1.
altostratus; mid-level cloud layer
A type of cloud forming a uniform gray or blue-gray sheet at middle altitudes (roughly 2,000–7,000 meters), often indicating approaching rain.
空が高層雲に覆われている。
The sky is covered by altostratus clouds.
高層雲が広がると雨が近いことが多い。
When altostratus spreads, rain is often approaching.
天気予報では午後から高層雲が厚くなり、夕方には雨になると伝えていた。
The weather forecast said the altostratus would thicken from the afternoon and turn to rain by evening.
One of the ten basic cloud types classified by the World Meteorological Organization. Composed of 高層 (high level) and 雲 (cloud). Despite the name containing 高 (high), 高層雲 forms at middle altitudes. The name reflects an older Japanese classification system.
COMMON COLLOCATIONS:
- 高層雲が広がる — altostratus spreads
- 高層雲に覆われる — to be covered by altostratus
- 厚い高層雲 — thick altostratus
RELATED TERMS:
- 巻層雲 — cirrostratus (higher-altitude thin cloud layer)
- 乱層雲 — nimbostratus (rain-bearing cloud layer)
- 積乱雲 — cumulonimbus (thundercloud)
- 雲 — cloud (general term)