Wild weather has battered the east coast with the federal government declaring a natural disaster. (Dean Lewins/AAP PHOTOS)

Thousands are without power, communities are at the brink of isolation, and a tropical cyclone is looming as Australians battle a week of wild weather that has been declared a natural disaster.

Wind gusts of up to 100km/h throughout the week left more than 100,000 Sydney customers without power, and 40,000 were still without electricity on Saturday morning, Ausgrid said.

Another 12,000 customers were without power in Newcastle and the Hunter regions, along with 8000 in Port Stephens.

Thousands are without power, communities are at the brink of isolation, and a tropical cyclone is looming as Australians battle a week of wild weather that has been declared a natural disaster.

Wind gusts of up to 100km/h throughout the week left more than 100,000 Sydney customers without power, and 40,000 were still without electricity on Saturday morning, Ausgrid said.

Another 12,000 customers were without power in Newcastle and the Hunter regions, along with 8000 in Port Stephens.

On Friday afternoon at least two people were injured when a large fig tree in Hyde Park crashed to the ground across a footpath and onto a busy street.

Two people suffering minor injuries were transported to the nearby St Vincent’s Hospital for treatment, a NSW Ambulance spokesperson said.

Earlier in the week a man in his 80s was killed when a tree fell on his car overnight in the state’s central west.

Federal Emergency Management Minister Jenny McAllister declared the wild weather a natural disaster, opening up disaster payments for families and businesses affected.

“The assistance activated today will ensure communities can access essential supplies and accommodation and ensure councils can start clean up and repairs,” Minister McAllister said.

“This is a time when individuals need to think about their own risks and listen to advice.”

Heavy rainfall and damaging winds are set to continue on Saturday morning but ease off in the afternoon, according to the Bureau of Meteorology.

Rainfalls up to 120mm could fall in alpine areas across NSW.

Hazardous surf warnings will remain in place for the Sydney and Illawarra coasts.

In Western Australia, a tropical low is likely to from north of Pilbara, with a high chance of becoming a tropical cyclone.

Damaging winds may develop on coastal and island communities between De Grey and Dampier from early Sunday, extending to Exmouth on Sunday night.

While the expected cyclone will move offshore before it develops, large waves could cause minor flooding between De Grey and Exmouth.