The National Severe Storms Laboratory (NSSL) (www.nssl.noaa.gov)
and The Storm Prediction Center (SPC) (www.spc.noaa.gov),
are the leading US government authorities on severe weather and tornadoes.
Their websites provide useful information on all types of severe weather.
The scientists and meteorologists at the NSSL and
SPC have put together a comprehensive FAQ list for tornadoes.
See http://www.nssl.noaa.gov/researchitems/tornadoes.shtml
and http://www.spc.noaa.gov/faq/tornado/
