Clouds of the Day - Waning Cumulus - Tuesday, September 12, 2023

We are headed to fall and the transition to autumn weather. That means cooler weather and a change in what cloud types visit our skies. Instead of Cumulus type clouds we begin to see Stratus cloud types. For the moment we are getting the last looks at the puffy clouds of summer. As the Cumulus wane from view they do not disappear suddenly. During the fall months towering thunderstorms (Cumulonimbus) become shorter with weaker updrafts. The threat of severe weather lessens with each passing week as updrafts weaken. The photos below show how clouds reveal the change.

The two photos below are of the same cloud taken a few minutes apart. The left photo shows a Cumulus congestus in the background. It is taller than the Cumulus cloud in the foreground. The cloud in the background has a hard top with many protuberances suggesting the presence of active updrafts. In the right photo the cloud in the background has a softer top with more ragged softer edges which is a sure sign of weakening updrafts. As the weeks pass we will see fewer cumulus type clouds as air masses become more stable. Soon about all we will see are the leaden clouds of stable winter air masses. Those clouds have weaker but broader rising motion that create horizon to horizon flat layered clouds.

Photo Copyright by Craig Johnson

Photo copyright by Craig Johnson