Yes. Tornadoes can occur in almost any country, and a few have been known to cross national borders.
Russia does get tornadoes. One tornado that struck Russia in 1984 may have been an F5. Tornadoes are a product of thunderstorms, which require warm, moist air. Since much of Russia has a rather cold climate, it does not get tornadoes often. Additionally, tornadoes hitting Russia are not often heard of outside of Russia because few tornadoes anywhere are significant enough to gain international attention. Finally, Russia has vast expanses of unpopulated land, where tornadoes that do occur are unlikely to be reported.
It is a matter of intensity. Not only are tornadoes not as common in Australia, but they are generally not as strong. The strength of tornadoes is rated on the Fujita scale, which has six categories, ranging from F0 for the weakest tornadoes to F5 for the strongest. Australia rarely gets tornadoes stronger than F2. Such tornadoes can cause fairly significant damage, but don't wipe out entire neighbourhoods and rarely kill. By contrast, the United States usually gets at least several F4 tornadoes every year and gets F5 tornadoes every few years. These are the tornadoes that cause the catastrophic damage that makes national and international news.
The Us st still has tornadoes. In the old days, areas hit by tornadoes were usually helped by nearby communities in rescue and recovery. More recently, areas that suffer major damage as helped by federal and stated funds, insurance agencies, and organizations such as the Red Cross. International aid has never been significant in regard to tornadoes in the US.
Tornadoes in the U.S. are called tornadoes.
Tornadoes are sometimes divided into "weak" tornadoes "strong" and "violent" tornadoes. Weak tornadoes are those rated EF0 and EF1. Most tornadoes are weak. Strong tornadoes are those rated EF2 and EF3. Violent tornadoes are those rated EF4 and EF5. They are the rarest of tornadoes, only about 1% of tornadoes are this strong.
There are a few reasons why we rarely hear of tornadoes in other countries. First of all, the United States actually does get more tornadoes, and particularly more strong tornadoes than any other country due to the climate setup in the central parts of the country, which is ideal for tornadoes. This is particularly true of the very violent tornadoes that cause significant enough damage to be picked up by national and international news networks. Less significant tornadoes sometimes get mentioned, but such mention is usually only brief.Another reason is that the Unite States has the best system of documenting tornadoes. The next highest rate of violent tornadoes appears to be in India and Bangladesh where there is no documentation system for tornadoes. This moves on to the next point of ethnocentrism: news networks will generally take more interest in events that occur in developed nations, and especially in their own nation. So tornadoes that occur outside the U.S. will get less coverage by U.S. news networks.
It depends on what you mean by extreme. Tornadoes of EF4 and EF5 tornadoes, however are often referred to as violent tornadoes. These account for about 1% of all tornadoes.
Tornadoes don't get named, Hurricanes do, but Tornadoes don't.
Florida frequently has tornadoes, though several states have more tornadoes annually.
No. Tornadoes are dangerous.
Yes, some strong tornadoes create brief satellite tornadoes that circle the main funnel.
Antarctica is the continent that does not have tornadoes. Tornadoes typically form over land, so the cold and uninhabited nature of Antarctica makes it unlikely for tornadoes to occur there.