Man shot by police in northern NSW

A man has been shot by police in NSW after he allegedly lunged at officers with a knife.

Police were called to a home in Waterview Heights, west of Grafton, in the early hours of Wednesday morning following concern for the 36-year-old's welfare.

He lunged at officers with the knife upon their arrival, police say.

The man was flown to Gold Coast University Hospital in a critical condition.

A critical incident team will investigate the circumstances of the incident.