The weather in the Northern Baltic is colder than average. The winds have been blowing from the northwest and have been quite strong. This has meant that the remaining ice is packed to the Eastern end of the Gulf of Finland making it very difficult for ships traveling to and from the Russian ports.
A week ago I saw a ship stuck on ice a little west from Helsinki while traveling on a ferry to Stockholm. The situation today is much better in the western parts of the Gulf.
The Finnish Meterological institute uses three categories to classify the ice season in the Baltic: severe, normal and mild. This assessment is only based on the ice coverage and it doesn't take into account the type of ice. This winter has been classified as "severe".
Normally the new ice is formed during the cold periods. Things get bad for the maritime traffic when the weather warms and the winds start blowing. The winds cause the formation of ridged or hummocked ice, which is the most difficult for the ships and icebreakers alike.
Currently, the weather is colder than average and there is still a lot of 'global warming' on the ground. This winter has been compared to the very cold winter of 1986/87 and the comparison is justified, since there have been long periods of freezing weather though not such extremely cold temperatures as in 1987.
The pictures in this page
show the ice coverage in different winters. In 1987 almost the entire Baltic sea including the straits of Denmark had ice cover.