|WHEN CLOUDS LOOK LIKE BLACK SMOKE
METEOROLOGIST JEFF HABY
WEATHER FOLKLORE: "When clouds look like black smoke a wise man will put on his cloak"
APPLICABILITY: Warm season maritime tropical airmass.
ANALYSIS AND INTERPRETATION: The clouds that look like black smoke refer to cumulus congestus clouds. When
the sun shines directly onto them they are bright white. The cumulus congestus that are in a "shadowed" area
look very dark. The shadow is cast from neighboring cumulus clouds.
When cumulus congestus are developing there is a sharp boundary between the cloud and the surrounding air. The clouds
will take on a cauliflower appearance. Cumulus clouds have a high density of water and
water vapor within them. They
are able to darken the sky due to the ability to prevent sunlight from penetrating.
The cloak refers to raingear. Storms are in their developing stage when the cumulus clouds first start
penetrating deep into the troposphere. Shortly after the storm will reach the mature stage and
heavy rain will fall.