The problem of plume-forming meteoroid impacts into the Earth's atmosphere
is investigated with the use of a simplified analytical model and detailed
numerical simulations. The process of plume formation is found to depend st
rongly on the meteoroid size due to development of Kelvin-Helmholtz instabi
lities at the entry column boundary. As a result, the height of plume risin
g proves to be considerably less than that obtained using simplified model
or numerical simulations with low spatial resolution. It is shown that mete
oroids several meters or less in size do not create ballistic plumes at all
. The results of general consideration are applied to the Sumava bolide (on
e of the brightest detected by the European Fireball Network). The debris c
loud created by this impact rises to an altitude of about 190 km.