Winds topping 130/km have lashed Tasmania's south, fanning fires and forcing passenger flights to be diverted.

Heavy winds have toppled power lines and blown sparks from planned burn-offs, starting around 15 fires, with nine tankers battling a blaze at Grass Tree Hill in Richmond.

Gusts up to 100km/h at Hobart also forced both Virgin and Qantas to divert flights back to Melbourne.

A Qantas spokesman said a Boeing 737 departing from Melbourne about 10am (AEST) had to be turned around, but was able to touch down in Hobart this afternoon.

The Bureau of Meteorology said gusts reached 135km/h in exposed coastal areas across south Tasmania mid-morning, with urban areas lashed with winds measuring 90-100km/h.

The bureau predicted the heavy winds would begin to die down by early evening.

Acting district officer for Tasmania Fire Service, Andrew McGuiness, said the fires were concentrated on the state's southeast, with a few scattered north along the coast.

Fire crews had the blazes under control by mid-afternoon.

"Most fires are small at this stage with brigades busy containing them but our efforts are being hampered by the severe winds," Mr McGuiness said.

The State Emergency Service (SES) says debris stirred up by the wind and falling trees and power lines have damaged properties from Huonville to Hobart and Richmond.

The SES and Tasmanian police took about 150 calls from residents reporting trees over roads and minor damage to properties between 8am and 2pm.

One of the most seriously damaged buildings was a structure at Hobart Racecourse which partially collapsed, a SES spokesman said.

The SES is warning residents to secure all loose items outside at their homes then stay indoors until the winds subside.

Police asked motorists to exercise extreme caution on exposed roads in affected areas.

AAP