  The results are presented of an analysis, with the help of the method of
multilevel dynamical contrasting of the images, of available databases of the
images of tornado. This analysis extends some preliminary results on
identification of skeletal structures in tornadoes (Phys. Lett. A 306 (2002)
175) and enables us to apply to the case of tornado our former hypothesis for
the probable role of nanotubular dust in the origin and stability/longevity of
filamentary structures of a skeletal form in electric discharges. A hypothesis
for the contribution of nanotubular dust to initiation of tornadoes is
suggested, in which a key role is delivered to ability of the hypothetical
skeleton inside the thundercloud to provide fast long-range transport of
electricity. Thus, initiation of tornado is suggested to be an electrostatic
instability caused exclusively by the presence and special structuring of a
nanodust.
