Tornado - Wikipedia, the free encyclopedia
Rotation
Tornadoes normally rotate
cyclonically (when viewed from above, this is counterclockwise in the
northern hemisphere and clockwise in the
southern). While large-scale storms always rotate cyclonically due to the
Coriolis effect, thunderstorms and tornadoes are so small that the direct influence of the Coriolis effect is unimportant, as indicated by their large
Rossby numbers. Supercells and tornadoes rotate cyclonically in numerical simulations even when the Coriolis effect is neglected.
[34][35] Low-level
mesocyclones and tornadoes owe their rotation to complex processes within the supercell and ambient environment.
[36]
Approximately 1 percent of tornadoes rotate in an anticyclonic direction in the northern hemisphere. Typically, systems as weak as landspouts and gustnadoes can rotate anticyclonically, and usually only those which form on the anticyclonic shear side of the descending
rear flank downdraft in a cyclonic supercell.
[37] On rare occasions,
anticyclonic tornadoes form in association with the mesoanticyclone of an anticyclonic supercell, in the same manner as the typical cyclonic tornado, or as a companion tornado either as a satellite tornado or associated with anticyclonic eddies within a supercell.
[38]
net als de tornado's of het kolkje in de gootsteen... 
, misschien later, kan denk 150 gram gewichtsverschil opleveren)
