Anticyclones, or highs, are the opposite of depressions – they are areas of high atmospheric pressure that are associated with cool, sinking air. Anticyclones bring settled weather that lasts for days or weeks.
An anticyclone forms when cold air sinks and warms. When air is warming, no clouds can form.
Winds are light and blow out from the centre of the high-pressure cell clockwise.
Characteristics of winter anticyclonesSummer anticyclones bring hot, clear, sunny, settled weather due to:
- Hot days with few or no clouds – temperatures often reach 25 ºC
- Light winds
- Cooling of ground leading to morning dew, which is water vapour on the surface.
Winter anticyclones bring cold, clear, sunny, settled weather due to:
- Cold, sunny days with few clouds.
- Temperatures very cold at night due to rapid heat loss because of the lack of cloud cover in the day time.
- This can bring fog and frost at night or morning dew, which is water vapour on the surface.