Fire Whirl
ADDPMP804A fire whirl consists of a burning core and a rotating pocket of air and can reach up to 2,000°F (1,090°C). Most of the largest fire whirls are spawned from wildfires; they form when a warm updraft and convergence from a wildfire are present. They are usually 10–50m (33–164ft) tall, a few metres (several feet) wide and last only a few minutes. Some, however, can be more than 1km (0.6 miles) tall, containing wind speeds over 200km/h (120mph) and persisting for more than 20 minutes. Fire whirls can uproot trees over 15m (49ft) tall. These can also aid the “spotting” ability of wildfires to propagate and start new fires as they lift burning materials such as tree bark. These burning embers can be blown away from the fireground by the stronger winds aloft.
There are currently three widely recognised types of fire whirls:
● Type 1: stable and centred over the burning area.
● Type 2: stable or transient, downwind of the burning area.
● Type 3: steady or transient, centred over an open area adjacent to an asymmetric burning area with wind.
An extreme example of a fire whirl is the 1923 Great Kantō earthquake in Japan which ignited a large city-sized firestorm which in turn produced a gigantic fire whirl that killed 38,000 people in fifteen minutes in the Hifukusho-Ato region of Tokyo. There is evidence suggesting that this fire whirl was of type three.















































































































































































































































































































































































































































































































































































































































































































































































































































