Police, aided by search and rescue teams including from Australia, have spent the last week meticulously going through thousands of missing persons reports filed by worried family and friends.
On Thursday, police said that number had dropped dramatically, with "an additional 145 police staff and the Eagle helicopter" in the region.
The death toll remains at 11, with no new deaths recorded since Sunday.
Adding to the difficulty, poor weather has landed on the east coast of North Island, home to the hardest hit regions from the storm.
Weather forecasters MetService have issued an orange warning for Hawke's Bay, warning it could be hit by up to 200 millimetres of rain over 48 hours to Saturday.
Poor weather forced Prime Minister Chris Hipkins to abandon an attempt to reach Wairoa on Thursday.
The northern Hawke's Bay town was cut off from the rest of NZ when landslips cut off all approaches by road, with emergency supplies flown in by the defence force.
Mr Hipkins' NH90 helicopter ride from Napier lasted 10 minutes before low cloud dashed his hopes of travelling further.
The MetService warning specifically mentions the Esk Valley, where two dozen Australian search and rescue workers are helping to find missing people.
Hawke's Bay urban search and rescue team leader Ken Cooper told TVNZ conditions were tough.
"It's very challenging for our search crews, very challenging for the search and rescue dogs that are working in there, so hot conditions during the day," he said.