Intense, isolated weather systems have created wild weather on the state's Mid North Coast and in Sydney's West, with palm-sized hailstones falling in some areas.
The most intense hail was seen in the Macleay Valley between Coffs Harbour and Port Macquarie, but the hail also fell as far south as Bulahdelah.
The Bureau of Meteorology reported hail at Penrith in Western Sydney.
It started off quite light and then got heavy. Our lawn had a blanket of hail and looked like it had snowed, according to Bulahdelah resident Joanne Rose.
Ms Rose said the hail fell for a short but intense period.
It came quite suddenly. She said that the weather in Bulahdelah today has been a little touch and go.
Then we heard some thunder and within a few minutes the hail began. The hail that fell in Bulahdelah was large enough to be gathered in a bag by Ms Rose and her children.
Steve Lawrence, SES community capability officer for the region, said so far only a small number of calls for assistance had been made.
He said that he had a couple of requests for assistance in the area of trees that have fallen and damaged property.
There has been no flood rescues which is very pleasing. Lawrence said that the main concern in the coming days was low-lying communities prone to flash flooding.
Areas that traditionally see water over roads with these types of storm events that we've seen over the last couple of days have seen very heavy downpours, he said.
It can lead to flash flooding in a short period.
The Bureau of Meteorology senior meteorologist Jordan Notara said supercells were a possibility in some parts of the state for the rest of the day, with a severe thunderstorm warning for parts of western Sydney and Illawarra at 5: 30 pm.
He said there were thunderstorms that could potentially fall into that category.
There were concerns also for the Mid North Coast, said Notara.
He said that the storms continue to be quite active.
While they are moving offshore in many areas, we are still seeing some lingering storms in its wake, particularly in areas west of Port Macquarie. A low was on the coast, which would bring windy and wet conditions on Thursday, according to Mr Notara.
No major damage has yet to be reported.