Sydney, Storm Season Is Here
The SES has received 250 calls for assistance after severe thunderstorms and large hailstones lashed Sydney, the Hunter and mid-north coast regions overnight.
Severe squalls and "dangerous" supercells delivered destructive winds, heavy rain and hailstones up to five centimetres in width in some areas.
"Most calls are for leaking roofs from hail damage and fallen trees and branches," SES spokesman Phil Campbell told AAP.
"The number of calls for assistance will climb well over 250 by lunch time."
Sydney metro, Lake Macquarie, Newcastle and Maitland, and the mid-north coast up to Forster were the areas most heavily hit by the storms, he said.
Passengers travelling on the Central Coast and Newcastle Line are advised to allow plenty of extra travel time due to urgent power supply repairs caused by weather conditions at Narara.
Trains are still running between Sydney and Newcastle Interchange but major delays are expected, said Transport Management Centre.
The storm activity is expected to ease by lunchtime on Friday when the system moves out to the Tasman Sea, Bureau of Meteorology meteorologist Gabrielle Woodhouse told AAP.
With a sunny weekend on the cards, Mr Campbell urged NSW residents to get outside and clean their gutters before the next storm in a week or so.