Precipitation

PrecipitationPrecipitation

Another process brought to you by Another process brought to you by the water cyclethe water cycle

The Five Types of The Five Types of PrecipitationPrecipitation

RainRainFreezing RainFreezing RainSleetSleetSnowSnowHailHail

RainRain

Hits the ground as liquid water.Hits the ground as liquid water.

Can start as liquid water or ice. Ice melts Can start as liquid water or ice. Ice melts as it falls, turning into rain.as it falls, turning into rain.

What shape is a raindrop?What shape is a raindrop?

Rain is measured with a rain gaugeRain is measured with a rain gauge

The shape of a rain dropThe shape of a rain drop

RainRain

SnowSnow Snow is formed when water vapor turns Snow is formed when water vapor turns

directly into ice without ever passing directly into ice without ever passing through a liquid state. This happens as through a liquid state. This happens as water condenses around an ice crystal. water condenses around an ice crystal.

Snow can be ice pellets or snow flakes. As Snow can be ice pellets or snow flakes. As snow falls to the ground, it often melts on snow falls to the ground, it often melts on the warm surface of the Earth. the warm surface of the Earth.

SnowSnow

SleetSleet

Sleet refers to a mixture of snow and rain, Sleet refers to a mixture of snow and rain, as well as raindrops that freeze on their as well as raindrops that freeze on their way down. way down.

Sleet, unlike snow, is when raindrops pass Sleet, unlike snow, is when raindrops pass through a liquid form before freezing. The through a liquid form before freezing. The result is that they are not light and fluffy.result is that they are not light and fluffy.

Sleet bounces when it hits the ground.Sleet bounces when it hits the ground.

SleetSleet

Freezing RainFreezing Rain

Freezing rain is sometimes called glaze.Freezing rain is sometimes called glaze. Freezing rain happens when water Freezing rain happens when water

droplets become super-chilled. They do droplets become super-chilled. They do not freeze in air, but freeze the instant they not freeze in air, but freeze the instant they land on an object such as a road, or car. land on an object such as a road, or car.

Freezing Rain / Freezing Rain / GlazeGlaze

HailHail Round balls of ice and snowRound balls of ice and snow Formed, deep within cumulonimbus clouds.Formed, deep within cumulonimbus clouds.

There ice crystals form and begin to fall towards the There ice crystals form and begin to fall towards the Earth’s surface. As this happens, wind gusts pick up Earth’s surface. As this happens, wind gusts pick up the ice crystals pushing them back up high into the the ice crystals pushing them back up high into the clouds. As they begin to again fall down, they grow clouds. As they begin to again fall down, they grow in size. Again, a wind gust might catch the growing in size. Again, a wind gust might catch the growing hail stone pushing it back up high into the cloud. hail stone pushing it back up high into the cloud. This may be repeated several more times, until the This may be repeated several more times, until the hail stone becomes too heavy for the wind to carry, hail stone becomes too heavy for the wind to carry, causing it to finally fall.causing it to finally fall.

HailHail True hailstones occur only at the True hailstones occur only at the

beginning of thunderstorms and never beginning of thunderstorms and never when the ground temperature is below when the ground temperature is below freezing. freezing.

Hailstones can be 2 mm -13 cm.Hailstones can be 2 mm -13 cm. Often several hailstones freeze Often several hailstones freeze

together into a large, shapeless, heavy together into a large, shapeless, heavy mass of ice and snow.mass of ice and snow.

Hail VideoHail Videohttp://www.classzone.com/books/earth_science/terc/content/visuhttp://www.classzone.com/books/earth_science/terc/content/visualizations/es1805/es1805page01.cfm?chapter_no=visualizationalizations/es1805/es1805page01.cfm?chapter_no=visualization

ResourcesResources

http://commons.wikimedia.orghttp://commons.wikimedia.org http://www.geography.hunter.cuny.edu/http://www.geography.hunter.cuny.edu/

~tbw/wc.notes/5.cond.precip/~tbw/wc.notes/5.cond.precip/sleet_formation.htmsleet_formation.htm

www.unitedstreaming.comwww.unitedstreaming.com http://www.kidsgeo.com/geography-for-http://www.kidsgeo.com/geography-for-

kids/0100-atmospheric-moisture.php kids/0100-atmospheric-moisture.php