Mr. Concannon, who suffers from dementia and has difficulty communicating, has been missing since November 10th.
There have been a number of reported sightings of the 71 year-old but none have been confirmed.
Mr Concannon is described as being about 5'6" tall, of medium build and with grey hair. He was wearing a black and grey beanie hat, a black coat, checked shirt and navy trousers.
John’s brother Micheal Concannon is again asking people to help find him: