Precipitation By: Brittany Erickson and Kacie Vierhuf

DefinitionWhen the clouds become too big and heavy with water droplets, the

water starts falling to earth as either rain, fog, mist, dew, snow or hail depending on how cold it got high up in the atmosphere.

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Different Types of Precipitation

Dew

Mist

Fog

Rain

Hail

Snow

Dew Dew is water in the form of

droplets that appears on thin, exposed objects in the morning or evening

When surface temperature drops, eventually reaching the dew point, atmospheric water vapor condenses to form small droplets on the surface

Because dew is related to the temperature of surfaces, in late summer it is formed most easily on surfaces which are not warmed by conducted heat from deep ground, such as grass, leaves, railings, car roofs, and bridges

Mist • Mist is a phenomenon of small droplets suspended in air

Common in cold air above warmer water, in exhaled air in the cold

The difference between mist and fog is visibility If we can see between 1

and 2km, we call it mist

Mist is a milder form of fog

Fog Fog is a collection of water

droplets or ice crystals suspended in the air at or near the Earth's surface

While fog is a type of a cloud, the term "fog" is typically distinguished from the more generic term "cloud" in that fog is low-lying, and the moisture in the fog is often generated near bodies of water

Fog begins to form when water vapor condenses into tiny liquid water droplets in the air

Fog forms when the difference between the temperature and dew point is generally less than 4 degrees F

Rain

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Measured by a rain gauge in tenths Rain gauge is a device

that measures the amount of rain that falls

Liquid precipitation

Rain requires the presence of a thick layer of the atmosphere to have temperatures above

the melting point of water near and above the Earth's surface.

Rain drops range in size from oblate, pancake-like shapes for larger drops, to small spheres

for smaller drops.

Hail

Hail forms when droplets of water freeze around a small core of ice. Hail stones increase in size by adding extra layers of ice as they are tossed up and down by rising and falling air in thunderstorms.

Hail is a form of solid precipitation which consists of balls or irregular lumps of ice, that are individually called hail

stones

Measured by comparing it to familiar sized objects such as a quarter, golf ball, baseball, etc.

Or measured by a ruler.

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Intensity of hail Measured from H0 to H10

depending on the intensity and size of hail

Snow

Snow forms when water vapor in the air changes directly to ice. Snowflakes are usually 6-sided ice crystals. The air temperature must be less than 0°C for snow to form

Measured by a measuring stick. Put a snowboard on the

old snow to measure new snow, clean it off each time it is done snowing.

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Activity

Instructions Step 1: cut off the top 1/3 of a clear plastic pop

bottle. Take the top off the bottle and invert the top third into the lower 2/3 of the bottle (it now acts as a funnel for collecting the rain water).

Step 2: Put some pebbles into the bottom of the bottle then secure the two parts of the bottle together using tape

Step 3: Either stick the clear plastic ruler to the side of the bottle with tape just above the level of the pebbles or you can draw a scale onto some masking tape using the ruler then stick the masking tape straight onto the bottle.

Step 4: Fill the bottle with water up to the ‘0’ at the bottom of your measuring scale or ruler. This becomes the bottom of the rain gauge.

Step 5: Put the gauge in an open area where it is exposed to rain but where it won’t be easily knocked over

Step 6: Monitor rainfall each day by reading how many millimeters the water level has risen

Step 7: Before a big downpour, make predictions on how many millimeters of rain is going to fall

Bibliography http://en.wikipedia.org/wiki/Fog

http://en.wikipedia.org/wiki/Mist

http://en.wikipedia.org/wiki/Dew

http://shoalwater.nsw.gov.au/education/precipitation_experiment.htm

http://shoalwater.nsw.gov.au/education/precipitation.htm