At least one home has been destroyed by a tornado that whipped through northern NSW, and forecasters say wild weather will lash the state well into the morning.
A Bureau of Meteorology severe thunderstorm warning for large hailstones, heavy rain and strong winds was issued just before 11pm (NZT) on Saturday for the northern rivers, south coast and southern tablelands forecast districts.
Flash flooding and damaging winds could affect towns from Lismore, Byron Bay, Ballina, Kyogle, Batemans Bay and Moruya Heads for several hours, the bureau said.
One house in Tenterden, near Guyra, was razed in a tornado on Saturday afternoon.
Local resident Alexander Martin has told the ABC he watched the twister rip trees from the ground and destroy his 70-year-old neighbour's house.
Incredibly, she escaped injury.
"All of a sudden we heard this roaring ... it took her house and sheds out," Mr Martin said.
"The house has been totally wrecked and apparently she put a pillow over her head and got in the lounge room."
State Emergency Service spokesman Todd Burns told AAP this was the sole tornado spotted on Saturday, adding that it "ran out of puff" almost as quickly as it appeared.
"It seems like it was one of those localised events where the tornado just forms quickly, doesn't go very far and dissipates just as quickly," he said.
SES crews were kept busy across the state with almost 180 calls for help as winds downed trees and damaged roofs.
Mr Burns said the rough weather would keep emergency workers on their toes through the weekend.
"It's so unpredictable, the storm cells are forming out of nowhere," he said.