16.5 Precipitation

Precipitation

• Precipitation is any form of water that falls from clouds and reaches Earth’s surface.– Not all clouds produce precipitation– Cloud droplets or ice crystals must grow

heavy enough to fall through the air.– Grow by colliding with other droplets.

Types of Precipitation

• Common Types of Precipitation– Rain– Sleet– Freezing Rain– Hail– Snow

Types of Precipitation• Rain

– Drops less than 0.5mm

– Most common. Usually fall from nimbostratus clouds.

• Freezing Rain– Rain that freezes

when it touches a cold surface.

Types of Precipitation

• Sleet– Rain that freezes

into ice.– Less than 5mm in

diameter.

• Hail– Pellets of ice larger

than 5mm.– Form in

cumulonimbus clouds

Measuring Precipitation

• Meteorologists measure rain with a rain gauge.– Collects rainfall with a

funnel.– Depth divided by ten.