Chapter 7 Study Guide
Section 1
How does sleet differ from snow? It starts as rain and freezes in the air.
What are large thunderhead clouds that produce precipitation called?
cumulonimbus clouds.
What happens when air reaches its dew point? Relative humidity is 100%
What role does runoff play in the water cycle? It carries water from precipitation
into oceans.
What can strong updrafts within a thunderhead produce? Hail
Which describes an altocumulus cloud? Puffy mid-level clouds
What type of cloud forms in layers? Stratus
What kind of weather will nimbostratus clouds likely bring? Light to heavy steady
rain or snow
What is the process in which a gas becomes a liquid called? Condensation
What is the process in which a liquid becomes a gas? Evaporation
What happens to relative humidity if temperature decreases and humidity stays the
same? It increases
How does freezing rain differ from hail? Freezing rain begins as rain then freezes as
it hits a surface.
What is the most common type of precipitation? Rain
What are high, wispy clouds made of ice crystals called? Cirrus
What types of clouds are puffy and white and have flat bottoms? Cumulus
What is relative humidity? The amount of water vapor in the air compared to the
maximum amount of water vapor that the air can hold at a certain temperature
What is the relative humidity of air at its dew point? 100%
What type of cloud is fog? Stratus
What determines what type of precipitation will reach the ground? The temperature
What is the movement of water vapor from the stomata in the leaves of plants to the
atmosphere? Transpiration
What is the process in which water on the ground soaks into the soil? Infiltration
Section 2
What kind of front forms when a cold air mass moves under a warm air mass and pushes it up?
A cold front
A continental polar air mass which has cold dry air forms where? In northern Canada
Why do meteorologists track cyclones and anticyclones? because they help predict stormy or
clear weather
What is a front that forms when a warm air mass is trapped between cold air masses and is
forced to rise? An occluded front
What kind of weather does a stationary front bring? Many days of cloudy, wet weather
What kind of weather would an anticyclone likely bring? Dry and clear
How does a warm front form? Warm air moves over cold air and replaces it
What kind of weather would an occluded front likely bring? much precipitation
A maritime tropical air mass contains what kind of air? Warm, wet air
How do winds behave in a cyclone? They spiral toward the center and rise.
What kind of air does a Continental tropical air mass contain? Warm, dry air
What kind of front forms when warm air moves over cold air and replaces it? Warm front
What is a large body of air where temperatures and moisture content are constant throughout?
Air mass
What are areas that have lower pressure than the surrounding areas called? cyclone
What is an area where two air masses meet called? Front
What are areas that have high pressure where air masses move apart and sink called?
Anticyclones
What kind of air does a Maritime Polar air mass have? Cold, damp air
What kind of weather is associated with a cold front? Thunderstorms, rain, or snow
What weather symbol has red semi-circles and blue triangles? Stationary front
What weather symbol has red lines and red semi-circles? Warm front
On which side of the warm front symbol will cold air be located? On the side with the
semicircles
What weather symbol has purple triangles and semicircles? Occluded front
What weather symbol has blue lines and blue triangles? Cold front
On which side of the stationary front symbol will the warm air be? On the side with the triangle
Section 3
Wind moving in two directions over a prairie makes air in the middle spin. Of what is this beginning?
a tornado.
What is a severe storm that forms as a rapidly rotating funnel cloud? tornado
What makes a tornado dangerous? mostly because of its strong winds
What are the most powerful storms on Earth? hurricanes
How can the eye of a hurricane be described? Has warm, calm air and light winds
Finding a high place to wait is a safety measure during what kind of weather? Flash flood
If there is a tornado warning for your area, what should you do? Go to a room with no windows
A storm surge is a dangerous part of what? A hurricane
Lightning is an electric discharge between what? A positively charged area and a negatively charged area
What makes a tornado dangerous? Mostly because of the strong winds
What conditions contribute to the decrease in a hurricane’s strength as it moves from the ocean onto land?
A lack of warm, moist air over land
Why do meteorologists track cyclones and anticyclones? Help predict stormy or clear weather
What is a swelling wall of water called that develops in a hurricane over the ocean because of low atmospheric pressure
and heavy winds? Storm surge
If a high pressure system is sitting over a city and a low pressure system is sitting to the east, what will most likely
happen? The high pressure system will move east to the low pressure system.
Under what conditions are hurricanes most likely to form? When thunderstorms meet over warm ocean water
Section 4
Which instrument measures air pressure? Barometer
How do isobars help meteorologists? By showing high and low pressure areas
Which instrument measures wind speed? Anemometer
What can you find on a weather map? The location of cold and warm fronts, areas of high and low pressure, expected
precipitation
Which instrument has a wet and dry bulb thermometer and measures relative humidity? Sling psychrometer
Where do images of weather systems shown on television come from? Weather satellites
Which weather tool measures air temperature? Thermometer
Which instrument measures the amount of liquid precipitation? Rain gauge
Which tools measure wind direction? Wind sock and wind vane
Which tool measures humidity? Hygrometer
Which instrument tracks the location, movement, and amount of precipitation? Radar
Where are fronts associated with weather located? In the middle latitudes
Also be familiar with your station model symbols and their meanings on your weather sheet.