1. Unit 4
Lesson 5
Weather and Climate
S8.D

2. Weather vs Climate Weather Climate
Is the condition of the atmosphere including temperature, pressure, and humidity at a particular time and place
Climate
Is the average weather of an area over a long period of time
Warmer climates exist near equator and colder climates exist near poles

3. Earths Atmosphere
Temperature changes and the atmosphere

4. Air Masses
A large body of air that has the same temperature and humidity throughout
 the amt of water vapor in the air
air masses take on the characteristics of the area over which they form
over sea (maritime) wet
over land (cont.)  dry
they move in certain directions

5. Air Pressure Also called Barometric Pressure
Is the weight of the air pushing down on a particular area
Pressure system
 region of atmosphere that has a similar barometric pressure throughout
 Two types
High Pressure System
Low Pressure System

6. High Pressure System Generally produces clear, dry skies
Predicting Weather
If the barometric pressure is rising, a high pressure system is moving in and weather will clear up

7. Low Pressure System Often brings rain or snow Predicting Weather
If the barometric pressure is dropping, a low pressure system is moving in and weather will become cloudy and rainy/stormy

8. Clouds
When air rises it cools and the water vapor in the air condensed into tiny liquid droplets which make up a cloud
Nimbus
producing precipitation

9. Stratus clouds Cumulus Clouds Cirrus Clouds
associated with overcast days
Cumulus Clouds
puffy white clouds on fair days
Can turn into storm clouds
Cirrus Clouds
high, feather-like clouds associated with clear sunny days

10. Clouds

11. Prevailing Winds
Winds close to the earth’s surface that consistently blow in the same direction
Can affect an area’s climate

12. Effect of Water on Weather
Large bodies of water (oceans) can store large amounts of heat
During Cold Months: If water is warmer than air, heat will move to air, bringing warmer weather to cold areas
During Hot Months: If air is warmer than cool water, heat will move to the water, bringing cooler weather to warm areas

13. Effect of Water on Weather
Because water warms and cools so slowly relative to land and air, areas near large bodies of water tend to have more stable temperatures
Places located near large bodies of water have warmer winters and cooler summers.
Myrtle Beach will have warmer winters and cooler summers than Columbia

14. Lake-Effect Snow Cold arctic air blows over warmer Great lakes
Air close to lake becomes warm and moist and rises
As it rises, water vapor condenses into clouds
As clouds move over opposite shore, they release snow

15. Lake-Effect Snow