Assertion: cumulonimbus cloud | /r/HasProperty | precursor
Facets:
value: to cumulonimbus clouds
type: LOCATION
value: along a cold front
type: LOCATION
Source sentences:
text: The puffy-looking cumulus clouds often don't produce any precipitation and don't even cover the sky, but they are precursors to cumulonimbus clouds, and along a cold front can easily grow into shower-producing clouds.