beautiful dramatic cloud scape with greyish-white altocumulus clouds and silhouettes of flying swallows in a summer morning

air altocumulus atmosphere background beautiful beauty birds blue clear cloud clouds cloudscape cloudy color cumulonimbus cumulus dark day dramatic floating fluffy flying gray grayish grey high level light masses meteorology mid nature rain rounded scape season silhouettes sky stratocumulus stratosphere summer sunlight swallows tranquil weather white wind