Detective Sergeant Lucy Aldridge said police would be flying a drone over the Riccarton and Hagley Park areas between 8am and midday on Thursday.
“We do not know where she travelled to after the Chateau and have not been able to locate any items that would lead us closer to her,” she said.
“We have grave concerns for Lis, and sincerely hope the use of a drone will help us find her.”
Aldridge said Nicholls’ family were desperate to find her.
The 79-year-old was wearing navy blue jeans, a black-and-grey-checked, long-sleeved shirt with a long-sleeved maroon top underneath and black leather shoes and she has distinctive long blonde/white hair.
She had been admitted to the facility for respite care on the same day she disappeared.
Aldridge urged anyone in Riccarton and the wider area to review any CCTV footage and check places where Nicholls might have taken refuge.
Police asked anyone who saw Nicholls to ring 111 immediately and use the reference number 250604/5465.
Non-urgent information could be provided online at 105.police.govt.nz, using “Update Report” and quoting the same reference number.
– RNZ