<P> In North America , supercells usually show up on Doppler radar as starting at a point or hook shape on the southwestern side , fanning out to the northeast . The heaviest precipitation is usually on the southwest side , ending abruptly short of the rain - free updraft base or main updraft ( not visible to radar ) . The rear flank downdraft , or RFD , carries precipitation counterclockwise around the north and northwest side of the updraft base , producing a `` hook echo '' that indicates the presence of a mesocyclone . </P>
<P> In North America , supercells usually show up on Doppler radar as starting at a point or hook shape on the southwestern side , fanning out to the northeast . The heaviest precipitation is usually on the southwest side , ending abruptly short of the rain - free updraft base or main updraft ( not visible to radar ) . The rear flank downdraft , or RFD , carries precipitation counterclockwise around the north and northwest side of the updraft base , producing a `` hook echo '' that indicates the presence of a mesocyclone . </P>
where does a tornado form relative to the primary features of a supercell thunderstorm
where does a tornado form relative to the primary features of a supercell thunderstorm
southwestern side
southwestern side