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Connection between hurricanes and tornadoes

  1. Sep 13, 2004 #1
    Is a tornado a small version of a hurricane or do they
    have vastly different physics?
    Could lots of tornadoes come together to form a hurricane?
  2. jcsd
  3. Sep 13, 2004 #2


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    Staff: Mentor

    I wouldn't say they have "vastly different physics," but they are very different and pretty well unrelated weather phenomena. Tornadoes are formed by single thunderclouds with updrafts (from hot ground) so strong that the air starts spinning as it rises. They are localized, self-contained, short-lived, and thousands of times smaller than hurricanes. Hurricanes are entire weather systems, fueled by warm ocean water. While a tornado is a small piece of a piece storm, a hurrican is a storm. Tornados contain winds roughly twice as fast as in a hurricane. They can't group together into a hurricane.
  4. Sep 13, 2004 #3
    Do tornadoes rotate counter-clockwise like hurricanes in the northern hemisphere? I'm leaning towards a "yes", but am unsure where Coriolis' limit of influence stands. I suspect a small lab tornadoe could be in either direction. Any thoughts on this anyone?
  5. Sep 13, 2004 #4
    hurricanes spaun tornadoes in the NE sector
    frances had about a 100 twisters even after it was down from
    hurricane force winds to a depression

    but the twisters can't form into a cane

    both spin the same way
  6. Sep 14, 2004 #5
    What happens if two tornadoes merge?
    Does the wind speed get greater,pressure lower etc?
  7. Sep 14, 2004 #6


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    Science Advisor

    Although the Coriolis effect does not have any direct influence over a phenomenon as small as a tornado (or at least, none wirth noting), there is, nonetheless, a strong causal link. Tornadoes are spawned by thunderstorms (including hurricanes), and thunderstorms are large enough to be influenced by the Coriolis effect. A hurricane in the northern hemisphere always spin counterclockwise, and will always spawn counterclockwise-spinning tornadoes. Most thunderstorms in the northern hemisphere have some counterclockwise rotation as well, and give birth to tornadoes with likewise spin. This accounts for about 99% of all tornadoes in the northern hemisphere.

    However, on rare occasion a thunderstorm can form with a clockwise spin in the northern hemisphere. Such a storm will spin off clockwise-spinning tornadoes.
  8. Sep 15, 2004 #7
    Thanks, LURCH.

    Sorry for hijacking your thread Rothiemurchus. As for your last question, I would suspect that yes, but I'm not sure.
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