Classic Supercells

Supercells form when environmental shear and thermal instability
are ultimately matched.

A classic supercell is an isolated storm that possesses the 
classic "Hook Echo" or BWER (Boundary weak echo region). Strong
reflectivities are located in the upper level. Beneath the
overhang, the low-level echo frequently shows an inflow notch
with a pendant or hook at the back side.

These storms are frequent producers of tornadoes, large hail,
and strong winds.