A fire which originated at Gell River, in the Franklin-Gordon Wild Rivers National Park, had burned over 15,000 hectares as of Friday afternoon, with a Watch and Act alert issued for Maydena, Tyenna, Mt Field, National Park, Bushy Park, Ellendale, Westerway and Fentonbury.

Two helicopters were used to evacuate campers from the area and walking tracks were closed.

It was caused by lightning from a storm on December 27, and started to spread again on Friday.

Some communities in the area were described as “very high risk” from being impacted by the fires late on Friday afternoon.

Winds carried the smoke from the fire over Hobart, causing an almost black sky at times. The Tasmania Fire Service issued a bushfire smoke alert for Hobart, the Derwent Valley and Huon Valley.

The smoke was unrelated to the diversion of flights from Hobart, however.

A Jetstar flight from Melbourne to Hobart was diverted to Launceston, and passengers were required to take the Redline overland.

A Virgin Australia flight to Hobart made an unsuccessful approach and diverted back to Melbourne.

Bureau of Meteorology senior meteorologist Luke Johnston said strong wind shears created hazardous conditions for landing aircraft.

“The cool change arrived an hour earlier than we were expecting in Hobart. It was obviously just a bit of a southerly surge that pushed up the Derwent just a little bit faster than we were expecting,” he said.

“Fresh to strong southerly winds right on the change and immediately following it caused a fair bit of wind shear at Hobart airport, so far there’s been one flight that’s been diverted elsewhere.”

Maximum temperatures in Launceston did not quite reach 30, but in the south of the state some areas pushed above 40 degrees, including Campania.

The afternoon change caused temperatures to drop by up to 10 degrees in just five minutes.

Mr Johnston said temperatures were likely to remain in the mid-20s for much of Tasmania for the coming weeks, with minimal rainfall.

“Once we get through today, we’ll have a relatively dry, fresh and gusty westerly stream, however... the temperatures will be much lower,” he said.

“We’re not going to see temperatures like this for at least the next week or beyond.”