Essential Energy says it's unsure when the lights will come back on for about 1150 customers in Narromine, Warren and Walgett shires who lost power in the last 24 hours.

Heavy storms sweeping through the Western Plains have, as at 3pm, cut power in Walgett, Cumborah, Trangie, Narromine, Nevertire and surrounding areas, according to an Essential Energy spokesperson.

The spokesperson said 18 power poles have been brought down by storms near Nevertire, along with "widespread damage" to powerlines and other network components.

"Helicopters are helping to patrol the electricity network and damage is significant," the spokesperson said.

"Crews are working to carry out repairs and restore supply for customers if safe to do so, where possible, however work is being hindered by challenging access to some locations.

"At this time, there is no estimated time for power restoration for those customers without power."

Unplanned outages on Essential Energy's outage map as at around 4:45pm on 10 February. IMAGE: Essential Energy

The most recent outages hit less than 24 hours after 13,000 customers lost power during the height of the storms last night.

In that period, around 2600 customers in Narromine were affected, along with 2500 in Cobar, 1500 in Nyngan, 1500 in Bourke and 1300 in Warren.

By 2am this morning, power had been restored to most customers in that round of outages.

Meanwhile, an update issued at around 4:20pm by the SES said likely heavy rainfall may lead to flash flooding, large hailstones and damaging winds in the Walgett, Coonamble, Nyngan, Cobar, Bourke, Lightning Ridge and Brewarrina areas over the next several hours. 

"The public is reminded to always stay at least eight metres away from fallen powerlines or damaged electricity equipment and to call Essential Energy immediately on 13 20 80 or Triple-0 if the situation is life-threatening," and Essential Energy spokesperson said.