1.龍捲風是怎樣形成的? 2.龍捲風有什麼影響? 3.怎麼躲避龍捲風?

1.Definitions


Occasionally, a single storm will produce more than one tornado, either simultaneously or in succession. Multiple tornadoes produced by the same storm are referred to as a tornado family.
Tornado outbreak
Occasionally, several tornadoes are spawned from the same large-scale storm system. If there is no break in activity, this is considered a tornado outbreak, although there are various definitions. A period of several successive days with tornado outbreaks in the same general area (spawned by multiple weather systems) is a tornado outbreak sequence, occasionally called an extended tornado outbreak.



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2008-04-21 18:11:46 補充：
http://en.wikipedia.org/wiki/Tornado

http://www.nssl.noaa.gov/edu/safety/tornadoguide.html