Heavy snowfall in the mountains of northern Greece caused severe transport problems yesterday, while schools were closed for the day in the town of Kastoria and in the Kozani area. Meanwhile, high winds in the Aegean prompted a ban on ferry sailings from the port of Piraeus, while the only ships allowed to leave Rafina were ferries making the short crossing to Marmari in Evia. Dozens of vehicles were caught in snow over a meter deep in the Katara mountain pass in northern Greece. A coach full of people who had traveled north to vote in the elections had to be evacuated. All vehicles using mountain roads in the prefectures of Grevena, Florina, Kastoria and Imathia needed snow chains. The weather is expected to improve today and tomorrow, before taking a new turn for the worse on Friday.