1. AIR MASSES AND FRONTS
Chapter 3 Section 1

2. Air Masses
Air masses take on the characteristics of the area where they form.
Air mass temperature and moisture are consistent throughout.
Warm air forms over tropical regions near the equator.
T- Tropical
Cold air forms over polar regions.
P- Polar
Wet air masses form over water
m- maritime
Dry air masses from over land.
c- continental

3. Air masses Moisture content is noted by the first letter.
m – maritime – wet
c – continental – dry
Temperature is noted by the second letter.
P – polar – cool
T – tropical - warm

7. Air Masses mP- maritime polar air mass cP – continental polar air mass
mT – maritime tropical air mass
cT – continental tropical air mass

8. How Air Masses Move In the continental U.S. air masses are moved by:
prevailing westerlies – west to east movement
jet steams.

9. Fronts A front is a boundary between air masses. Cold front Warm front
Four types of fronts and map symbols
Cold front
Warm front
Occluded front
Stationary front

10. COLD FRONT
Cold air mass meets a warm air mass and pushes the warm air mass out of its way.
Bring thunderstorms, rain or snow.
Most tornadoes develop from
thunderstorms on the edge of a cold front.
Cold front followed by cooler drier air.

11. WARM FRONT
Warm air mass meets a cold air mass and pushes the cold air mass out of the way.
Brings drizzly precipitation.
Followed by clear warm weather.

12. STATIONARY FRONT Cold air meets warm air.
Not enough force to move either front.
Many days of cloudy, wet weather.

13. OCCLUDED FRONT Warm air caught between two cold air masses.
Brings cool temperatures with large amounts of rain or snow

14. Cold Front, Warm Front and Occluded Front Animation
Click on the above links.

16. Cyclone Area with lower pressure than surrounding area.
Winds spiral toward the center.
Rising air causes stormy weather.
Hurricanes that from over the Indian Ocean are called cyclones.

17. Anticyclone Rotation of air around high pressure center.
Dry, clear weather
Winds spiral outward

18. Quiz: Take this on the paper provided.
1. Describe a maritime polar (mP) air mass, in terms of moisture and temperature.
2. What is the name of an air mass that forms over water?
3. What is the name of an air mass that forms over land?
4. What is the name of an air mass that forms in a cold region?
5. What is the name of an air mass that forms in a warm region?
6. Describe a continental tropical (cT) air mass, Moisture and temperature.
7. The boundary between two air masses is called a ______________________.
8. A cold air mass meets and pushes a warm air mass out of the way.
What type of front am I?
9. A warm air mass is trapped between to cold air masses.
10. A warm air mass meets and pushes a cold air mass out of the way.
11. I am a front that brings drizzly rain and am followed by warm clear weather. Name me
12. A cold air mass meets a warm air but neither is very strong. They are separated and many days of wet , cloudy weather occur.