In an anticyclone (also referred to as a 'high') the winds tend to be light and blow in a clockwise direction. Also, the air is descending, which inhibits the formation of clouds. The light winds and clear skies can lead to overnight fog or frost. If an anticyclone persists over northern Europe in winter, then much of the British Isles can be affected by very cold east winds from Siberia (Fisherman's saying: 'When the wind blows east the fish feed least'). However, in summer an anticyclone in the vicinity of the British Isles often brings fine, warm weather.