Download PRECIPITATION:

Name: ______________________________ ws#_______
PRECIPITATION:
PART OF THE WATER CYCLE
Clouds that Produce Precipitation
Science/Phipps/Block # ______
Date: _______________
Clouds that Do not Produce Precipitation
Precipitation Notes
COLD AIR
WARM AIR
COLD AIR
HAIL
Updrafts
cause
frozen
pellets
to refreeze
as they rise
and fall
RAIN
Snow melts as
it reaches
warmer air
FREEZING
RAIN
Snow melts,
hits cold air ,
freezes when
it hits cold
surface
SLEET
Snow melts,
refreezes
into ice
SNOW
Snow falls
through
cold air
as it falls,
never melts
RAIN
By far the most common form of precipitation, rain is a drop of liquid water
that has become too heavy to remain suspended in a cloud. The rain that falls may have
started as an ice crystal and as it falls, it melts. This may not be true in the Tropics,
however, where the rain is water that has remained in its liquid state from the cloud to
the ground. Even in the summer, the storms of the middle latitudes often produce rain
that began as an ice crystal because the upper parts of the troposphere are cold.
Raindrops are round, with a somewhat flat bottom. Raindrops range in size from about
two-hundredths of an inch, (0.02 inch) to roughly a quarter of an inch, at which point
they begin breaking up into smaller drops. The typical raindrop is about a 16th of an inch.
The fine drifty stuff that falls from the sky in drops of less than .02 of an inch is called
drizzle.
FREEZING RAIN
Freezing rain is super-cooled raindrops that freeze on impact
with cold surfaces. Storms that produce freezing rain, called ice storms, are some of the
most dangerous and damaging of all weather events. The weight of the accumulating ice
crushes trees and snaps electrical power lines. Layered by nearly invisible ice, roadways
become extremely hazardous.
SLEET
Falling snow may partially melt and then refreeze into a frozen raindrop before
SNOW
Snowflakes are collections of solid ice crystals that assemble themselves as
HAIL
Hail is a large frozen raindrop that is formed inside the enormous cloud of an
it reaches the ground. These ice pellets, easily visible white stuff that bounces off the
ground under these conditions are called sleet. Sleet forms under conditions that are
similar to those that produce freezing rain. The difference is that the lower layer of cold
air is deeper so that the partially melted snowflake or cold raindrop has time to freeze
into an ice pellet before reaching the ground. Sleet can accumulate massive layers of ice,
but its effect is different than the ice layers formed by freezing rain. The pellets do not
accumulate on trees and power lines like freezing rain, and because it is formed by pellets,
the ice layers of sleet are less slippery.
they fall through a cloud. Much precipitation forms firs as ice crystals and then
snowflakes, although if they melt, then they are considered rain. Snowflakes come in
different shapes and sizes.
intense thunderstorm. The cloud contains a powerful updraft that keeps the frozen
raindrop from falling. Super-cooled droplets freeze onto the ice, forming frozen layers.
Eventually, the hailstone is too heavy for the updraft to support any longer, and it falls to
the ground. Hailstones range in size from two-tenths of an inch (0.20), to the size of
softballs.
All precipitation is tricky to measure, because of winds. Rain gauges are straight-sized
tubes or buckets that can be used to collect liquid precipitation. Snow gauges are similar,
but have a flat surface.
Matching: Precipitation
__D_1.
__A_2.
_E _3.
_B__4.
_C_5.
large frozen raindrop formed inside an enormous cloud
the most common form of precipitation
super cooled raindrops that freeze on impact
ice crystals that assemble themselves as they fall through a cloud
falling snow that melts and refreezes into a frozen raindrop before
it hits the ground
A. rain
B. snow
C. sleet
D. hail
E. freezing rain
WATER CYCLE REVIEW
Label the following diagram using the word bank:
condensation respiration
evaporation
transpiration precipitation
condensation
evaporation
transpiration
precipitation
respiration
True or False:
_T__1. As water vapor rises in the troposphere is cools.
_F__2. Warm water vapor rises in the troposphere because it becomes less dense.
_F__3. Water vapor moves up in the air and forms clouds through transpiration.
_F__4. Animals give off water vapor through the process of photosynthesis.
_F__5. Transpiration occurs in animals.
_T__6. Water travels in an endless cycle.
_F__7. Dew is an example of evaporation.
_T__8. The formation of a cloud is due to condensation.
_F__9. Evaporation is the process of a gas changing into a liquid.
_T__10. Condensation is the process of a gas changing into a liquid.