1.
cumulonimbus cloud; thunderhead
A massive, towering cloud formation that develops vertically and produces heavy rain, thunder, lightning, and sometimes hail or tornadoes. The formal meteorological term.
積乱雲が発生している。
A cumulonimbus cloud is forming.
夏は積乱雲が発達しやすく、夕立の原因になる。
Cumulonimbus clouds tend to develop easily in summer, causing sudden evening showers.
気象庁は積乱雲の急速な発達に注意するよう呼びかけた。
The Japan Meteorological Agency called for caution regarding the rapid development of cumulonimbus clouds.
A compound of 積 (accumulate) + 乱 (turbulent) + 雲 (cloud). This is the formal meteorological term used in weather forecasts and science education. In everyday Japanese, the same cloud type is often called 入道雲 (literally "priest cloud," referring to the bald-headed shape).
COMMON COLLOCATIONS:
- 積乱雲が発達する: cumulonimbus clouds develop
- 積乱雲が発生する: cumulonimbus clouds form
- 積乱雲に注意: watch out for cumulonimbus
- 発達した積乱雲: well-developed cumulonimbus
RELATED TERMS:
- 入道雲: everyday name for towering cumulonimbus (summer cloud)
- 雷雲: thundercloud (general term)
- 積雲: cumulus cloud (the smaller, fluffy type)
- 乱層雲: nimbostratus (rain-producing layer cloud)