…and weather prediction

Clouds, snow, and rain are all made of up of some form of water. Cloud = tiny water droplets and/or

ice crystalsRain = liquid waterSnowflake = many ice crystals

Common sources of moisture for the US are warm moist air massesmT, mP, mE

How do clouds form? Think about the cloud lab.1. Heating of the Earth’s surface2. Heated air rises and expands3. It begins to cool4. Water vapor condenses if…5. …there are aerosols in the air for vapor to

condense on

The presence of clouds tells a change is coming

Understanding cloud types helps us predict the changes

British pharmacist and chemist Luke Howard (1803)

Meteorologists have used the system ever since, with minor modifications

Clouds are given Latin names corresponding to

- their appearance - their altitude - whether they create precipitation

1. Height a) Low Strato- (layer)b) Mid Alto- (high, tall)c) High Cirro- (curl – thin high)

2. Shape a) Fluffy cumulus (heap)b) Layered stratus (layered)c) Wispy cirrus (curl)

3. Produce precipitation nimbus

Strato-

Low layered clouds Form when air rises

slowly Can look like fog that

doesn’t touch the ground Can produce light drizzleWhen stratus breaks up

and dissipates blue sky is often revealed

Low and fluffy Small clumps

(about the size of a fist) Can produce drizzle

Low clouds with precipitation

Produce continuous rain or snow

Usually associated with a warm front

Fluffy, fair-weather clouds Develop vertically

when air rises rapidly due to daily convection; it appears in the morning, grows, and then more or less dissolves again toward evening

Can combine into a cumulonimbus cloud

Fluffy with precipitationHeavy dense cloud taking the shape of a

mountain or huge tower The upper portion is usually high and flat

Produce thunderstorms, hail and tornadoes

Alto-

Mid-level layered cloud Sheets or layers of

clouds that may totally or partially cover the sky

They are thin enough to see the sun, but do not allow shadows on the ground to form

At times, they may produce rain associated with a warm front

Mid-level fluffy clouds The most common mid cloud, often appears with

other cloud types Multiple layers may appear at different levels

concurrently Can create a corona passing in front of the sun or

moon (colored rings with red outside and blue inside)

Often form in front of a cold front and result in thunderstorms

Cirro-

High-level curled Wispy delicate white patches

or narrow bands Composed of ice crystals Before sunrise and after sunset, cirrus is often colored

bright yellow or red and are lit up long before other clouds and fade out much later

High, layered Transparent, whitish veil clouds Usually covers the whole sky Distinguished from altostratus by the halo phenomena

produced by the sun or the moon

High fluffyUncommon cloudDegraded state of cirrus and cirrostratus Thin, white patch, sheet, or layered of

clouds without shading Composed of very small

elements in the form of more or less regularly arranged grains or ripples

Top of Troposphere = 7.5 miles

6 miles (jets)

4 miles (21,100 ft.)

1.25 miles (6,500 ft.)

Mammatus

Lenticular Altocumulus

lenticularis