1. STANDARD GRADE ANTICYCLONES John Smith Invergordon Academy

2. HIGH PRESSURE SYSTEMS
High pressure systems are also known as anticyclones

3. HIGH ATMOSPHERIC PRESSURE
Outer edge of the atmosphere
The Earth’s atmosphere presses down on the surface of the Earth.
Cold, dense air falls. This increases the weight of the air pressing down on the Earth’s surface.
The Earth’s surface

4. WHAT CAUSES HIGH PRESSURE?
When air high in the atmosphere is cold, it falls towards the earth’s surface.
Falling air increases the weight of air pressing down on the Earth’s surface.
This means that air pressure is high.

5. WHAT WEATHER DOES HIGH PRESSURE BRING?
As the cold air falls through the atmosphere, it becomes slightly warmer.
Because warm air can hold more moisture than cold air, no condensation or clouds occur.
There are no warm or cold fronts in high pressure areas.
This means that high pressure systems bring clear skies.
Winds are usually light, and blow out of the high pressure area.

6. HIGH PRESSURE IN WINTER
High pressure in winter gives us
clear skies
very low temperatures
calm, or light winds
no precipitation
frosty conditions

7. HIGH PRESSURE IN SUMMER
gives us
clear skies
high temperatures
calm, or light winds
no precipitation
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