Looks like it's Tassie's turn to worry about Fire Bugs. 

Residents have been evacuated from about 50 homes in and around Lefroy as a large bushfire threatens the north Tasmanian township.

The 672-hectare fire is north of Lefroy between Beechford Road and Douglas Road, with emergency services warning the area could quickly become under threat.

The Tasmanian Fire Service said the fire would be difficult to control and burning embers would threaten homes ahead of the main fire.

People with unprepared homes should go to a safer location, but only if the path is clear.

Acting deputy regional fire chief Neil Brookbank said an evacuation centre was being set up at George Town Memorial Hall at Regent Square.

"The residents in and around Lefroy need to ... monitor ABC radio and also monitor our Tasmania Fire Service website in case conditions change," he said.

"Currently the Lefroy township is being impacted by smoke and embers.

"Some residents have chosen to leave the area on their own accord."

Road closures are listed on the Tasmania Police website.

The blaze broke out in bushland near Musk Vale road last night and is being fanned by strong winds.

Earlier, police and fire crews were door-knocking the small town of Lefroy, telling residents to prepare to evacuate.

Mr Brookbank said firefighters were doing all they could to contain the blaze.

"Our resources are being deployed to protect assets in and around Lefroy and along the Beechford Road, and we've also got helicopters water bombing."

Hundreds of homes in the area have lost powers as a result of the blaze.

TasNetworks said the power outages affected 700 homes in Beechford, Bellingham, Lefroy, Lulworth, Pipers River and Weymouth.

Crews were unable to give an estimation of when power would be restored.

Many locals in the path of the fire had already packed and were ready to go, including Vonda Jenkins, who lives near Curries Dam.

Photo: Fire crews are expecting conditions to worsen as winds pick up in Tasmania's north. (ABC News: Damian McIntyre)

"Plans in place, yep, [I've] got things packed," she said.

"Just grabbed a few essentials that I need, and my dogs, mainly, but yeah I'm fine."

Earlier TFS spokeswoman Linda Robbins said helicopters were water bombing the area.

"The winds are just starting to increase," she said.

"We're expecting the winds to increase steadily throughout the afternoon, which is another reason that we need people to make sure they monitor the ABC radio and the TFS website."

Bulldozers were building containment lines around the fire.

The cause of the blaze is not known.

K.J.