No one has heard from Céline Cremer since the middle of this month, even after her car was found at Philosopher Falls in the state's remote north-west near Waratah, about 130 kilometres west of Launceston.
Her family at home in Belgium were desperate for any sign of the fun-loving 31-year-old but on Thursday police had confronting news.
Based on expert advice, they said the recent conditions in the remote area were "not survivable for the length of time that Celine is thought to have been exposed in the wilderness".
Police highlighted freezing weather, snow and rain in the region.
Searchers on the ground, in helicopters and using drones had failed to turn up any sign of the missing woman by Thursday.
"At this stage police believe Celine's car has been in the carpark since at least 20 June, and our information indicates she was only equipped for a light day walk," police said.
"The search effort is continuing but we are dealing with extremely dense bushland and the challenging weather conditions are expected to worsen over the coming days.
"We remain in close contact with Celine's family, and our thoughts continue to be with them."
Earlier this week Céline's sister, Amélie Cremer, asked Tasmanians to do anything they could to help find the 31-year-old.
"The most difficult thing is the waiting," Amélie told 9News.com.au.
"We are helpless here and we just want to know."
Anyone with information should call police on 131 444.
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