Chapter 7 Lesson 2 SPI’S: 5.1.8, 5.1.9, 5.1.2, , , 5.1.4, 5.1.6, 1.1.3, (Science, SS, Language, Reading)

Let’s Start with Tornadoes: Tornadoes are the fastest winds on earth. They are concentrated, swirling winds that can cause great damage.

Remember, we learned in the lesson on climate that the sun heats the earth unevenly. The uneven heating of earth plays a role in the forming of thunderstorms and tornadoes.

Most common in spring and summer Form in warm, moist air ahead of an advancing cold front. They begin as a horizontal column of spinning air, then are lifted into a vertical column by the updraft of a thundercloud

Tornadoes typically do not strike the centers of large cities. Heat from cities prevents tornadoes from forming. The path of a tornado is difficult to predict precisely. As winds change, tornadoes may change direction.

Who’d like to read this selection on P. 252?

Air mass Atmosphere Front Mesosphere Stratosphere Thermosphere Troposphere

Air mass – huge volume of air responsible for certain types of weather in a given area.

Atmosphere – mixture of gases that surrounds Earth, made mostly of the two gases; nitrogen and oxygen. This mixture of gases forms 4 main layers: thermosphere mesosphere stratosphere troposphere Look on P. 257 for illustration of Earth’s layers

Let’s read more about air mass and atmosphere on PP. 256 – 258?

Front - a boundary between two air masses, with different properties. Let’s read more about “Fronts” on P. 259 (It will help this definition make more sense.)

How do air masses affect weather?

They bring different conditions as they move into an area.

When does a cold front form?

When cold air moves into an area, forcing warm air to rise up in the atmosphere. (Look at the illustration on P. 259)

Using the map key, what is the temperature in the following cities: Nashville St. Louis Houston Boise Chicago Boston

Let’s read pp. 261 & 262 to see if we can find two types of weather data that can be observed with radar.

Precipitation, and the size, speed, and direction of a storm.

How does the radar image of Hurricane Charley help verify that the eye, or center, of a hurricane is calm?

Radar picks up signals indicating precipitation. The eye of the hurricane is empty, which shows there is no rain.

Why are weather satellites an important tool for weather forecasters?

They orbit high above Earth and can track large storms.

What is an air mass, and what determines its properties?

An air mass is a large volume of air that forms in the troposphere. Its properties depend on where it forms.

How are cold fronts and warm fronts similar and different?

Cold fronts and warm fronts both bring a change in the weather. Cold fronts bring cold air, and warm fronts bring warmer air.

Suppose our area is experiencing thunderstorms. What kinds of changes in the atmosphere led to the formation of the storms?

A cold front moved into the area, forcing warm air up into the atmosphere. Clouds then formed and dropped heavy rains.

Explain how radar images can help to reduce damage from an approaching storm.

With adequate warning, people would have time to board up windows, secure outdoor items, and evacuate.

Be sure to review your notes over chapter 7. The test date will be announced soon. In the meantime… STUDY, STUDY, STUDY!!!