The initial streamer of a lightning discharge; an intermittently advancing column of high ion-density which establishes the channel for subsequent return streamers and dart leaders. The peculiar characteristic of this type of leader is its step-wise growth at intervals of about fifty to one hundred microseconds. The velocity of growth during the br [..]

ir lightning.

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Cumulonimbus cloud, characterized by strong vertical development in the form of mountains or huge towers topped at least partially by a smooth,flat, often fibrous anvil. Also known colloquially as a "thunderhead." See Fig. 9 Cumulonimbus.

Convection in the form of a single updraft, downdraft,or updraft/downdraft couplet, typically seen as a vertical dome or tower as in a cumulus or towering cumulus cloud. A typical thunderstorm consists of severalcells (see multi-cellular thunderstorm). The term "cell" also is used to describe the radar echo returned by an individual showe [..]

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Small strips of metal foil, usually dropped in large quantities from aircraft or balloons. Chaff typically produces a radar echo which closely resembles precipitation. Chaff drops once were conducted by the military in order to confuse enemy radar, but now are conducted mainly for radar testing and calibrarion purposes.