Professor David Bowman on why downslope winds could cause fires in Tasmania

The winter fires in California have shocked the world. Read why a Tasmanian professor and fire expert says the state is not immune from similar dangers.

A beach house is engulfed in flames as the Palisades Fire burns along Pacific Coast Highway in Malibu, California. Photo by AGUSTIN PAULLIER / AFP

The Californian bushfires are a “preview of what can happen in Hobart”, a Tasmanian professor and one of the world’s leading bushfire scientists warns.

David Bowman, who has been studying fire ecology for more than 40 years and is Professor of Pyrogeography and Fire Science at the University of Tasmania, said the Santa Ana winds, called downslope winds, were “very fast moving dry winds”.

“A lot of Tasmanians don’t understand that the Derwent Valley and the Central Plateau are perfectly designed for these downslope winds, and it’s entirely possible to get a downslope wind that could blast a fire down the Derwent Valley or across the lower slopes of Mount Wellington,” he said.

“The reason we are so frightened of these downslope winds is the extraordinary speed that fires can escalate, and that’s because they’re being driven by very strong winds, which we’ve had in the last 10 years, these crazy winds, roofs off houses and boats getting torn adrift.

“It’s theoretically possible that we could get such a wind combined with high temperatures and a fire, so that’s the absolute scariest scenario.”

Bushfire expert Professor David Bowman at Knocklofty Reserve. Picture: Chris Kidd

Professor Bowman said the 1967 bushfires, in which 64 people died, had burned down to the beachside suburb of Taroona.

“Speaking as somebody who lives in Hobart, that is a really scary scenario. We have the climatology and we have the topography to have downslope winds that can be extremely dry and fast moving,” he said.

“We had such an event in 2006 which burned the eastern shore, and that was in October. But if we got something like that in February, it doesn’t bear thinking about.”

One of the most shocking images from the fires in Los Angeles, Professor Bowman said, was the traffic gridlock as people fled their homes too late.

He said “we’ve got to put our thinking caps on now” and think about how to deal with mass evacuations and the effect on the sick, elderly and pets because people often “dithered” about leaving their homes.

“People may have to leave on foot or on bicycles because we know a truck breaking down can cause traffic gridlock.”

Mercury Historical Archive image. 1967 Hobart bushfire disaster. The Taroona medical centre was left in ruins.

Professor Bowman said because of “brilliant weather forecasts” Tasmanians would be given two days warning that dangerous fire weather was coming.

“That’s when you really need to be focusing on getting the hell out of danger,” he said.

Professor Bowman stressed the importance of having a fire plan.

“Many people in suburban areas may not consider themselves vulnerable and might not have a plan at all,” he wrote in The Conversation.

“Many regional and rural areas in Australia have bushfire places of last resort – safe places for the community to go when all other bushfire plans have failed.

“The LA tragedy also shows we need these places in cities.”

Professor Bowman said insurance companies also “were scratching their heads” and thinking about the future.

He said he currently had a research project in California looking at housing loss during fires.