1. Add to table of contents:
Tornado scale Pg. 84
Air pressure & wind Pg. 85

2. Air Pressure & Wind
Air pressure - The push of air molecules on a surface or object.
Air with a high density has a greater air pressure and air with less density has a lesser air pressure.
When air heats up it expands and has less air pressure and density.
When air cools down, it contracts and has a greater density and air pressure.

3. IN GENERAL: Hot Air rises = low air pressure
Cold Air sinks = high air pressure

4. Wind - Movement of air
CAUSE: horizontal differences in air pressure.
Air flows from areas of higher pressure to areas of lower pressure.
The unequal heating of Earth’s surface generates pressure differences.
Solar radiation is the ultimate energy source for most wind.

5. Highs and Lows Cyclones are centers of low pressure.
Anticyclones are centers of high pressure.

6. Draw the picture and label