A low pressure system underwent what is known as "explosive cyclogenesis" - or less formally became a "weather bomb" - when it intensified rapidly with a steep decline in pressure, between Greenland and Iceland late on Monday and early on Tuesday.
The system has brought strong wind to Iceland and to the United Kingdom and Ireland, with particularly high waves on the open sea. The waves were described as "phenomenal" in the shipping forecast for the Rockall area.
The low pressure system, known in some countries as Alexandra, has also brought strong wind to northern areas of mainland Europe.
