1. Cloud Types
Recognizing and appreciating Nature’s water carriers

2. Convection: How Clouds Form
Upward flowing air currents cause clouds to form
Warm air condenses in higher cool air
Warm air rises

3. Different Heights, Different Clouds

4. High Level: Cirrus Forms only in very dry air
May mean fine weather will continue
If cirrus increases to cover most of the sky, wind and rain may soon follow
Cirrus is made up of falling ice crystals drawn out by the wind into filaments
The longer the filaments, the stronger the wind
Sailors once used cirrus clouds as a "wind warning"

5. High Level: Cirrocumulus
A patch or layer of cloud consisting of tiny individual cloudlets at high level
The cloudlets may make a regular dappled or rippled pattern
Referred to as a "mackerel" sky
May mean unsettled weather is on its way
Like all high-level clouds, cirrocumulus is made of ice crystals

6. Cirrostratus
May cover the sky as a continuous sheet with no features, but it often has a fibrous look
Cloud is so thin it is almost transparent
You can see the sun or moon through it
Forms a halo around sun or moon
Cirrostratus often signals changing weather

7. Medium Level: Nimbostratus
Blanket of grey cloud hiding the sun and any higher cloud
Sheet cloud from which rain or snow is falling
Forms when warm, moist air is lifted steadily over a large area
Thick enough to block out the sun
Base can be quite low: anywhere from 2,000-7,000 ft (600-2,000 m)
Usually the air is stable and there is little turbulence in the cloud

8. Medium Level: Altostratus
From the ground altostratus looks white or slightly blue and watery
May form a continuous sheet, or look as though it is made from soft fibres
Light, with the sun often visible through it
Rain or snow may fall.
Frequently, though not always, covers the whole sky
Clouds of other types may be visible at its edges or beneath it

9. Medium Level: Altocumulus
Small, white, puffy clouds that sometimes slowly drift across the sky
Looks like dozens, of small, loose cotton balls
Forms between 8,000-18,000 ft ( km)
Usually forms in a layer of moist air, where air currents undulate gently
As a layer rises, water vapour condenses, forming the cloud

10. Low Level: Cumulus
Puffy white clouds that drift across the sky on a bright summer day
Small and scattered, they’re a sign of fine weather
Clouds form in columns of rising air above ground that is being heated strongly by the sun
As it rises it cools, and the water vapour condenses onto particles of matter called condensation nuclei

11. Low Level: Stratus
Forms in stable air, which has little or no turbulence
If it forms in air lifting over hills or along a front, it may be followed by rain
Can also form at night when moist air moves over land that is cooling
Base height is normally in the lowest 2,000 ft (600 m) of the atmosphere

12. Low Level: Stratocumulus
Grey, white, or a mixture of both, usually with some darker patches
Can look threatening, but unless it’s very thick usually only drizzle or light rain falls from it
Formed when warm, moist air mixes with drier, cooler air and the mixture is moving beneath warmer, lighter air above
Base is typically at 1,000-7,000 ft (300-2,000 m)