The weather in southern Europe has been crazy for weeks: winter storms keep causing severe weather with flooding and leaving behind extensive damage. The jet stream, which is currently meandering right over the Mediterranean, is to blame.

The jet stream, a band of strong winds in the atmosphere at an altitude of around 10 kilometres, normally directs low-pressure systems from the Atlantic across northern Europe, causing very changeable weather there, especially in the autumn and winter months.

This year, however, this weather-influencing band of strong winds is moving unusually far south, causing these lows to repeatedly sweep across Portugal, Spain and Italy and into the Aegean Sea.

Because the Mediterranean Sea is still warmer than average, it provides the approaching low-pressure systems with plenty of energy and thus perfect conditions for development. As a result, a storm front is even expected in Turkey, which is located far to the east, in the coming days.

Just on Wednesday, storm Kristin caused severe damage in Portugal. With peak gusts of up to 110 miles per hour, roofs were torn off and entire areas of forest were flattened. Hundreds of thousands of households were left without power and at least five people lost their lives.