What is the difference between the tornadoes in USA and Australia
Although here's a long-standing myth that Australia doesn't get tornadoes, it simply isn't true. Actually, Australia gets tornadoes, they are a bit different than those in US.
The Australian tornadoes form and collapse in the space of about 10–30 minutes, but they are pretty dangerous too. Just read the recap by BoM Australia of a tornado that took place last Saturday near Bendigo, Victoria.
The Bureau has confirmed that a tornado near Bendigo, Victoria, last Saturday was at least EF2 intensity on the Enhanced Fujita scale (with wind gusts in excess of 200 km/h), after meteorologists visited the site yesterday to assess the damage. A house was flattened, big trees were snapped in half and debris flung in multiple directions. We're glad everyone is safe.
Known as a "coldie"—a cold season tornado—these events are caused by cold fronts sweeping up from the Southern Ocean. They consist of rotating columns of air that move across the ground at 50–80 km/h, with typical damage paths being anything from less than a kilometre to several kilometres long and very narrow.
Unlike the tornadoes of the United States which can exist for hours, travel hundreds of kilometres and occur mostly during the warmer months, coldies form and collapse in the space of about 10–30 minutes.
Enhanced Fujita Scale
EF0 105–137 km/h Light damage
EF1 138–177 km/h Moderate damage
EF2 178–217 km/h Considerable damage
EF3 218–266 km/h Severe damage
EF4 267–322 km/h Devastating damage
EF5 >322 km/h Incredible damage
Australia sees around 30–50 tornadoes per year, but most of them are in areas with very low population. Australia has had some very strong 'F4' (Fujita scale 4) tornadoes, for example in Queensland in the 1970s–80s and in Bucca, Queensland, in the early 1990s, and an F3 tornado in Mulwala, Victoria, in March 2013.
However, it's unusual to see such a strong tornado this time of year. The USA, due to different atmospheric conditions there, sees around 1200 tornadoes per year—of which one or two might be rated EF5 on the enhanced Fujita scale.
Images: BoM Australia