FIRE authorities say a large bushfire is out of control in Tasmania and will impact the township of Richmond.

An emergency warning has been issued for Middle Tea Tree Road in Richmond, northeast of Hobart.

An alert from the Tasmania Fire Service says that under these conditions the blaze will be uncontrollable, unpredictable and fast moving.

It says the fire is expected to put the area of the Richmond township and surrounds at direct extreme risk from the fire front.

Ten fire trucks have been sent to the blaze, which is expected to put the township of more than 800 people at extreme risk of fire within 15 minutes.

The fire danger rating in the region is extreme.

A total fire ban has been declared for the entire state tomorrow as firefighters prepare for the worst bushfire danger in the area in more than five years.

Residents in the area have been told to leave as the safest option, but only if the path is still clear.

If it is too late to leave, residents have been advised to stay inside their homes until the fire has passed by.

Tasmania Fire Service Chief Officer Mike Brown says the conditions across the state are the worst he's seen since the 2006/2007 fire season, when bushfires burned near Hobart's eastern shore.

He added that the "wait and see" approach is too dangerous.

About 50 people had been evacuated or were in the process of being evacuated from the Richmond cabin and tourist park, according to ABC radio in Hobart, which described the scene as "pretty chaotic".

About 30 firefighters are battling the blaze with a police roadblock in place.