Stratus Fractus

Above: Stratus Fractus

Stratus Fractus

Stratus fractus clouds are one of the two species of low-lying clouds called stratus clouds. Along with stratus nebulosus, the other species of stratus clouds, these clouds have a uniform sheet-like appearance and are very thick so when they appear, they conceal the sun since they almost cover the entire sky. These clouds are featureless and look much like a fog or mist except that they are not resting on the ground. These clouds do not usually produce precipitation but when they do so, they only produce a drizzle or fine snow grains in small quantities.

How are stratus fractus clouds formed?

Stratus fractus clouds belong to the cloud types or genera of clouds called stratiform. The name comes from the Latin word strato which means sheet as it is so structured.  These low stratiform clouds are formed in precipitation when a warm air mass traps a colder air mass as it is being pushed up by the front which happens under a main frontal cloud deck. Another way by which non-frontal stratus clouds are formed is when an advection fog, developed when a large air mass is warmed by the sea surface picking up water vapor and cooled as it passes through a cool sea surface forming water droplet, is lifted higher because of the breeze. The lifted advection fog is then transformed to stratus clouds.

Classification of stratus fractus clouds

One of the forms of stratus fractus is fractonimbus that develops in precipitation due to a turbulent air movement. They are dark gray in color and appear in ragged sheets. This form of clouds can only be seen under altostratus, nimbostratus or cumulonimbus clouds which are all precipitation clouds. Eventually, stratus fractus clouds may actually merge with the overlying nimbostratus clouds.
Stratus fractus clouds may also take the form of fractus clouds which are actually accessory clouds since they are cut or sheared from the parent cloud because of strong winds. As such, these cloud fragments have a shredded or jagged appearance resembling small torn cotton candy pieces.

What do stratus fractus clouds look like?

Stratus fractus clouds generally appear during a cloudy day having a dark gray to almost white color as they are made up of water droplets and generally formed in precipitation. They look like ragged sheets which became separated from a large stratus clouds because of the wind. They are layered horizontally unlike cumulus clouds and they have a uniform base. As compared to cumulus fractus clouds, stratus fractus clouds have a darker color, is vertically smaller and its particles are more relatively dispersed.

Where can I see stratus clouds?

  • Stratus fractus clouds are one of the low-level clouds so they can be seen from the surface at about a height of only 2000 meters or 6500 feet in the sky.

 

  • They are usually visible in areas where there are mountains and bodies of water like oceans and seas during a cloudy day and because of their gray color and sheet-like structure, they almost block out the sun in the areas where they appear.

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