There is little chance of finding a missing elderly woman alive after she went bushwalking in the NSW Blue Mountains two weeks ago, police say.

Up to 150 people have been searching for 77-year-old Elizabeth O'Pray every day since she failed to return to her Medlow Bath home on March 7.

Police have deployed thermal camera-equipped helicopters, sniffer dogs and trail bikes in what they describe as an "exhaustive" search for the avid walker and highly regarded local.

The search has now been scaled back.

"We've been over walking tracks in the area several times and now with the advent of wet weather, it's proving too dangerous to continue to send large search teams," Assistant Commissioner Denis Clifford said on Monday.

An army of volunteers had rallied behind the operation since day one, turning out in droves to search and refusing to give up hope, police told AAP.

"On behalf of Ms O'Pray's family, the community and police, who have the highest regard for the local identity, I particularly want to thank the volunteer searchers for their efforts," Mr Clifford said.

The search will continue in isolated areas with specially trained personnel.

Police have appealed to the public for any vision, including still pictures and dash cameras, taken around Medlow Bath, near the Hydro Majestic, between March 7 and 9.

Rescuers spoke to Ms O'Pray on her mobile the day after she went missing and she is believed to have told them she was lost.

Days later, a local resident thought he heard a voice calling for help from the valley below Peckman's Plateau.

Ms O'Pray has suffered a stroke in recent years which has left her with memory loss.