noun
cirrocumulus cloud; mackerel sky
A pattern of small, rippled clouds resembling fish scales; often associated with changing weather. Synonymous with うろこ雲 (scaly cloud).
See also: うろこ雲
秋の空に鰯雲が広がっている。
Cirrocumulus clouds are spreading across the autumn sky.
鰯雲が出ると天気が下り坂になることが多
When mackerel sky appears, the weather often turns bad.
Synonym; both refer to the same cloud pattern. うろこ雲 uses 'scale' imagery, while 鰯雲 uses 'sardine' imagery.
Compound of 鰯 (いわし, 'sardine') + 雲 (くも, 'cloud'), from the resemblance of the cloud pattern to a school of sardines.