A tornado too can occur over a sea:
http://en.wikipedia.org/wiki/Waterspout
A more major difference seems to be this: a tornado typically forms beneath and in contact with a cloud such as a cumulonimbus cloud which is not itself the tornado; a cyclone/hurricane/typhoon typically reaches the upper end of the troposphere (i.e. above clouds) and comes in a much larger scale than a typical tornado's, and the whole aerial area including the clouds constitues the phenomenon of the cyclone.
I think "carbi'e" is fine for both "cyclone" and "tornado". And we probably want a more specific brivla for each. Maybe "balcarbi'e" for "cyclone".