Transcript Precipitation - Laconia School District

Precipitation
• Chapter 16 section 5
• November 29, 2007 T-4
• Hannah, Steven, Gabby, Robbie
Vocabulary
• Precipitation: Is any form of water that
falls from clouds and reaches Earth’s
surface.
• Drought: Is a water shortage caused by
long periods of low precipitation in a
particular area.
• Rain Gauge: Is an open-ended can or
tube that collects rainfall.
Rain
• Is drops of water that are at least 0.5
millimeters in diameter.
• Is the most common form of precipitation
• It is measured in a rain gauge.
Sleet
• Is raindrops falling through a layer of air
below 0 degrees Celsius. As they fall, the
raindrops freeze into particles of ice.
• Ice particles smaller than 5 millimeters
in diameter is sleet.
Freezing Rain
• Is raindrops that
freeze when they
touch a cold surface
instead of freezing
when they touch the
ground.
Hail
• Are round pellets of ice
larger than 5 millimeters
in diameter.
• Hail is only formed in
cumulonimbus clouds
during thunderstorms.
• During the thunderstorm
strong updrafts carry the
ice pellet up and down
cold regions.
• Each time it passes a
cold region a layer of ice
is formed around it until
it is heavy enough to fall.
Snow
• Is water vapor in
clouds that is directly
converted into ice
crystals or
snowflakes.
• Snow is measured in
a rain gauge.
• Every snowflake has
6 sides and is unique.
Measuring Precipitation
• Meteorologists measure
precipitation with rain
gauges.
• A rain gauge is an open
ended can or tube that
collects precipitation.
• To measure how much
precipitation is in a can put a
ruler in it.
• For more precipitation add a
funnel, that gives you ten
times more of a certain kind
of precipitation. When
measuring it for accuracy
divide by 10.
Controlling Precipitation
• When droughts occur airplanes sprinkle
dry ice (solid carbon dioxide.) and silver
iodide into clouds.
• Water vapor in the clouds condenses the
particles of silver iodide forming rain or
snow.
Georgia’s Drought
5 Facts About Georgia’s Drought
• The drought in Georgia is a level 4
• Atlanta Georgia is 15 inches below their normal
precipitation .
• There is about a three-month supply of water left
in Lake Lanier.
• Atlanta Georgia is down to a 90 day supply of
water.
• The drought responds to all counties in the north,
such as Muscogee, Spalding, and Lincoln
counties.
What Must Happen Before
Precipitation can Fall To The Ground
Cloud droplets or ice crystals must grow
heavy enough.