The most devastating tornadoes are usually the ones rated F5 or EF5. Tornadoes of this intensity have been known to obliterate entire neighborhoods and kill dozens. Examples of especially devastating tornadoes of such intensity include the Moore, Oklahoma tornado of 1999 which killed 36; the Hackleburg, Alabama of 2011 which killed 72; and the Joplin, Missouri tornado of 2011 which killed 158. Occasionally an F4 or EF4 tornado makes it onto the list as well, such as the Wichita Falls, Texas tornado of 1979 which killed 42, and the Tuscaloosa, Alabama tornado of 2011, which killed 64.
Definitely rain. Rain usually does not have any harmful effects unless it causes flooding. Tornadoes however can always cause damage, although most often it is relatively minor, all too often tornadoes are devastating.
Yes, tornadoes are a serious threat to Illinois. Violent tornadoes (EF4 or stronger) are a farily regular occurence in Illinois. These are the tornadoes that are known for devastating communities.
Twister
Tuscaloosa, Alabama has been hit by a number of tornadoes, but the most recent and most devastating tornado to hit the city was the EF4 that struck on April 27, 2011.
There are no names for tornadoes. The name of a hurricane is retired if the storm is particularly devastating.
There frequently are. However most tornadoes happen over water and don't have a devastating impact, so they don't make the news (these tornadoes are called "waterspouts"). However, most weather agencies do not include waterspouts in official tornado counts unless the hit land. However, the have been a few incidents in which 100 or more tornadoes occurred in 1 day. Most notably on April 27, 2011 an 209 tornadoes touched down, mostly in the U.S. in the largest tornado outbreak ever recorded.
This cannot be answered simply, as both hurricanes and tornadoes vary greatly in how bad they are. The impacts of both tornadoes and hurricanes can range from negligible to devastating. That said, the very worst hurricanes can be far deadlier and more destructive than the worst tornadoes.
Most tornadoes happen in spring and summer
Tornadoes can be devastating to vegetation and man-made structures, but the ground itself is usually not affected in any significant way except in the most violent tornadoes. In rare cases tornadoes can be stroung enough to scour away the soil.
Most tornadoes occur in spring.
Tornadoes are most popular in the Midwest.
Most tornadoes occur in spring and summer.