1. Dec.20,2018 You need: Clean paper / pencil
HW: What did you learn from the BrainPop?
3rd period: What will happen to Little Rock and to Nashville?
Warm Up:
If we talk about a cold front, what symbol do we use? Which air mass is “winning”?
I CAN: determine cloud types and storm categories
Dec.20,2018

2. Water in the Atmosphere

3. Water Cycle
The movement of water between the atmosphere and earth’s surface is the water cycle.

4. How does water get into the air?
EVAPORATION – is the process where liquid water molecules escape into the air as water vapor.
3 things affect how quickly water evaporates:
1) Temperature
2) Wind
3) Humidity of the air

5. How much water can air hold?
HUMIDITY is the measure of how much water vapor is in the air.
TEMPERATURE affects how much water vapor the air can hold…
Warm Air
Cold Air
holds MORE water vapor.
holds LESS water vapor.
That’s why air feels more “HUMID” on hot days!

6. What is the “Dew Point”?
As air cools, the amount of water vapor it can hold decreases.
At a certain temperature, the water vapor in the air will CONDENSE back into water droplets or ice.
This temperature is the “DEW POINT”.

7. Climate vs Weather Global vs Local winds
LARGE scale = overall pattern, trend
small scale = daily, weekly, small times
Global vs Local winds
LARGE scale = Over the entire Earth
small scale = tiny area…usually land beside water.

8. Global winds 1 2 3 4 5 Polar easterlies Prevailing westerlies
Horse latitudes 4
Trade winds 5
Equator / Doldrums

9. Coriolis Effect – the effect on the air caused by the rotation of the earth.

10. United States of America

11. Air Masses & Fronts

12. 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

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

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

15. How do these air masses move?
MARITIME POLAR
CONTINENTAL POLAR
MARITIME POLAR
Jet Stream
That’s why weather generally moves WEST to EAST
in the U.S.
Jet Stream
Prevailing Westerlies
Prevailing Westerlies
MARITIME TROPICAL
MARITIME TROPICAL
CONTINENTAL TROPICAL

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

17. COLD FRONTS

18. WARM FRONTS

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

20. 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.

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

22. Temperature Map

23. 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

24. 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

25. BrainPop Yesterday! Log in: carrington1 Password: cougars
Watch the WEATHER video and write what you learn.
Watch WIND, HUMIDITY, CLOUDS – video for each. Write two things you learn from each.
Yesterday!

26. Clouds Log in: carrington1 Password: cougars
Watch CLOUDS video. Write two things you learn from the video.
Create your foldable.

27. Storms