Download Section One: Vocabulary: Weather 4. condensation Humidity 5

Section One:
Vocabulary:
1. Weather
2. Humidity
3. Relative humidity
1.
2.
3.
4.
5.
4. condensation
5. cloud
6. Precipitation
Questions:
What role does runoff play in the water cycle?
It carries water from precipitation into oceans.
What happens when air reaches its dew point?
Relative humidity is 100%.
How is relative humidity affected by the amount of water vapor in the air?
The more water vapor there is in the air, the higher the relative humidity.
What are four types of precipitation?
Rain, snow, sleet and hail
What causes dew?
At night and in the early morning, the air cools and it can hold less moisture. Dew is water
that condenses from the air in the early morning.
Section Two:
Vocabulary:
1. Air mass
2. Front
3. cyclone
4. anticyclone
5. Source region
Questions:
1. What type of weather would you expect an occluded front to produce?
Much precipitation
2. What are the major air masses that influence the weather in the U.S.?
Continental polar, maritime polar, maritime tropical, and continental tropical
3. What are the four major types of fronts?
Cold fronts, warm fronts, stationary fronts, and occluded fronts
4. How do fronts cause weather changes?
Fronts are boundaries between air masses. When a front occurs, air masses of different
temperature and humidity interact. The interactions of air masses cause weather changes.
5. How do cyclones and anticyclones affect weather?
The rising air of a cyclone often causes stormy weather. The sinking air of an anticyclone often
causes dry, clear weather.
6. What kind of weather is associated with a stationary front? Probably cloudy and rainy as long
as the front lies over an area. After the front passes, the weather will usually clear up.
Section Three:
Vocabulary:
1. Thunderstorm
4. tornado
2. Lightning
5. hurricane
3. Thunder
Questions:
1. During a lightning strike, why is lightning seen before thunder is heard?
Light travels faster than sound, so although the two occur at the same time, the sound of
thunder does not reach our ears until after we see the lightning.
2. What is the relationship between lightning and thunder?
Lightning is an electric discharge that forms between clouds or between a cloud and the
ground. The air around the lightning bolt expands rapidly to produce sound waves that we
call thunder.
3. Why don’t hurricanes form over land?
A hurricane gets its energy from the evaporation of enormous volumes of water in warm,
moist air. These volumes of water are not present over landmasses.
4. Explain how tornadoes form.
When wind traveling in two different directions causes the air in the middle to rotate. The
rotating column of air is turned upright by updrafts that begin spinning with it. The
rotating air works its way down to the bottom of the cloud and forms a funnel cloud.
When the funnel cloud touches the ground, it is called a tornado.
5. Explain what causes lightning. The upper part of a cloud usually has a positive charge, and
the lower part of a cloud usually has a negative charge. Lightning is formed when the
opposite charges on the base of one cloud and another cloud or the ground cause an
electrical discharge.
Section Four:
Vocabulary:
1. Thermometer
2. Barometer
3. Anemometer
Questions:
1. What is the purpose of isobars? They connect points of equal air pressure on a weather map.
2. On a weather map, a large H appears over an area in which you live. What kind of weather can
you expect? Dry and clear
3. What does a station model represent? The location of a weather station and the weather data
collected there.
4. Why are so many station models used to gather weather data in the U.S.? The U.S. is very
large, a large number of station models help give a more complete picture of weather and
make weather forecasts more accurate.
5. What information can you get from a weather map? The location and types of fronts, areas of
low and high pressure and predictions of weather for certain areas.