A severe electrical storm has cut power to 11,000 homes in the NSW Illawarra and parts of western Sydney.
The system whipped up another impressive lightning show across the city on Tuesday evening and quickly dumped significant rain along its eastern suburbs about 7pm.
The weather bureau said 13mm fell at Little Bay in roughly half an hour.
Endeavour Energy said the wild weather had also damaged the network, with strong winds bringing down trees and branches over power lines and two lightning strikes on major substations.
Emergency crews had begun working to restore power to about 11,000 homes and businesses, describing the damage to the network as "extensive" and urging patience.
The highest wind speeds were recorded at Sydney Airport, where there was a gust of 91 km/h and over Sydney Harbour, where there was a gust of 89 km/h.
Bureau of Meteorology forecaster Rob Taggart said the storms had developed on a trough moving over the southeast of the state and gradually marched through the Illawarra and into Sydney.
"The storms were lightning active because it was pretty unstable above the surface, so that fosters electrification and that generates lightning," he told AAP on Tuesday evening.
A warm air mass also gave the storm some energy, however the bureau predicts Sydney should not experience storms again on Wednesday.
Parts of the northern ranges and northern inland, however, may be in for some wild weather.
The SES said it received 270 calls for help from 10am Tuesday but most were for minor damage including leaking roofs.