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?

Weather is associated with: Pressure Systems Air masses Fronts

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

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

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

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.

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.

Air masses are classified by their temperature and moisture Continental = land Maritime = ocean Polar = cold Tropical = hot https://www.youtube.com/watch?v=kvk-hBFnBTI&list=PLo6bQyjjpSGr9Pyv_lkvEAfOYPm2GHR24&index=4

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

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

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

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

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

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

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