About 70 firefighters spent Sunday preparing fire breaks with heavy machinery and fire retardant drops from water bombers in the hope of containing the blaze.

The RFS has advised residents in the areas of Ellerslie, Darlow, Yaven Creek, Bangadang, Mount Adrah, Oberne and Toonga to prepare their properties for a bushfire.

Riverina Highlands RFS public liaison officer Peter Jones told The Daily Advertiser that the biggest threat on Monday would be from 60 kilometre-per-hour northerly winds potentially carrying embers outside of containment lines amidst 40-degree temperatures.

"The weather is going to put pressure on the south-eastern corner of the fire where there is a lot of activity going on and where we have had the Large Air Tanker working [on Sunday] to try and halt its progress."

The RFS called in a 737 jet water bomber along with four other aircraft and a helicopter to help establish containment lines around the bushfire, which was attended by 70 firefighters and earthmoving equipment.

Mr Jones said efforts by the RFS and Forestry fire crews to dig fire breaks and drop fire retardant from the air on Sunday had helped contain the bushfire.

"We have got a good line behind the homes on the eastern side and onto pastoral land," he said.

"Where the fire has come out onto the grass, the crews have managed to get on top of it.

"It's more about winds blowing a gale and any smouldering embers and leaf litter going across our control lines and onto neighbouring properties.

"We don't expect the fire to break out, we expect embers to blow across our tracks and we have to be vigilant that it doesn't get away from us."

Mr Jones said there was also a threat that forecast lightning storms on Tuesday would start new fires across the region.

The bushfire, which started on Saturday afternoon from a suspected lightning strike near Dunns Road, has also threatened significant powerline infrastructure.

"At the southern edge we have the NSW main interconnector for east to west and we are trying to make sure the fire doesn't impact on that," he said.

"At this stage we are holding it but if the fire impacts on that powerline, we could potentially lose half the power in the state if other infrastructure were to break as well."

The RFS issued an emergency warning for the bushfire on Saturday but later downgraded the incident to a 'watch and act' alert.

To stay up to date with the latest fire alerts, visit the NSW Rural Fire Service Fires Near Me website here.