Download Forms of Precipitation - MacIntyreEarthScience

Water in the Atmosphere
 Chapter 18
Forms of Precipitation
 Precipitation in any ______________
of water that falls to the Earth's
surface.
Types of Precipitation
 The type of precipitation that falls to
the ground depends upon the
formation process and the
_____________________ of the
environment between the cloud and
the surface
 ______________
 ______________
 ______________
 ______________
 __________________
______________
Rain
 Rain develops when growing cloud
__________________ become too
heavy to remain in the cloud and as a
result, ______________ toward the
surface as rain
 Rain can also begin as ice
__________________ that collect to
form large snowflakes
 As the falling snow passes through
the freezing level into warmer air, the
flakes ______________
Snow
 Snow is formed when ice crystals
form from _______________ vapor
that is in the clouds directly above
your heads!
 This process is called
________________
Hail
 Hail is formed when
__________________ carry raindrops
upwards into extremely cold areas of
the atmosphere
 There the ___________________
merge and freeze. When the frozen
clumps get too heavy, they
_______________ to earth
 Hail can vary in size, from the size of
a small stone to that of a
__________________! So be careful
Sleet
 Sleet is ________________
raindrops. Sleet begins as rain or
snow and falls through a deep layer of
cold air that contains
______________________ below
freezing that exist near the surface.
 Rain that falls through this extremely
cold layer has time to
________________ into small pieces
of ice
Freezing Rain
 Freezing rain is falling rain that cools
below ______________, but does not
turn to ice in the air
 The water is
“_____________________”
When the drops hit anything they
instantly turn to ice!
Humidity and Relative Humidity
 Humidity is the amount of water
_______________ in the air
 Relative humidity is a measure of the
______________ of water vapor that
the air is holding, compared to the
amount it can hold at a
_____________ temperature
 When the air is holding as much
________________ as it can, it’s said
to be saturated
 In the cool of the morning, the air
_______________ hold as much
moisture. We often have dew on a
summer _________________
 Once the air has warmed, the relative
humidity _______________ since the
air can hold more moisture
 The cold air around the glass causes a
_______________ temperature at
which the air is saturated
 The temperature at which air is
saturated and condensation takes
place is the _____________
_______________
Understanding Clouds
 Clouds form as warm air is forced
________________
 As the air is forced upward, it
expands and _______________
 As the air cools, the relative humidity
reaches ________________
Water vapor begins to condense in tiny
drops around nuclei. Nuclei are small
particles of dust, salt, and smoke in the
atmosphere.
Stratus Clouds
 Stratus clouds form a smooth, even
_______________
 They usually form at _____________
altitudes
 When air is cooled and condenses
near the ground, a stratus cloud
known as _____________ forms
Cumulus Clouds
 These are masses of
_______________, white clouds,
often with flat bases
 They form when air currents
______________
 They can be associated with both fair
weather and…….when they get really
tall ____________________!
Cirrus Clouds
 Cirrus clouds are ______________,
______________, white, feathery
clouds containing ice crystals
 Cirrus clouds are usually associated
with ______________ weather, but
they may indicate approaching storms
Cloud Types
 There are many different cloud types
 Can you think of the two main ways
that clouds are classified?
 _______________,
_______________, and sometimes
___________ _______________
By Shape!
There are three main cloud types that are
based on shape
 _________________
 _________________
 ________________
By Height!
 The prefix of cloud names can
describe the height of cloud bases
 _______________: High clouds
above 6000m
 ______________: Middle elevation
clouds between 2000 to 6000m
 ________________: Low level clouds
below 2000m
Rain!
 ________________ clouds are dark
clouds associated with precipitation
 When a nimbus cloud is also a
towering cumulus cloud, it’s called a
______________________ cloud