Incident Inspector Roger Robinson said: “Concern is increasing for Joan as we believe that she has been upset recently.
“A thorough search is being carried out in the local area with assistance of the National Police Air Service helicopter. She doesn’t have a car so may be travelling on foot or public transport.
“We are now becoming very worried for her safety and I urge her to get in touch as soon as possible – we simply need to know that she is safe and well.”
Joan is described as white, with short grey hair and of medium build and normally wears glasses. She may be wearing denim jeans.
Anyone with information or knowledge as to Joan’s whereabouts should call Dorset Police on 101 quoting incident number 21:121.