Clouds Flashcards
(15 cards)
What are the four families of clouds?
Cirriform
Cumuliform
Stratiform
Nimbus
Cirriform Clouds
Clouds which are fibrous or seem to have several smaller fibers or pieces of cloud.
Cumuliform Clouds
Clouds which seem to be heaped or stacked/towered vertically
Stratiform Clouds
Layered clouds. Steady precipitation preceding a front is an indication of stratus clouds with little or no turbulence.
Nimbus Clouds
Clouds with rain. The suffix “nimbus” is used to mean “rain cloud”
What are the four families of clouds based on height?
High Clouds
20,000’ and above
Mid Level Clouds
6,500’ to 20,000’
Low Clouds
Between the surface and 6,500’
Vertically Developing Clouds
Cloud bases range from 1000’ to 10,000’ AGL
Stratus Clouds
Layer or uniform cloud
Formed when warm, moist air flows upslope over terrain or up and over a cold air mass.
Mostly horizontal movement of air and no vertical development.
Cumulus Clouds
Associated with unstable air.
Aircraft entering a cumulus cloud can expect turbulence and icing.
Aircraft flying below a cumulus cloud can also expect turbulence and strong downdrafts or wind shear.
Stratocumulus Clouds
Layer of small lumps and heaps
Combination of stacked cumulus and layered stratus
Form when stable air is lifted. Can also be formed when a stratus or cumulus cloud is broken up by an air mass.
Nimbostratus Clouds
Thick dense layer of stratus clouds with steady rain or snow.
VFR aircraft should avoid flying below a nimbostratus since the clouds are expected to contain precipitation such as snow or hail which will reduce visibility significantly.
A pilot may also experience turbulence and downdrafts under a nimbostratus as well as possible icing in cold conditions.
Cumulonimbus Clouds
Clouds range from 1,000 to 10,000’
Cumulonimbus Momm
Thunderstorm clouds that are associated with a particularly violent and dangerous storm that may include tornadoes.
Altocumulus Standing Lenticular
Sometimes called lenticular or mountain waves.
Almond or lens shaped crests of standing mountain waves.
These clouds come with very strong turbulence.
They appear to be stationary, but this can be deceiving, as they can contain winds up to 50 knots.
Mountain wave turbulence can be expected above mountainous terrain and even 100 miles downwind of a mountain when winds of 40 knots or more blow across a mountain
Altocumulus Castellanus
A group of small, cumuliform clouds that all have the same base level indicating possible growth of larger, mid-level clouds in an unstable atmosphere.
