The low pressure system off Queensland's Sunshine Coast is forecast to move slowly southwards today, reaching the Gold Coast area Sunday evening.

The Bureau of Meteorology say the system is very likely to remain close to the coast, and has some potential to be slightly inland as it moves south into NSW overnight into Monday morning.

The low is expected to move more rapidly southwards on Monday.

Thw warning for heavy rainfall is still present which may lead to flash flooding for the Northern Rivers throughout the remainder of today and into Monday morning.

The Bureau has released its flood estimates for Wilsons River with rainfall expected to intensify this afternoon.

River level rises have already been observed upstream of Lismore, including at Repentance, The Channon and Nimbin. Forecast heavy rainfall is expected to cause further river level rises into Monday, with possible major flooding along the Wilsons River at Lismore Monday afternoon or evening.

A Severe Weather Warning for heavy rain is current for the Northern Rivers.

Wilsons River:

The Wilsons River at Lismore (AHD) is expected to exceed the minor flood level (4.20 m) overnight Sunday into Monday.

The river level is likely to exceed the moderate flood level (7.20 m) Monday morning and may reach the major flood level (9.70 m) Monday afternoon or evening.

Major flooding possible along the Wilsons River at Lismore.

Further rises are possible with forecast rain.

The State Emergency Service advises that people should:

* Don't drive, ride or walk through flood water.

* Keep clear of creeks and storm drains.

* If you are trapped by flash flooding, seek refuge in the highest available place and ring 000 if you need rescue.

* Be aware that run-off from rainfall in fire affected areas may behave differently and be more rapid. It may also contain debris such as ash, soil, trees and rocks.

* After bushfires, heavy rain and the loss of foliage can make the ground soft and heavy, leading to a greater chance of landslides.

* Stay vigilant and monitor conditions. Note that the landscape may have changed following bushfires.

* For emergency help in floods and storms, ring your local SES Unit on 132 500.

The next Severe Weather Warning will be issued by 5:00 pm AEDT Sunday.

For more emergency information, advice, and access to the latest river heights and rainfall observations and forecasts:

* NSW SES: www.ses.nsw.gov.au

* RMS Live Traffic: www.livetraffic.com

* Latest River Heights and Rainfall Observations: www.bom.gov.au/nsw/flood/northcoast.shtml

* Latest NSW Warnings: www.bom.gov.au/nsw/warnings/

* Rainfall Forecasts: www.bom.gov.au/australia/meteye/

* BOM NSW Twitter: www.twitter.com/BOM_NSW