Sydney was battered with rain and lightning on Wednesday afternoon, causing power outages, and the NSW SES has warned further storms could hit the east coast on Thursday.
Ausgrid said about 1000 homes lost power around Hornsby in northern Sydney and a further 500 homes in Dural were also affected after lightning moved across Sydney.
Around 150 homes in the city's hills district were still without power on Thursday morning after fallen trees and flooding took out hundreds of power lines across the city and the Hunter from Saturday onwards.
On Wednesday, a woman was issued with an infringement notice after she drove into floodwaters in Sydney's west and became stuck, endangering herself and the two little boys who were in her car.
Police were called to Grange Avenue, Schofields, on Wednesday night after the 61-year-old's vehicle, carrying two boys aged five and nine, became trapped in floodwaters after she tried to cross a bridge.
The metre-deep water prevented her car from moving. Officers towed her car to safety and then issued her with the Traffic Infringement Notice.
Hawkesbury Police Area Command's Inspector Garry Sims says motorists must use caution during and after wet weather.
"You can never truly tell how deep floodwaters are and it's not worth the risk trying to drive through them," Inspector Sims said.
"If there is heavy rain ahead, or the roadway is flooded, pull over in a safe place and wait for the floodwater to recede or find another way to your destination."
Dust was also whipped up by thunderstorms at Dubbo earlier in the afternoon.
