1. Weather is the state of the ATM at any given time and place
Have the students brainstorm all of the things that can affect weather. Write on the board, discuss, lead students into talking about air masses. If not on the board, write AIR. Ask: The weather could be sunny in the morning, and stormy in the evening. What causes the sudden change in weather?

2. Weather is associated with:
Pressure Systems
Air masses
Fronts

3. 1. Pressure Systems
As air sinks or rises, areas of high and low pressure form in the atmosphere

4. A high pressure system, air moves away from the center.
Air is not rising to cool and condense into clouds, so it brings nice weather
Draw on the board how high pressure doesn’t form clouds but low pressure does.
Clockwise spin

5. Counter-Clockwise spin
A low pressure system, air moves toward the center then upward
Air rises, cools and condenses into clouds, bringing precipitation
Draw on the board how high pressure doesn’t form clouds but low pressure does.
Counter-Clockwise spin

6. 2. Air Masses
An air mass is a large body of air that have uniform temperature, humidity, and pressure
Review air first, it can be hot, humid, dry, saturated. It can also be cold or warm.

7. Influenced by polar air masses Brings cold weather
Cold Air Mass
Warm Air Mass
Influenced by polar air masses
Brings cold weather
Influenced by tropical air masses
Brings warm weather
Refer back to the water temperature demo – warm water rose, and cold water sank. They didn’t not mix. Air is the same way.

8. Air masses are classified by their temperature and moisture
Continental = land
Maritime = ocean
Polar = cold
Tropical = hot

9. 3. Fronts When two different air masses meet, a front is formed.
A front is the boundary between 2 air masses
Have students cut out front symbols and paste on paper. Paper, glue, scissors

10. Finished? Work on Vocab Textbook page
End with talking about air temperatures. Cold and Warm.
Work on Vocab
Textbook page

11. Front Symbol Air Mass Diagram Weather Notes (leave blank for now)

12. Types of Fronts – Cold Front
Cold fronts form when cold air moves under warm air and pushes the warm air up.
Cold fronts can bring thunderstorms, heavy rain, snow, and cooler temperatures
Cold fronts can move up to twice as fast as warm fronts

13. Types of Fronts – Warm Front
Warm fronts form where warm air moves over cold air
The warm air gradually replaces the cold air
Brings clouds and drizzly rain, with hot temperature

14. Types of Fronts – Stationary Front
Stationary fronts form when both air masses have similar densities
Can bring rain and cloudy weather that lasts for days

15. Types of Fronts – Occluded Front
Occluded fronts form when a fast moving cold front catches up to a warm front
Brings cool temperatures and large amounts of rain and snow