Weather Study Guide
Sol 4.6
What type of weather is associated with a high
pressure air mass?
The measure of the amount of heat energy in the
atmosphere. A thermometer is used to measure
air temperature.
The weight of the air. It is determined by many
factors including the temperature of the air. A
barometer is used to measure air pressure.
Changes in air pressure allow us to predict
changing weather patterns.
High pressure air masses usually bring dry,
clear conditions.
What type of weather is associated with a low
pressure air mass?
Low pressure air masses usually bring clouds,
rain, and wind.
What is a front?
A front is a boundary between air masses of
different temperature and humidity.
How is a cold front formed?
A cold front is formed when a cold air mass
pushes into a warm air mass. This heavy cold air
sinks and creates a high pressure area. A cold
front will often produce thunderstorms, followed
by dry, clear conditions.
How is a warm front formed?
A warm front is formed when a warm air mass
pushes into a cold air mass. As the warm air
rises, a low pressure area is created. A warm
front will sometimes produce light rain.
Describe cirrus clouds and tell what weather
conditions are associated with them?
Cirrus clouds are feathery, look like wisps of
hair high in the sky, and are made from tiny ice
crystals. They are associated with fair weather.
Cirrus clouds often indicate that rain or snow will
fall in several hours.
Describe stratus clouds and tell what weather
conditions are associated with them?
Stratus clouds are smooth, gray clouds that
cover the whole sky (like a blanket),blocking out
direct sunlight. Light rain and drizzle are usually
associated with stratus clouds. Fog is a created
when stratus clouds are low to the Earth.
Describe cumulus clouds and tell what weather
conditions are associated with them?
Cumulus clouds are fluffy and white with flat
bottoms and look like big cotton balls in the sky.
They usually indicate fair weather.
What is temperature?
What is air pressure?
Describe cumulo-nimbus clouds and tell what
weather conditions are associated with them?
What is precipitation?
How is rain formed?
How is snow formed?
How is sleet formed?
How is hail formed?
Cumulo-nimbus clouds are formed by cumulus
clouds that join together. They become so full of
moisture, they turn dark and heavy, often
resulting in thunderstorms with heavy rains,
thunder, and lightning.
Precipitation is any form of water that falls from
the atmosphere to Earth’s surface. Precipitation
is measured with a rain gauge. Precipitation
includes rain, snow, sleet, and hail.
Water vapor in the atmosphere condenses,
changing from gas to liquid. These liquid water
droplets become too heavy and fall to the ground.
Snow is formed when the water droplets in the
clouds freeze high in the atmosphere, forming ice
crystals. These ice crystals attach to each other
and become heavier. When they weigh too
much, they fall to the ground as snow.
Sleet is formed when ice crystals fall, but the air
temperature is just above freezing, so some of
the ice crystals melt and some remain frozen.
Hail is formed when raindrops are frozen into
crystals in a storm cloud. Winds produced by the
storm cause the frozen ice crystals to repeatedly
rise and fall, melting and freezing again. This
causes layers of ice to form around the original
ice crystal. When it becomes very heavy, it falls
as a ball of ice.
How are hurricanes formed and what type of
weather is associated with them?
Hurricanes are formed when small
thunderstorms over the ocean grow larger as
they take in more and more heat and moisture
from the warm ocean water. They have strong
winds that move in huge circles. Hurricanes are
the largest storms on Earth!
How are tornadoes formed and what type of
weather is associated with them?
Tornadoes are formed during thunderstorms as
a column of warm air begins to spin upward
forming a funnel cloud. A tornado is MUCH
SMALLER than a hurricane. Tornadoes have
extremely strong circular winds and can be the
most violent type of storm.
What is a meteorologist?
A meteorologist is a person who gathers data
about weather using a variety of instruments.
What does a barometer measure?
air pressure
wind speed
What does an anemometer measure?
precipitation
What does a rain gauge measure?
temperature of the air
What does a thermometer measure?