Residents living near the Narrabri racecourse have been told to evacuate as floodwaters continue to rise in the northwestern NSW town.

The NSW State Emergency Service issued an updated evacuation order on Wednesday and it has positioned relief assets in Narrabri and nearby Wee Waa.

Narrabri was the subject of an emergency warning on Wednesday with homes and businesses expected to be impacted by mid-afternoon.

The Narrabri Jockey Club’s racecourse is located in a low-lying area of the township. Flooding impacted the track in April.

In the Hunter Valley, flooding continues to ease but there are still more than 46 warnings current for residents across the Mid North Coast, Upper Hunter and New England regions. 

Racing in the regions has been affected but Tamworth, a 2-½ drive south of Narrabri, will stage a meeting on Thursday that was transferred from Quirindi.