cell
From Glossary of Meteorology
In radar usage, a local maximum in radar reflectivity that undergoes a life cycle of growth and decay.
The rising portion of the reflectivity maximum is indicative of updraft, and the later descending portion is indicative of a precipitation downdraft. Cells in ordinary convective storms last from 20 to 30 min, but often form longer-lasting multicell convective storms. Cells in supercell storms are more steady and last considerably longer.
See also thunderstorm cell.