The Big Brisbane Storm

Destructive Microburst

November 16 2008

After two days of hot and humid weather, plus a trough moving in from the Darling Downs, conditions were ripe to spawn severe thunderstorms in south east Queensland. By late afternoon on Sunday 16^th November winds backed to south-east and thunderstorm cells were spawned at the NSW border and rapidly moved towards Brisbane where at 4.48pm a destructive ‘microburst’ struck The Gap with hailstones.

A microburst is an intense, sharply defined column of sinking air that affects a relatively small area and produces abrupt ‘wind shear’ similar to but distinguishable from tornadoes which generally have convergent damage. Microburst downdraughts constitute a major hazard for aircraft when landing or taking off, and are known to have been responsible for at least thirty accidents in the United States.

The Bureau’s Doppler radar at the time of the microburst at The Gap measured 176 km/h. Emergency Services were kept busy after the storm lashed Brisbane. Technical Rescue personnel were involved in a swift water rescue in an attempt to save two people trapped in a water drain system. All attempts to save one of the men failed. He died at the scene. His companion was rescued.

In the severe storm 4000 homes were reported damaged, with 300 homes estimated to be significantly damaged and 30 homes were deemed unliveable. 145,000 homes and businesses lost power at the height of the storm.

The track of the Severe Storm was from the NSW border, through the Gold Coast area and on to Redbank Plains where it interacted with another storm forming a new storm that moved northwards toward The Gap and subsequently the Sunshine Coast.

Although the microburst was not a tornado its destruction was the equivalent of a tornado registered as an EF2 on the Enhanced Fujita Scale.