The NSW State Emergency Service (SES) has issued a warning about possible minor to moderate flooding for the Wilsons River catchment and Lismore later today. 

The SES warns that flooding of the Wilsons River catchment is possible because catchments are currently saturated after the rainfall over the last few weeks. 

The flood warning comes as the Bureau of Meterology (BoM) this afternoon issued a severe weather warning – predicting heavy rainfall about the Northern Rivers district with potential to cause flash flooding this evening.

The rainfall is associated with a slow-moving low pressure trough bringing a humid and unsettled air mass into northeastern parts of the state.

This potential for heavy rainfall is expected to continue into Thursday morning, before easing by Thursday afternoon.

Localised intense or very heavy rainfall, though a small risk, is possible with embedded thunderstorms, and may result in more dangerous flash flooding if they eventuate.

The State Emergency Service advises that people should:

* Not 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.

What to expect from Flood Watch warnings

Minor flood levels 

Low-lying areas next to water courses are inundated. Minor roads may be closed and low-level bridges submerged. In urban areas inundation may affect some backyards and buildings below the floor level as well as bicycle and pedestrian paths. In rural areas removal of stock and equipment may be required. 

Moderate flood levels  

In addition to the above, the area of inundation is more substantial. Main traffic routes may be affected. Some buildings may be affected above the floor level. Evacuation of flood affected areas may be required. In rural areas removal of stock is required. 

For more information, visit http://www.bom.gov.au/water/floods/floodWarningServices.shtml

FloodSafe advice is available at www.ses.nsw.gov.au 

For life threatening emergencies, call 000 immediately 

For more information: 

• Listen to your local ABC radio. 

• Flood preparation advice www.ses.nsw.gov.au 

• Road information, for local roads contact Council or log onto www.myroadinfo.com.au

• Road information on State Government managed roads go to the Live Traffic NSW website at http://livetraffic.rta.nsw.gov.au 

• Rural animal and livestock assistance contact your Local Land Services Office

• You can find more information on the severe weather warnings and river levels from Bureau of Meteorology website at www.bom.gov.au