Thousands of homes remain without power after a powerful storm lashed the New South Wales central coast region yesterday.

The SES received 625 calls for assistance with fallen trees, branches and powerlines coming down on roads and houses mostly across Sydney, the central coast and the Hunter.

Hail, heavy ran and gusts of wind up to 109 kilometres an hour battered the region, leaving over 20,000 homes in eastern New South Wales without power earlier this morning.

Ausgrid received more than 400 reports of dangerous hazards on the network including fallen wires and trees damaging power lines.

Storm timelapse from the Bureau Forecasting Centre in Sydney this afternoon #SydneyStorms #NSW pic.twitter.com/VhfROEPwIP

— Bureau of Meteorology, New South Wales (@BOM_NSW) February 17, 2017

Multiple lightning strikes and falling trees caused serious damage to electrical infrastructure.

“Crews will be working as quickly as they can but it is likely that some small pockets of areas and some individual customers will be without power well into the weekend, possibly into Sunday,” Ausgrid spokeswoman Phillipa Wheeler said.

“Crews have to go to those sites and make sure that area is safe for the public to be around, there is obviously live electrical equipment that we need to make safe if wires are on the ground.

“So once crews have made the area safe, they’ll work to get the power on as quickly as they can.”

Sydney’s west was one of the hardest hit, and Canada Bay SES Unit Deputy Controller Bill Hoyles said it was the worst storm he had seen in 17 years on the job.

Multiple lightning strikes from Sydney storms. Stay clear of fallen powerlines. For outage updates go to https://t.co/MxbaFPxBlK pic.twitter.com/8QQUOpCgXo

— Ausgrid (@Ausgrid) February 17, 2017

“We’ve had some really big trees come down across backyards down on roofs, a lot of roof damage,” he said.

“With such a large number of jobs it may take time to get to some of those jobs, but we will get round to you as quickly as we possibly can.”

The Bureau of Meteorology is forecasting similar severe storm conditions today.

Residents are being advised to clean gutters, remove outside furniture, place cars under cover and shelter inside with any pets when the storms hit.