Flying 1: Clouds, Ceiling, Visibility, and Fog Flashcards
What are the two main types of clouds?
normal and special
What are the two types of normal clouds?
cumuliform and stratiform
What are cumuliform (convective) clouds?
puffy and associated with updrafts
Cumuliform (convective) clouds:
When do they form?
when humid air rises through cooler air
- occurs when air at ground is colder than surface (ie. air above the ocean is colder than the ocean surface)
- occurs behind cold fronts
- clear days when sunshine warms the earth more than air
- cold air blows over warm air or warm body of air
When does humid air rise through cooler air?
- occurs when air at ground is colder than surface (ie. air above the ocean is colder than the ocean surface)
- occurs behind cold fronts
- clear days when sunshine warms the earth more than air
- cold air blows over warm air or warm body of air
Cumuliform (convective) clouds:
What drives the strong updrafts?
buoyancy
Cumuliform (convective) clouds:
What are the 4 classifications and what are they classified by?
classified by vertical depth
Cumulus humilis (small): can have turbulence from updraft
Cumulus mediocris (medium): can have turbulence from updraft
Cumulus congestus (large): poses hazard, thunderstorms and violent updrafts
Cumulonimbus (thunderstorm): poses hazard, thunderstorms and violent updrafts
What are stratiform (layer) clouds?
flatter like sheets or blanket, and can extend hundreds of kilometers
Stratiform (layer) clouds:
How must pilots fly?
need to rely on IFR
Stratiform (layer) clouds:
What may form edges if cloud is below freezing?
ice
Stratiform (layer) clouds:
When do they form?
where there are layers in the atmosphere with different relative temperatures
- associated with warm fronts
- high clouds approach first, followed by lower clouds
Stratiform (layer) clouds:
How are they classified?
classified by altitude: they get thicker and less holes with decreasing altitude
high
middle
low
Stratiform (layer) clouds:
What are the high clouds?
Cirrus: thin wispy, ice and crystals
Cirrostratus: thin but with more coverage: ice, halo
Cirrocumulus: mix, a bit lumpier
Stratiform (layer) clouds:
What are the middle clouds?
Altostratus: mix, corona
Altocumulus: lumpier, mix
Stratiform (layer) clouds:
What are the low clouds?
Stratus: well defined cloud base, no precipitation
Nimbostratus: blurry cloud base, some type of precipitation
What are castellanus clouds?
- description
- appearance
- info
unstable airloft
appearance: small castle turrets
info:
- atmosphere is unstable
- thunderstorms possible later in the day
What are billow clouds?
- description
- appearance
- info
unstable airloft
appearance: waves in a cloud
info:
- indicates wind shear and creates CAT (clear-air turbulence)
- related to Kevin-Helmholtz waves
What are lenticular clouds?
- description
- appearance
- info
mountain waves, strong winds across mountains
appearance: “bubble shape,” little UFOs
info:
- wind oscillations
- may indicate mountain wind turbulence
What are rotor clouds?
- description
- appearance
- info
strong winds across mountains
appearance: ragged looking under mountain
info:
- ragged looking cloud that forms at low altitude under crests of mountain waves
- BIG HAZARD
What are banner clouds?
- description
- appearance
- info
strong winders across mountains
appearance: like a banner blowing off the mountain
info:
- indicates strong turbulence
- usually only on an isolated peak
What are pyrocumulus clouds?
- description
- appearance
- info
extra heat
appearance: located over a big fire or volcano
info: heat and moisture released is so strong it can make a thunderstorm
What are pileus clouds?
- description
- appearance
- info
updrafts
appearance: little hat on cumulus clouds
info: form over fast-growing cumulus clouds
What are fractus (scud) clouds?
- description
- appearance
- info
low altitude turbulence
appearance: ragged, low
info:
- turbulent humid air near ground
- indicates high humidity and strong winds
What are fumulus clouds?
- description
- appearance
- info
man-made
appearance: above smoke stacks
info: water droplets condense over cooling towers
