Many have seen it, but not everyone has known what these clouds are called or how they are formed. Lucky enough, Courtney’s Cloud Corner can help explain.
Pileus clouds are similar to lenticular clouds, as they both appear in a lense shape. Although lenticular clouds can be found in the sky over mountain tops or high elevated areas, whereas pileus clouds can be formed over towering clouds. Pileus can form over a mountain but tend to look like it’s hugging the mountain instead of in the sky over the mountain like lenticular. What is needed to form pileus clouds are a strong updraft from lower altitudes that will lift warm moist air to saturation, where it will then cool and condense to form a cloud. Usually the storm clouds, such as cumulonimbus and cumulus clouds, have the structure of lifting. The updraft will lift the air above the growing cloud to produce the pileus cloud above. They are notably short lived, as the towering cloud will continue to grow through the pileus cloud.