Besiege the Stratocumulus Castellanus!

Štěpán Šubík

The second most common species of Stratocumulus is Stratocumulus castellanus (Sc cas). Its name means castellan, the governor of a castle, and it has a connection to its appearance.

Photo: Merikanto;
link: https://commons.wikimedia.org/wiki/File:Stratocumulus_castellanus_1.JPG;
licence: cc;
desc: Stratocumulus castellanus.;

Stratocumulus castellanus looks like a majestic walled castle with turrets soaring to the skies. The turrets have a common horizontal base, they seem to be arranged in lines and are sometimes taller than they are wide. You can recognize this species especially seeing it from the side.

The specific shape is generated by a layer of moist air that cools down by emitting radiation. The water condensates and the base of our castle is created as a flat cloud. Then there must be an unstable air mass to make the air rise in terms of thermal convection. And if the convection is stronger and weaker somehow regularly in our flat cloud, the turrets will be created. If the convection is really strong, the Cumulus congestus or even Cumulonimbus will be created.

Stratocumulus castellanus can cause a wide, but not intensive precipitation. And when it does, it slowly loses its magnificent shape.

Have you ever seen the castellanus of the sky? Send us your photo!

photo: Juan de Vojníkov;
link: https://commons.wikimedia.org/wiki/Stratocumulus#/media/File:Clouds_aroun_Mile%C5%A1ovka_(006).JPG;
licence: cc;
desc: Stratocumulus castellanus and Altocumulus stratiformis translucidus perlucidus cloud taken from Milešovka, Czech Republic.;

photo: Merikanto;
link: https://commons.wikimedia.org/wiki/File:Stratocumulus_castellanus_2.jpg;
licence: cc;
desc: Stratocumulus castellanus low level cloud.;

10 February 2019