JOHNSONS LANDING, B.C. — Crews are keeping a close eye on the weather as it hampers search efforts for four people believed to be buried in a massive landslide in southeastern British Columbia.

Bill Macpherson of the Central Kootenay Regional District said the slope of mud, trees and other debris was deemed stable enough on Sunday for rescue workers to head back to the tiny community of Johnson’s Landing.

But Macpherson said with a thunderstorm warning issued and rain falling, weather conditions were unstable and there’s a chance efforts would be called off if the site shows any sign of instability.

Macpherson said geotechnicians are on scene to monitor the slide’s movements and make decisions regarding the safety of the operation as rescuers move through the debris.

“They’re doing a grid-style search and they’re focusing on the high probability locations where they hope to find these people, using GPS, mapping and the best information from local residents,” he said.

About 70 people from search and rescue, RCMP and other organizations have personnel participating in the search.

Police dogs were also expected to return to the site Sunday.

At least three homes were crushed by the slide in the tiny hamlet on the shores of Kootenay Lake northeast of Nelson on Thursday.

Lynn Migdal, who now lives in Florida, has identified the missing as her 17- and 22-year-old daughters Rachel and Diana Webber, along with her ex-husband Val Webber.

A female German tourist is also believed to have been caught in the debris.

The Ministry of Forests said on the weekend that it had received an email from a Johnson’s Landing resident the morning the slide occurred expressing concern about a mountainside creek.

In the email the woman, whose name was not released by the ministry, said she noticed “surges of chocolate-coloured water that came down Gar Creek,” each bringing down a significant number of logs and debris and causing a jam.

“As soon as the log jam formed, gravel began to be deposited behind it,” she said. “The entire level of the creekbed has now been raised at least (1.8 metres) in that area.”

The woman wrote later the whole creek was flowing over and down her driveway and made reference to a conversation with a friend with search and rescue experience who told her to stay on high ground.

Hours later, the mountainside gave way.