1. Air Masses & Fronts

2. What is an AIR MASS? WARM COLD WET DRY
An air mass is a huge body of air that influences weather.
Scientists classify air masses based on:
TEMPERATURE and HUMIDITY
WARM
COLD
WET
DRY

3. Air Masses are named based on where they FORMED…
= TROPICAL
= POLAR
= MARITIME (means sea… wet)
= CONTINENTAL (means land… dry)
WARM
COLD
WET
DRY

4. How are Air Masses named?
WET
DRY
MARITIME
TROPICAL
CONTINENTAL
TROPICAL
WARM
MARITIME
POLAR
CONTINENTAL
POLAR
COLD

5. North American Air Masses
MARITIME POLAR
CONTINENTAL POLAR
MARITIME POLAR
MARITIME TROPICAL
MARITIME TROPICAL
CONTINENTAL TROPICAL

6. How do these air masses move?
MARITIME POLAR
CONTINENTAL POLAR
MARITIME POLAR
Jet Stream
Jet Stream
Prevailing Westerlies
Prevailing Westerlies
MARITIME TROPICAL
MARITIME TROPICAL
CONTINENTAL TROPICAL

7. What happens when air masses meet?
Air masses don’t mix easily.
The line between air masses is called a front.

8. COLD FRONTS

9. WARM FRONTS

10. Watch the BrainPop video on “Weather” and write down 2 things you learned.

11. Use your textbook (pg.133-135) to fill out the chart.

12. Compare/Contrast Chart - Types of Fronts
How it Forms
Type of Weather
Cold
A fast-moving cold air mass overtakes a warm air mass.
Clouds form.
If warm air is humid, rain/snow may fall.
Possible thunderstorms.
Warm Front
Stationary Front
Occluded Front

13. Compare/Contrast Chart - Types of Fronts
How it Forms
Type of Weather
Cold
A fast-moving cold air mass overtakes a warm air mass.
Clouds form.
If warm air is humid, rain/snow may fall.
Possible thunderstorms.
Warm Front
A warm air mass overtakes a slow-moving cold air mass.
Scattered clouds.
Light rain or snow.
May last several days.
Stationary Front
Occluded Front

14. Compare/Contrast Chart - Types of Fronts
How it Forms
Type of Weather
Cold
A fast-moving cold air mass overtakes a warm air mass.
Clouds form.
If warm air is humid, rain/snow may fall.
Possible thunderstorms.
Warm Front
A warm air mass overtakes a slow-moving cold air mass.
Scattered clouds.
Light rain or snow.
May last several days.
Stationary Front
Cold and warm air meet, but neither can move the other. Creates “standoff”
Rain, snow, clouds, or fog that may last for days.
Occluded Front

15. Compare/Contrast Chart - Types of Fronts
How it Forms
Type of Weather
Cold
A fast-moving cold air mass overtakes a warm air mass.
Clouds form.
If warm air is humid, rain/snow may fall.
Possible thunderstorms.
Warm Front
A warm air mass overtakes a slow-moving cold air mass.
Scattered clouds.
Light rain or snow.
May last several days.
Stationary Front
Cold and warm air meet, but neither can move the other. Creates “standoff”
Rain, snow, clouds, or fog that may last for days.
Occluded Front
A warm air mass is caught between 2 cooler air masses. Warm air mass is pushed up.
Temperature gets cooler.
Clouds and rain may form.

16. Surface Map (Fronts & Precipitation)
Warm Front H
High Pressure
Occluded Front L
Low Pressure
Cold Front
Stationary Front

17. Temperature Map

18. H L What will happen to the weather in Little Rock?
Which direction is the warm front moving? L H
12°C
19°C
14°C
20°C
25°C
Tuesday Weather
Little Rock, AR
Clouds & Rain
Warmer = 21°C
Wednesday Weather
Little Rock, AR
Partly Sunny
Warmer = 26°C
Monday Weather
Little Rock, AR
Sun & clear skies
Cool = 15°C
28°C
21°C
26°C
15°C
30°C
Warm Front H
High Pressure
Occluded Front L
Low Pressure
Cold Front
Stationary Front

19. Which direction is the cold front moving?
What will happen to the weather in Nashville?
10°C
8°C
18°C
10°C
11°C
Thursday Weather
Nashville, TN
Partly Sunny
Warm = 20°C
Saturday Weather
Nashville, TN
Sunny
Cool = 10°C
Friday Weather
Nashville, TN
Thunderstorms
Cooler = 15°C
10°C
20°C
15°C
Warm Front H
High Pressure
Occluded Front L
Low Pressure
Cold Front
Stationary Front