Be able to…

•Define a cloud

•Explain how clouds form

•Identify the ten main cloud types

*

*Q: What did the rain cloud

where under his rain coat?

*A: Thunder wear!

Clouds are droplets of water, or

tiny crystals of ice, or a mixture of

both:

*Visible indication of what is

going on in the atmosphere

*Adiabatic cooling is the most

important cloud forming

process

*Air rises and cools from

*Takes about a million cloud droplets to form a single raindrop

Forms when air cools to the dew point.

*Clouds are water vapor that

condenses and collects around

aerosols. (particles of dust, smoke,

salt particles, pollen, burning from

forest fires, automobiles, or ice

crystals)

*The flat cloud base shows where the

water vapor began to condense.

This height is called the

condensation level (CL or LCL)

4 main precipitation types:

*Rain

*Snow

*Sleet

*Glaze or freezing rain

*Driest place on Earth – Arica,

Chile receives .03 inches of

rainfall per year.

All main clouds are classified

on the basis of two criteria

*Form (puffy or flat)

*Height (low, middle, high)

Horizontal air movement –

stable air

*clouds form in layers

*Stratiform clouds

Vertical air movement –

clouds grow more upward

*Unstable air

*Cumuliform clouds

Clouds contain:

*Water droplets when the air is

above freezing

* Ice crystals and supercooled

water when air is below freezing

Virga – Latin for streak

*Rain frequently evaporating

before reaching the ground

*Or snow sublimating.

Be able to…

•Define a cloud

•Explain how clouds form

•Identify the ten main cloud types