Name That Cloud

Clouds: Stratus, Cirrus, Cumulus

By: Eva Reyes, Taylor Griffith, Sandy Bobbitt, Diana Jones

1.Air The air is the invisible gaseous substance surrounding the earth, a

mixture mainly of oxygen and nitrogen.

1. Cloud A visible collection of tiny water droplets or, at colder

temperatures, ice crystals floating in the air above the surface.

Clouds come in many different sizes and shapes. Clouds can form

at ground level, which is fog, at great heights in the atmosphere,

and everywhere in between. Clouds offer important clues to

understanding and forecasting the weather.

2.Precipitation General name for water in any form falling from clouds. This

includes rain, drizzle, hail, snow and sleet. Although, dew, frost

and fog are not considered to be precipitation.

Definitions

What are clouds? A cloud is a large collection of very tiny droplets of water or ice crystals. The droplets are so small and light that they can float in the air.

How are clouds formed? All air contains water, but near the ground it is usually in the form of an invisible gas called water vapor. When warm air rises, it expands and cools. Cool air can't hold as much water vapor as warm air, so some of the vapor condenses onto tiny pieces of dust that are floating in the air and forms a tiny droplet around each dust particle. When billions of these droplets come together they become a visible cloud.

Clouds form when humid air cools enough for water vapor to condense into droplets or ice crystals. The altitude at which this happens depends on the humidity and the rate at which temperature drops with elevation.

Stratus Clouds

Stratus clouds are uniformed layered clouds that are below 6,000 feet.

They are formed in sheets and are usually associated with overcast weather.

Fog or mist is the result of very low stratus clouds.

Stratus clouds are more known for drizzle than for precipitation.

Stratus clouds are formed when a weak upward air current lifts a thin layer of air high enough to start condensation of the excess water vapor if the air temperature falls below the dew point.

Stratus Clouds

• Stratus clouds are uniform grayish clouds that often cover the entire sky

• Four Types of Stratus Clouds

Altostratus Clouds

Altostratus clouds appear in altitudes of 6,000 to 20,000 feet.

They are very thin and uniform, and are gray or blue-gray, creating overcast.

Altostratus clouds are associated with coming rain, and they usually cover most, if not all, of the sky. Altostratus clouds can’t produce heavy precipitation, but they are often the cause of a light drizzle.

Nimbostratus clouds

Nimbostratus clouds form at or below 6,000 feet.

They are dark, low clouds that bring light to heavy prolonged precipitation, such as snow or rain.

Nimbostratus clouds that are broken up are called fractostratus clouds.

Fractostratus Clouds

Low ragged layered cloud often appearing below nimbostratus clouds during rain.

Angry Cloud Video

http://www.youtube.com/watch?v=gdg6WU_aqWE

Cirrus clouds are the most common of the high clouds. They are composed of ice and are thin, wispy clouds

Cirrus clouds are usually white and predict fair to pleasant weather.

By watching the movement of cirrus clouds you can tell from which direction weather is approaching.

When you see cirrus clouds, it usually indicates that a change in the weather will occur within 24 hours

Cirrus Clouds

Cirrus clouds look thin because they are made of ice crystals, not water drops.

They form where it is high enough to be cold and freeze the water drops into ice.

Cirrus Cont.

Types of Cirrus Clouds

Cirrostratus clouds are thin, sheetlike high clouds that often cover the entire sky. Cirrostratus clouds usually come 12-24 hours before a rain or snow storm.

Cirrocumulus clouds appear as small, rounded white puffs that appear in long rows. Cirrocumulus clouds are usually seen in the winter and indicate fair, but cold weather. In tropical regions, they may indicate an approaching hurricane.

Cumulus Clouds

The bright lights of Tucson, Arizona, are more than matched by a flash of lightning far above the city skyline. The sunset scene shows a classic cumulonimbus cloud formation.

Physical Description

Cumulus clouds are puffy clouds that sometimes look like pieces of floating cotton.

The base of each cloud is often flat and may be only 1000 m above the ground.

The tops have rounded towers.

These clouds form below 6000 ft. (extreme cases they can be as high as 39,000).

Cumulus Congestus Clouds

When the top of a cloud looks like cauliflower, it is called a cumulus congestus or towering cumulus.

These clouds grow upward and they can develop into a giant cumulonimbus, which is a thunderstorm cloud.

Cumulonimbus Clouds

These are severe weather clouds and often have the potential to generate heavy rain, strong winds, severe lightening, damaging hail and deadly tornadoes.

http://www.youtube.com/watch?v=exlVSEPEXKc

The Weather of Cumulus Clouds

Typical cumulus clouds are usually associated with fair weather

Congestus cumulus clouds often grow large enough to produce short and strong periods of rain.

Cumulonimbus clouds are likely to bring thunderstorms and tornadoes.

Tornadoes are among Earth's most violent natural acts. About a thousand of them touch down in the United States each year, more than in any other country in the world. Some are wispy and last only seconds, others rampage across the landscape for more than an hour, but few are as destructive as the one that obliterated Manchester.

By definition tornadoes are rotating columns of air that extend from swelling cumulonimbus clouds to the ground. No one fully understands tornado dynamics, but certain ingredients seem essential to the witches' brew from which twisters emerge: warm, humid air near the ground, colder air aloft, and shearing winds that change direction and speed with height. The most destructive and deadly tornadoes form under the bellies of super cells, large long-lived thunderstorms whose winds are already in rotation.

http://science.nationalgeographic.com/science/earth/earths-atmosphere/chasing-tornadoes-earth/#page=2

Tornadoes

http://www.youtube.com/watch?v=006guBgSf14 http://www.youtube.com/watch?v=D1IV6INfqfA

NAME THAT CLOUD

Characteristics: • High Clouds • Thin & Wispy • Fair to pleasant weather

Cirrus

Characteristics: Associated with

overcast weather.

uniform grayish clouds that often cover the entire sky

Lower clouds

Stratus

Characteristics: • puffy clouds that

sometimes look like pieces of floating cotton

• Can produce severe weather