Often associated with thunderstorms or cold fronts, these clouds are usually low and tube shaped.
Also associated with cold fronts and thunderstorms, shelf clouds differ from roll clouds in that they are usually attached to the parent cloud directly above.
These slim, horizontal spirals tend to dissipate quickly after their initial formation making observation difficult. These wave-like clouds are caused by a difference in velocity across the interface of two fluids. In layman’s terms, you’re most likely to see these clouds when wind blows above the water. They are also referred to as Kelvin-Helmholtz Billow clouds.
These rare pouch-like clouds usually form after the thunderstorm has passed. Contrary to “common knowledge,” they do not indicate an imminent tornado (although they do look ominous).
Sometimes referred to as “mother of pearl” clouds, these can be found at altitudes of up to 20 miles. Usually seen in polar regions near the poles, they are known for their iridescent colors.