The best replacement for tornado is cyclone.

The best alternatives to tornado are rated as following:
★★★★★  cyclone
★★★★  hurricane
★★★  twister
★★  train
★  twisted
★  flask
★  earthquake
★  node.js
★  typhoon
★  hurricane worse
★  bikini bottom
★  django
★  funnel cloud
★  turbonator
★  peyote
  azureus
  volcano
  thunderstorm
  hurricane stronger
  screwdriver
  gevent
  hounds of balthazar
  hurricane which is worse
  hurricane difference
  whirlwind
  funland
  whirlpool
  train video
  hurricane wind speed
  house minecraft
  mr perfect
  510
  tank
  truck
  bit comet
  waterspout
  train youtube
  cyclones
  hurricane more dangerous
  semi
  vision
  rainbow
  gunicorn

Your alternative for tornado is not listed? Suggest!
Speaking about tornado, one probably shouldn't forget about thunderstorm.

Other search terms related to tornado and their ratings are:
★★★★★ thunderstorm
★★ lightning pictures
★★ hail
★★ django
You have in mind a companion for tornado and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of tornado in all years. Click on graph for more.
tornado
cyclone
hurricane