding in rivers between the Queensland border and Hunter Valley.
Widespread heavy rainfall of up to 22mm is expected in north on Australia Day and will track south to the Mid-North Coast on Sunday.
Mr Hanstrum said communities at risk included Ballina, Byron Bay, Grafton, Coffs Harbour and Port Macquarie.
"Gale force winds will produce high seas and damaging surf conditions, with coastal erosion possible in vulnerable areas from Sunday," Mr Hanstrum said
"The rain and wind will ease from most areas on Tuesday as the low tracks eastward, but dangerous surf will continue into Wednesday."
Families planning to travel on the long weekend are being urged to pay attention to media updates.
NSW SES Commissioner Murray Kear said it was likely roads in impacted areas would be cut off by floodwaters and families if it was necessary.
He said campers in particular, should move to higher ground during the severed weather as there was potential for low-lying areas to be inundated.
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