the.com/supercell

means A severe, long-lived thunderstorm built around a deep, persistently rotating updraft called a mesocyclone, capable of producing giant hail, damaging winds, and tornadoes.

from A 20th-century compound from meteorology, joining the Latin-derived prefix "super-" (above, beyond) to "cell," the word storm scientists use for a single convective unit — itself from Latin "cella," a small room or chamber. So a supercell is literally a storm-cell raised to the highest power: one enormous, spinning room of weather where the rest are mere closets. The term came into use as radar let forecasters finally see the rotating heart of the worst storms.