The dust storm spread from Broken Hill across to Nyngan, Parkes and Dubbo on Sunday, leaving many residents in complete darkness.

Towns including Nevertire and Narromine were also left without power "for hours".

"2020 — the year of dust! The worst dust storm we have had to date," Nevertire Hotel publican Harriet Gilmore said.

"Complete darkness, no power for hours.

"And this is the fourth one this week."

Locals were left frustrated, saying another forecast for rain had proved wrong.

"Next time they forecast a storm, I'll know just to assume a dust storm," Collie resident Jason Herbigg said.

Locals urged people to remember the rain had missed most of western New South Wales.

"Do not for one second think that the drought is over, because some of the state has had a drop of rain," Dubbo resident Erinna Colton said.

Dust storm an enduring symptom of the drought

The BOM said Sunday's dust storm was similar to those experienced in the Middle East.

"This dust storm was pretty similar to what we call an atmospheric gravity current. There, it's called a haboob dust storm," said forecaster Abrar Shabren.

While yesterday's storm was a visual spectacle, it wasn't unique, Mr Shabren said.

"Winds in Dubbo gusted up to 107 kilometres an hour," he said.

"In the past, similar storms have impacted the coast and reduced visibility there."

He said dust storms were an enduring symptom of the drought

Dust was more likely to be picked up by wind in sparsely vegetated areas where the soil was very dry.

"With a strong wind it raises the dust and it is elevated high up into the atmosphere," Mr Shabren said.

Without more rainfall, he said, further dust storms would likely impact communities in western NSW.

Where will the dust go?

University of Sydney soil expert Stephen Cattle said it was possible the dust stirred in Sunday's storm would lap the globe.

"Dust particles the size of a fibre of wool are small enough to travel several hundreds of kilometres.

He said particles even finer than that could go around the world in air streams until they were rained out.

"At the least, I would expect to see some fine grains head across to New Zealand and sit on their glaciers, as we have seen happen.

"Nature is a very powerful beast," Associate Professor Cattle said.

'Zero visibility in less than a minute'

The wind peaked at 7:45pm in Dubbo with a gust of 107 kilometres per hour.

"The dust storm was moving fast and was so thick that it went completely dark, [resulting in] zero visibility in less than a minute," Dubbo resident Jenny Duggan said.

Macquarie Anglican Girls School in Dubbo made a call to the SES after the school's roof was damaged in the storm.

Principal Craig Monsour expected the clean-up would take a full week.

Students will return to the campus next week to begin their school year.

"We're very glad for the help of the SES, who responded to call-outs and came in to make the school as safe as possible, as soon as possible," he said.

A total of 2.2 millimetres of rain fell in Dubbo after the storm passed — although Cowra has received 34 mm in the last 24 hours