THE BUREAU of Meteorology is warning of heavy weather and possible flooding over the Australia Day long weekend.
On Friday Grafton was drenched with a short downpour of heavy rain, however further north the rain was much heavier in the inland areas of southern Queensland.
On Friday morning the Bureau of Meteorology issued a "heads-up," for the Northern Rivers Region.
Later at 3:20pm they upgraded to a severe weather warning.
The cause of all the rain is former tropical cyclone Oswald.
Oswald is forecast to gradually make its way down the North Coast on Sunday and Monday.
It could bring as much as 200mm of rain to the Valley with localised falls in excess of 300mm.
The Bureau said the rain may lead to flash flooding in the hardest hit areas.
The heavy rain is set to coincide with large swells and strong easterly winds along the coast.
Mayor Richie Williamson said the forecast is looking "fairly serious" but at this stage people should just be readying themselves for action.
He said an instant flood situation was unlikely but people on the land should be ready to move cattle and pumps to higher ground at short notice.
Cr Williamson also said Clarence Valley Council tested its entire flood infrastructure on Friday and crews have been placed on standby to deal with any issues should they arise.