What is a fire whirl (fire tornado) and what causes it to start?
A firestorm, fire tornado or fire whirl is a conflagration which attains such intensity that it creates and sustains its own wind system. It is most commonly a natural phenomenon, created during some of the largest bushfires, forest fires, and wildfires. A fire whirl is caused when a fire, under certain temperature and wind conditions, acquires a vertical spin and forms a whirl, or a tornado-like effect. A fire whirl can make naturally-occurring fires more dangerous. A strong updraft is the most important ingredient for developing a fire whirl. They are usually 10-50 metres tall, a few meters wide, and last only a few minutes. However, fire whirls can be several hundred metres tall and have winds up to 160 km/h. These phenomena aid in the ‘spotting’ ability of wildfires, thus leading to more damage.
