1. Aim: How are winds created?
Do Now: In your notebooks answer the following questions.
Near which letter are the strongest winds located?
What are the lines on this map called? A B C

2. I. Wind
Wind: is the movement of air from high pressure to low pressure.
H L

3. Wind is blowing from the west
- Wind direction is named based on where wind comes from. N S
W E
Wind is blowing from the west

4. Wind direction is measured using a wind vane
Wind speed is measured using an anemometer.
If wind blows from one direction mostly, it is called a prevailing wind.
* In the U.S., the westerlies constantly move weather west to east.

5. A large blue H indicates the center of high pressure
II. Pressure Systems
- Differences in temperature create differences in pressure which creates wind.
1. High Pressure System (anticyclone)
Air Temperature:
Moisture content:
Vertical Movement:
Weather conditions:
Rotation:
cooler
dry air
sinks at center
Happy weather (dry/sunny)
A large blue H indicates the center of high pressure

6. a large red L marks the center of low pressure
2. Low Pressure System (Cyclone)
Air Temperature:
Moisture content:
Vertical Movement:
Weather conditions:
Rotation:
warmer
moist air
rises at center
Lousy weather (wet/cloudy)
a large red L marks the center of low pressure

7. Low Pressure:
Rotates
Counterclockwise and
inward to the center.
High Pressure:
Rotates Clockwise and
Outward from the center.

8. III. The Coriolis Effect
Curves the path of air and ocean currents across the Earth.
Caused by the rotation of the Earth
Northern Hemisphere = curved to the right
Southern Hemisphere = curved to the left

9. Cyclones and anticyclones move in the opposite direction in the Southern Hemisphere.

10. IV. Weather Forecasting
Weather reports emphasize the locations and possible paths of cyclones and anticyclones (High and Low pressure).
* Low-pressure centers can produce bad weather in any season.

11. Closure 1:
In your notes, list the characteristics for high and low pressure systems.
H L
High Pressure
Heavy Air (Sinking)
Happy Weather
Clockwise
Out
Low Pressure
Light Air (Rising)
Lousy Weather
Counterclockwise In

12. Take a “How do Winds Form” worksheet from the back bottom bin.
Closure 2:
Take a “How do Winds Form” worksheet from the back bottom bin.
Complete both sides.