LENTICULAR CLOUDS ~~ NATURAL PHENOMENON

A lenticular cloud is a lens-shaped cloud that normally develops on the downwind side of a mountain or mountain range. This occurs when stable, moist air flows over a mountain, creating a series of oscillating waves. If the temperature at the crest of the wave equals the dew point temperature, condensation occurs in a lens formation. As the air falls down the trough of the wave, where the temperature and dew point temperature are not equal, evaporation occurs. Thus, a wave cloud, or a series of lenticular clouds, is capable of forming. These are often mistaken for UFOs because of the saucer-like shape. They can separate into altocumulus standing lenticular, stratocumulus standing lenticular, and cirrocumulus standing lenticular clouds.

Appearance

Lenticular clouds have been mistaken for UFOs, particularly in the shape of a "flying saucer", because these clouds have a characteristic lens appearance and smooth saucer-like shape; also, because lenticular clouds generally do not form over low-lying or flat terrain, many people may have never seen one before and don't know that they can exist. Bright colours (called iridescence) are sometimes seen along the edge of lenticular clouds.

How does Lenticular Cloud Form?

As air travels along the surface of the Earth, obstructions are often encountered. These include both natural features of the Earth, such as mountains or hills, and man-made structures, such as buildings and other structures. These disrupt the flow of air into "eddies", or areas of turbulence influenced by these obstructions.

When moist, stable air flows over a larger eddie, like those caused by mountains, a series of large-scale standing waves form on the leeward side of the mountain. If the temperature at the crest of the wave drops below the local dew point, moisture in the air may condense to form lenticular clouds. Under certain conditions, long strings of lenticular clouds can form near the crest of each successive wave, creating a formation known as a "wave cloud." These wave systems can produce large updrafts, occasionally enough for water vapour to condense and produce precipitation.

Where do Lenticular Cloud Form?

Lenticular clouds form in high altitudes, which is why you may have seen these types of clouds if you live by mountains or you visited

There a frequent occurrence in the Rocky Mountains and places like Mount Rainier Washington. This can happen as a result of wind shear created by a front.

Are Lenticular Cloud Dangerous?

For most of us lenticular clouds are not dangerous. However pilots do tend to avoid flying near these flying saucers due to the turbulence to the airplane systems

Pilots can easily locate the rising air mass based on the orientation of the clouds making the rough air very easy to spot and thus avoid it.

Flight

Pilots of powered aircraft tend to avoid flying near lenticular clouds because of the turbulence of the rotor systems that accompany them, but glider pilots actively seek them out. The precise location of the rising air mass is fairly easy to predict from the orientation of the clouds. "Wave lift" of this kind is often very smooth and strong, and enables gliders to soar to remarkable altitudes and to great distances. As of 2016 the gliding world records for both distance (over 3,000 km; 1,864 mi) and absolute altitude (15,460 m; 50,721 ft) were set using such lift.