Australia Weather News

Thousands of homes and businesses in Sydney's west will remain without power overnight, following a severe thunderstorm which brought heavy rainfall and damaging winds.

Areas affected included Penrith, Mt Druitt and The Hills, with heavy rain and strong winds bringing trees down on homes and roads.

The Bureau of Meteorology (BOM) issued a more general severe thunderstorm warning on Wednesday evening as the storm moved north.

Becky Gollings from the State Emergency Service (SES) said they had responded to hundreds of calls for help after the severe storm warning was issued, and the number rose as residents came home from work.

"It was pretty chaotic with those severe thunderstorms affecting Sydney and further south on the Illawarra and south coast," she said.

Endeavour Energy said more than 33,000 homes and businesses in Western Sydney suburbs from St Marys through to Mt Druitt and the Hills District were left without power during the severe weather.

More than 14,000 of those were in the Plumpton area, after a lightning strike hit a major substation.

As of 9:30pm more than 13,000 homes and businesses were still affected at suburbs in and around Mt Druitt, The Hills district and around Parramatta.

Endeavour Energy said because of widespread damage, some customers would be without power overnight until repairs could be completed.

"Residents in these areas are asked to check on elderly or sick neighbours and [are] reminded not to touch or go near fallen powerlines, keep others well clear and call Endeavour Energy immediately on 131 003 [if they see one]," it said in a statement.

It said all planned maintenance in Western Sydney had been cancelled and fresh crews would be brought in from the Blue Mountains, Liverpool and Wollongong to assist.

Flight delays averaged 30 minutes during storm peak

Sydney Airport said at the storm's peak several flights were cancelled and both domestic and international services experienced delays, but services were now back to normal.

Forecaster Zac Porter said the storm produced some fairly heavy rainfall as it came into the Sydney area.

"Around the Warragamba Dam area we have had falls of up to 20 millimetres in just 15 minutes and also in other parts of the state today with thunderstorm activity we have seen winds gusts of over 80 kilometres per hour," he said.

Earlier in the afternoon, Cowra, in the state's central west, recorded wind gusts of 87kph and a gust of 85kph was recorded at Goulburn in the Southern Tablelands.