Police say they believe Nicola Bulley “sadly” fell into a river as they focus on a 10-minute window from 9.10am to 9.20am when the dog walker went missing last Friday.
Officers said the mother-of-two has not been found despite an extensive search of the area in Lancashire, along the River Wyre and 15km (nine miles) to the sea.
Police said an unprecedented amount of resources had gone into the search for Ms Bulley.
Latest updates from the police news conference
Speaking at a news conference, Superintendent Sally Riley gave an update on what Ms Bulley was wearing when she disappeared, including an ankle-length black quilted gilet jacket, and a black Engelbert Strauss waist-length coat, which was worn underneath.
She said officers were trying to trace her clothing and accessories and urged people to look out for the items.
Along with the coat and gilet, Superintendent Riley said the 45-year-old woman was also wearing tight-fitting black jeans, long green walking socks tucked into her jeans, ankle-length green Next wellies, a necklace and a pale blue Fitbit.
She said: “It’s really important that the public pay heed to those very specific clothing descriptions please, because factual sightings of those items would be very useful to us.”
Ms Bulley was last seen on 27 January at about 9.10am on a path by the River Wyre in the village of St Michael’s on Wyre.
Her phone was found on a bench still connected to a work call, while her springer spaniel dog was running loose.
A search is continuing, with Ms Bulley’s friends retracing her route earlier on Friday – marking a week from her disappearance.
Her partner, Paul Ansell, has said he will “never lose hope”.
He also said he kept playing “every scenario” in his head “around and around” and that his focus was on supporting their two young daughters.
Mr Ansell said: “I don’t know how I am coping. I don’t want to think about that. I am just focused on the girls.”
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‘I don’t know how I am coping’
He went on: “We’re never, ever going to lose hope, of course we’re not, but it is as though she has vanished into thin air.”
Ms Bulley, a mortgage adviser, had dropped her daughters, aged six and nine, at school shortly before she vanished.
