1. Weather Patterns and Severe Storms
Chapter 20
Air Mass
- large body of air with a consistent temperature
and moisture.
- as it moves, it changes the weather and may
change itself.

2. * U.S. affected most by cP and mT*
Air Mass Types
1) Continental Tropical (cT)
- warm, dry air from the land
2) Continental Polar (cP)
- cold, dry air from the land
3) Maritime Tropical (mT)
- warm, moist air from the ocean
4) Maritime Polar (mP)
- cold, moist air from the ocean
* U.S. affected most by cP and mT*

3. Air Masses Are Classified by Region

4. Fronts - boundary separating 2 air masses Types 1) Warm Front
- warm air moves into area with cold air in place.

5. 2) Cold Front
- cold air moves into area with warm
air in place.

6. 3) Stationary Front
- warm & cold air move side by side
(not against each other)

7. 4) Occluded Front
- cold front that takes over a warm front

8. Severe Weather Thunderstorms 1) Formation
- warm, moist air rises into unstable air
- develops in low, cumulus clouds
2) Characteristics
- lightning, thunder, heavy rain, wind, hail

9. Tornados 1) Formation a) air rotates(rolls) horizontally within a
thunderstorm
b) rolling air (vortex) rises up vertically
c) once vertical, tornado is formed
2) Characteristics
- extremely low pressure inside
- air is sucked in, towards a tornado
- winds between mph.

10. Formation of a Tornado

11. Hurricanes 1) Formation a) thunderstorms gather over warm ocean water
b) strong, low pressure system builds
c) If ocean water is warm enough:
- low pressure becomes a hurricane
2) Characteristics
- very low pressure inside
- winds 74 mph or greater

12. Hurricanes consist of:
1) Eye
- calm center of storm
2) Eye Wall
- strongest storms around eye
3) Rain Bands
- rain clouds drawn into center
4) Storm Surge
- ocean water pushed ahead by
the storm

13. Cross Section of a Hurricane

14. Satellite View of Hurricane Floyd