Assertion: cumulonimbus cloud | /r/HasProperty | embedded within usual nimbostratus
Facets:
value: at an unusually unstable warm front
type: LOCATION
Source sentences:
text: Nimbostratus, unlike cumulonimbus, is not associated with thunderstorms, however at an unusually unstable warm front caused as a result of the advancing warm air being hot, humid and unstable, cumulonimbus clouds may be embedded within the usual nimbostratus.