The Bureau of Meteorology has issued a Severe Weather Warning for the Northern Rivers.

At this time the warning just misses Lismore but does include the coastal towns of Evans Head, Ballina and Byron Bay.

The warning is for very heavy rain over the next 6-7 hours which may lead to flash flooding.

This warning is for Lismore & surrounds to be alert in case conditions change in the next few hours, to 9 am Lismore Airport received 5.6mm.

A low-pressure trough lying along the New South Wales coast is generating widespread and persistent rain in many eastern districts, along with windy conditions. This trough, in conjunction with a strong high to the south, is also bringing windy weather to higher parts of the southern ranges.

Most parts of the warning area will see the heaviest rain during the next 12 to 18 hours, however, some places may continue to experience periods of heavy rain through to Monday or Tuesday.