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High pressure and anticyclones

A high pressure system is called an anticyclone.

  • Air falls in an anticyclone so no clouds are formed.
  • In summer, high pressure usually results in clear skies, gentle breezes and fine weather.
  • In winter high pressure leads to clear skies and colder conditions.
  • There is less wind as the isobars are further apart
  • Anticyclones tend to move in a clockwise direction.
Map showing path of a typical anticyclone

You can recognise an anticyclone on a weather chart as the isobars are above 1000mb and spread further apart.

Anticyclones tend to last longer than depressions. For example, an anticyclone can last for two weeks whereas a depression lasts 2-3 days.

Question

Are the following statements true or false?

  1. High pressure bring an anticyclone weather system.
  2. High pressure is shown on an isobar map when the numbers are 1000mb or below.
  3. Anticyclones will bring rain.
  4. Winds will be calmer in an anticyclone.
  5. Anticyclones move in an anticlockwise direction.