Thunderstorm — single-cell stages

A thunderstorm is a cumulonimbus cloud (Cb) with electrical discharges, strong updrafts, heavy precipitation, and usually hail. A typical single-cell thunderstorm has three stages.

Source: WMO; FAA AC 00-6B Aviation Weather; ICAO Doc 9817; AMS Glossary.

Prerequisites

The prerequisite for any kind of thunderstorm development is high-reaching, moist and unstable layering of air:

Moisture (vapour for condensation).
Unstable layering (convection).
Trigger (thermal, orographic, frontal).
High vertical reach to tropopause for anvil.

Three single-cell stages

1. Cumulus stage (towering / building)

Duration: 15-30 min.
Updrafts only (5-25 m/s).
Cb grows vertically.
No surface precipitation.

2. Mature stage

Duration: 15-30 min.
Updrafts AND downdrafts coexist.
Precipitation begins at the ground.
Maximum danger: hail, severe turbulence, lightning, wind shear.
Anvil forms at the tropopause.

3. Dissipating stage

Duration: 30 min - 2 h.
Downdrafts only.
Precipitation weakens.
Cloud dissipates, leaving the anvil.

Growth heights

Cu Cong → TCu → Cb transition.
Typical Cb height Central Europe: 8-13 km (to tropopause).
Tropics: up to 18 km.

Multi-cell and supercell

Multi-cell: several cells at different stages, lifespan hours.
Supercell: rotating mesocyclone, very strong, lifespan up to 6 h, tornado potential.
Squall line: line of thunderstorms, often at cold fronts.

Aviation Weather*; ICAO Doc 9817; AMS Glossary; FAA-H-8083-25B PHAK Ch. 12.*