Usually they are found in the middle layer of the troposphere (the lowest region of the atmosphere), lower than the cirrocumulus clouds but higher than their cumulus and stratocumulus.
The term ‘mackerel sky’ is also commonly associated with altocumulus; these clouds display a pattern resembling fish scales. Of the ten types of cloud, autocumulus is the most diverse and dynamic when it comes to appearance.
Altocumulus Cloud Characteristics
These clouds come in a wide range of shapes and sizes.
They can include cloud heaps that look like a towering castle, can sometimes look like a lock of wool, they can take up the entire sky on certain occasions and finally they can create horizontal tube looking structured clouds.
Altocumulus clouds are known for their weird ability to create UFO-shaped clouds and are responsible for a lot of the fallstreak hole sightings. You may be lucky enough to on a rare occasion create a cloud with a wavy, chaotic appearance.
Altocumulus Cloud Facts
Altocumulus clouds sit at the middle of the troposphere; they typically sit in the sky between 7,000-23,000 feet. They appear at a large range due to the range of forms they can take that will differ in height.
The name altocumulus derives from the latin term alto- meaning high and cumulo- meaning heap. The clouds take on a wide range of color; they can either be white on a bright sunny day to a fairly dark gray.
When there are altocumulus clouds in the sky they will cover a wide range with the sky either being mostly cloudy or only a few being in the sky making it mostly sunny.
The cloud forms at a very common frequency meaning on cloudy days you will most likely see a form of altocumulus clouds.
Altocumulus Cloud Species
There are five species associated with altocumulus: castellanus, floccus, lenticularis, stratiformis and volutus.
Castellanus clouds look like rising cumuliform towers with a connected base. This species of cloud is uncommon but can be expected to be seen on days when the atmosphere is more unstable.
These clouds are the most popular with storm chasers because they will point towards unstable air which usually means a thunderstorm will develop in the area.
Floccus clouds form in ragged groups and heaped groups of clouds. These clouds are not connected at a base but can exist in close proximity to each other.
They are easy to see with the naked eye and are more common. Evaporating rain stripes can also usually be spotted in floccus cloud formations; these formations can also resemble flying jellyfish.
Lenticular clouds can easily be different from other cloud species due to their distinctive UFO appearance with smooth edges.
These clouds are formed when an obstruction is in the way, these obstructions are typically mountains, these obstructions will get in the way of the typical airflow at that level of the atmosphere.
When the airflow is obstructed the air will rise and then fall in a pattern resembling a wave. As this air rises it meets a layer of moist air, the air then condenses and forms a cloud.
Due to the lenticular clouds being an indication of windy conditions, airline pilots will know to avoid the areas where the clouds form.
Stratiformis clouds extend across the entire skyline they allow for many species of cloud and cloud features to exist for example it allows for fallstreak holes to occur and are almost always seen in stratiformis cloud formations.
Another example is the virga or strips of precipitation that evaporate before reaching the ground can usually be picked out in the stratiform is cloud species.
Finally, we have the volutus clouds. These clouds resemble horizontal tubes. Well defined examples of roll clouds can catch a lot of attention especially on social media for their ominous and bizarre appearance.
Volutes cloud formations are very uncommon but as a species they are more often found as stratocumulus clouds.
When clouds are classified as a species of volutes usually it is taken note of how the clouds standalone and do not usually have any associated features or varieties.
They are easy to spot simply due to their uniqueness and create a lot of buzz among cloud spotters whenever one is in the area due to them being an extraordinary phenomena.
Final Thoughts
So there you have it all you need to know about altocumulus clouds and their different species, characteristics and what makes them truly unique amongst a sky filled with many different types of cloud.
Hi, my name is Andrew Capper and I have been a meteorologist for almost 30 years now. My line of work specializes in the scientific principles used to explain and understand the earth’s atmosphere and how that affects everyday life.
I created this website to share my knowledge and help others stay safe during extreme weather events.
I’ll be looking at weather forecasting, clouds, tornadoes, hurricanes, and much more - so, if you’ve ever been fascinated by the weather like I have been since I was a young boy, this is the site for you. Enjoy!
