Gillian Ballantyne, 50, disappeared from the Banknock area on Tuesday.
She is described as 5ft 2in, bald, with a slim build and blue eyes.
When last seen, Gillian was wearing jeans, a white jacket and a blue head covering. She does wear hats and scarves routinely and has been seen wearing a blue beanie.
She is believed to be in possession of a pink fleece and a brown scarf.
Specialist resources including the Air Support Unit and the Dive and Marine Unit have been involved in the search operation, with rescue teams spotted on a stretch of river in Allandale on Wednesday evening.
Officers’ inquiries have revealed that Gillian was last seen at about 12.45pm on July 6 on Napier Road, Wardpark Industrial Estate in Cumbernauld.
She is known to walk considerable distances and officers are checking relevant CCTV footage.
Chief Inspector Gill Marshall, Stirling Area Commander, said: “Officers and Gillian’s family are becoming increasingly concerned for her welfare.
“We know she enjoys walking and often walks considerable distances. I am appealing to anyone who may have seen Gillian to get in touch with us.
“In particular, if anyone has any dashcam footage and you were in and around the areas Gillian was seen, please can you check your device, as you may have captured an image of her which could assist our investigation.”
Anyone with relevant information is asked to call Police Scotland via 101 and quote incident number 3625 of Tuesday, July 6, 2021.