Splitting convective storm
From AMS Glossary
splitting convective storm
The process by which a single convective cell splits into two supercells, one dominated by cyclonic rotation and the other by anticyclonic rotation, their paths then deviating substantially from each other and other nearby convective cells.
Splitting storms require strong environmental vertical wind shear, with unidirectional vertical wind shear promoting the development of mirror-image supercells, and clockwise or counterclockwise hodograph curvature in the lowest few kilometers above ground level promoting the preferred development of a cyclonic or anticyclonic supercell, respectively. The cyclonic supercell is often observed to propagate to the right of the mean wind (in the Northern Hemisphere), while the anticyclonic supercell propagates to the left of the mean wind.