Australia–– A firestorm that sprung from a devastating 2003 bushfire in Canberra, Australia, has been called the world’s first confirmed case of a fire tornado.
The twister packed horizontal winds “in excess of 250 km/h [155 mph]” with vertical speeds “at 150 km/h [90-95 mph]”, the Australian ABC News website said.
“Our analysis indicates that the tornado had a rating of at least a two on the enhanced Fujita scale of tornado severity,” lead researcher Rick McRae said, quoted by ABC.
A wind speed above 155 mph is marginal between F-2 and F-3 on the Fujita-Pearson tornado intensity scale.
McRae, of the Bushfire Cooperative Research Centre, made the distinction between fire whirls, which are fairly common, and this full-blown tornado, which was apparently anchored to a parent thunderstorm.
The tornado had a basal diameter of “nearly half a kilometer [third of a mile]” as it neared the outskirts of Canberra.
Pine plantations were felled, houses were unroofed and cars were blown of the road, according to McRae.
The fire claimed the lives of 4 people and destroyed 491 houses. The failure was in the forest areas.Advertisement
Following a 10-year strategy, ACT fire managers have created a mosaic across the landscape of different fuel levels, burning at every opportunity.
But forests have been too wet to burn this spring and the past two summers.
A network of 500 fire trails and strategic burns along the north-west urban edge, heavy grazing and extra grass slashing will create a fortress for the territory which forecasters say faces a higher than average risk this summer.
After a fire-fuelled tornado in January 2003 killed four Canberrans and frightened thousands more, CSIRO fire expert Phil Cheney told the subsequent inquiry the fire’s penetration into urban areas under extreme conditions did not reflect a failure of fuel management on the urban interface.