1. Weather
TN Standards: Explain how relationships between the movement and interactions of air masses, high & Low pressure systems, and frontal boundaries result in weather conditions and severe storms.

2. community in Long Island, New York in 2012.
weather can impact people’s lives. Imagine for a moment that you lost your home in an instant. All your possessions ruined. No electricity. No water.
Observe these videos about Super Storm Sandy, a hurricane that changed a
community in Long Island, New York in 2012.
Share with the class your reactions or an time a hurricane impacted your life, (such as Fall Break in Florida).

3. Let’s review! How do each of these affect weather?
Air masses
Fronts
High and low pressure systems (new topic)

4. What is an air mass?
Fill in the blanks in your notes with the words in RED!
An AIR MASS is a large body of air where temperature and moisture content are similar throughout.
Which air masses
form over dry land?
Which air masses
form over the sea?
Which air masses
Are warm? Why?
LIST THE FOUR TYPES
OF AIR MASSES AND
THEIR TWO-LETTER
SYMBOL in your notes
Which air masses
are cold? Why?

5. What are fronts?
Air masses that form from different areas often do not mix because they have different densities.
Warm air is less dense than cold air. When two air masses meet, warm air generally rises, while the cold air sinks.
The area in which two types of masses meet is called a FRONT.

6. Fronts

7. Four kinds of fronts
Turn to your neighbor and describe how the air masses behave in each front.

8. What is weather?
Weather is the mix of events that happen each day in our atmosphere. Weather is different in different parts of the world and changes over minutes, hours, days and weeks.
Most weather happens in the troposphere, the part of Earth’s atmosphere that is closest to the ground.

9. HIGH & LOW PRESSURE SYSTEMS
The weather events happening in an area are controlled by changes in air pressure. Air pressure is caused by the weight of the huge numbers of air molecules that make up the atmosphere.
when air pressure is high, the skies are clear and blue. The high pressure causes air to flow down and fan out when it gets near the ground, preventing clouds from forming.
HIGH & LOW PRESSURE SYSTEMS

10. High & low pressure systems
When air pressure is low, air flows together and then upward where it converges, rising, cooling, and forming clouds.
Remember to bring an umbrella with you on low pressure days because those clouds might cause rain or other types of precipitation.
Memorize this & say to your neighbor:
Pressure’s High, clears the sky…
Pressure’s low, storms will blow!

11. High & low pressure systems
Standing on the ground and looking up, you are looking through the atmosphere. It might not look like anything is there, especially if there are no clouds in the sky.
But what you don’t see is air – lots of it. We live at the bottom of the atmosphere and the weight of all the air above us is called air pressure.

12. High & low pressure systems
A low pressure system has lower pressure at its center than the areas around it. Winds blow towards the low pressure, and the air rises in the atmosphere where they meet. As the air rises, the water vapor within it condenses forming clouds and often precipitation too.
This is called cyclonic flow. On weather maps a low pressure system is labeled with red L.

13. High & low pressure systems
A high pressure system has higher pressure at its center than the areas around it. Wind blows away from high pressure.
This is called anticyclonic flow. Air from higher in the atmosphere sinks down to fill the space left as air blew outward. On a weather map the location of a high pressure system is labeled with a blue H.

14. High & Low pressure systems
Anticyclonic
Flow
Cyclonic
Flow

15. IDENTIFY:
What type of
weather can
you expect in
the areas of high and low
pressure?

16. Air pressure videos
meteorologist
study jams

17. Air pressure demos observe the demonstrations
GET A PIECE OF NOTEBOOK PAPER
WRITE what you think happened to the egg and the can
Illustrate your explanation and label it
Jared’s air pressure science: