Drama plays out over Caithness with spectacular cloud formations
The sky over Caithness was filled with a colourful display of lenticular clouds yesterday afternoon and captured in a series of dramatic images reproduced here.
The photographs were taken from the Watten area facing southwest across the Caithness moors at around 4pm as the sun gradually went down.
Enormous clouds filled the sky over the distant Scaraben hills and created lenticular formations high in the air that gradually changed colour from a golden yellow to a rosy red.
The Met Office says that these "lens-shaped orographic wave clouds" form when the air is stable and "winds blow across hills and mountains from the same or similar direction at different heights through the troposphere".
Wick weather watcher Keith Banks who writes a monthly column for the paper said: "These striking and unusual looking lens or disc-shaped clouds are examples of Altocumulus lenticularis.
"In brief, they form when a warm and moist air mass is blowing at right angles, across a range of mountains. When this happens a wave like motion of the air can be generated on the sheltered downstream, or lee side of the mountains.
"In the crests of the waves, the air has moved upwards, expands and sometimes cools enough for condensation to occur, causing clouds to form – in the troughs the air gets compressed and warms up, hence the clouds evaporate. Lenticular clouds are often called 'standing clouds' because they tend to remain in the same position relative to the mountains."
The images were also shared with the Highlandweather account on Twitter and joined a number of similar pictures posted online from across the far north where the phenomenon prevailed.
Highlandweather told the paper that the "fantastic formation of lenticular clouds" on Wednesday afternoon was caused by the strong SW winds blowing over the higher ground to the SW towards Wester Ross, Lochaber and Lochalsh.
"When the wind blows downstream of the higher ground lenticular clouds can form if the air collects enough moisture from the higher ground. They are typically very high in the sky sitting in the troposphere.
"The NE of Scotland is often one of the best places in the UK to see them due to the dominant wind direction being from the SW and the higher ground to our west."
The unusual cloud formations are relatively rare in this country and are believed to be one of the most common explanations for UFO sightings across the world.
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