Gale force winds were reported on land, and at sea wind speeds as high as 27 metres a second were expected. High speed passenger vessels operating between Helsinki and Tallinn remained in port already on Wednesday.

Emergency services braced themselves for extra work Wednesday evening, and electric utilities were prepared to deal with electric blackouts.

Conditions should be less severe on Thursday, when much of the holiday traffic is expected to take place.

Wednesday night's storm is expected to be followed by a low pressure area bringing widespread precipitation around the country. Most of Finland is set to get a blanket of snow by Christmas, with the exception of the southwest, where rain could predominate.

The Finnish Environment Centre warns that the heavy rain could lead to flooding in southern and south-western waterways at around Christmas and New Year.

The flow of water in many rivers is already unusually strong, and water levels are higher than normal, following recent heavy rains. The situation was exacerbated by Wednesday night's storm, and further rain forecast for the week after Christmas could cause considerable winter flooding.

The low pressure systems are to be interspersed with bouts of cold weather, leading to the additional risk of freezing flood water.