supercells

A supercell is a type of thunderstorm distinguished by a single, dominant, rotating updraft called a mesocyclone. The rotation arises from strong vertical wind shear in the surrounding environment, which tilts and stretches vorticity into the storm's updraft and can allow the rotation to persist for extended periods, often several hours.

Structurally, a supercell maintains a deep, persistent updraft that organizes the storm’s precipitation and wind field. Inflow of warm, humid air at lower levels feeds the updraft, while downdrafts and hail formation develop as the storm matures. The rotating updraft can be detected on Doppler radar as a mesocyclone, and mature stages may exhibit a diagnostic hook echo and, in some cases, visible features such as a wall cloud or funnel.

Supercells are commonly classified into Classic, Low-Precipitation (LP), and High-Precipitation (HP) types, reflecting differing rain distributions and visibility. LP supercells tend to have strong updrafts with limited rainfall near the core, HP supercells produce heavy precipitation around the storm, and Classic fall in between.

Environment and hazards: supercells require substantial atmospheric instability (often indicated by high CAPE) combined with persistent deep-layer wind shear. They are capable of producing severe weather, including large hail, damaging straight-line winds, and tornadoes. Not all supercells produce tornadoes, but they are a major focus of severe-weather forecasting and warning.

Geographically, they are most frequent in regions with favorable shear, notably parts of the United States, but occur worldwide under suitable conditions.