1. How Does air move across the surface?
Pressure Systems
How Does air move across the surface?

2. PRESSURE SYSTEMS
Where’s the HIGH?
Where’s the LOW? H L

3. H CHARACTERISTICS SPIN CLOCKWISE Cool Temperature Dry (low humidity)
HIGH PRESSURE SYSTEMS…
Air SINKS and MOVES AWAY from a HIGH!
CHARACTERISTICS
SPIN CLOCKWISE
Cool Temperature
Dry (low humidity)
Clear Weather
“Highs are Happy” H

4. WINDS BLOW AWAY FROM HIGH PRESSURE CENTERS
WIND DIRECTION
WINDS BLOW AWAY FROM HIGH PRESSURE CENTERS *3

5. COOL DRY AIR SINKS NO CLOUDS COOL CLEAR WEATHER
                                                                      
                                    

6. L CHARACTERISTICS SPIN COUNTER- CLOCKWISE Warm Temperature HUMID
LOW PRESSURE SYSTEMS…
Air moves into and rises in a LOW!!
CHARACTERISTICS
SPIN COUNTER- CLOCKWISE
Warm Temperature
HUMID
CLOUDY Weather
Precipitation likely!
“LOWS are LOUSY” L

7. WINDS BLOW TOWARD FROM LOW PRESSURE CENTERS
WIND DIRECTION
WINDS BLOW TOWARD FROM LOW PRESSURE CENTERS

8. CLOUDY WEATHER with PRECIPITATION
WARM HUMID AIR RISES
CLOUDS FORM
CLOUDY WEATHER with PRECIPITATION
                                    
                                                                      

9. LOW PRESSURE SYSTEM

10. AIR MOVES FROM HIGH TO LOW PRESSURE
THIS MAKE WIND!

11. H L WIND CREATED BY PRESSURE DIFFERENCES
In which direction is the air mainly moving?
Isobars are close together
Steep pressure gradient
Isobars are far apart
Low pressure gradient H L
Where is the wind blowing the fastest?