altocumulus stratiformis translucidus perlucidus clouds at summer morning. the term `mackerel sky` is common to altocumulus clouds

abstract aerial air altocumulus altostratus amazing atmosphere background beautiful beauty blue bright cirrocumulus climate cloud clouds cloudscape cloudy color cover cumulostratus cumulus dense fluffy formation gap heaven high light mackerel natural nature outdoor pattern perlucidus scenic sheep sky stratiformis stratocumulus summer sunlight sunny sunrise texture translucidus view weather white