Since Wednesday cold air from E. Europe has caused a decrease in temperatures along the peninsula, with values below the average (especially in central-southern Italy). The cold air, moving above the Adriatic sea, is causing snow on the eastern side of Italy, with more than 1 metre of snow in some areas on the Appennines (e.g. Capracotta in Molise). Some snow has reached also the coast (especially between Abruzzo and Puglia), with few centimetres on the beaches. Snow has also fallen in Sicily at low levels.
Meanwhile, in the north, bright conditions are occurring, with strong winds especially on the Alps, which have caused some wildfires between Veneto and Lombardia due to the very dry conditions (also some were caused by human activities).
Today has been the coldest of the year so far (and since the start of the winter in the south). In fact, both minimum and maximum temperatures are below the average mostly everywhere (Figure1). Negative values have been observed in the mainland along the peninsula, with peaks of -5/-8 °C on the Po Valley and Tuscany, and below -10 °C on the Alps. The maximum temperatures have been below 10 °C mostly everywhere, except in Liguria and Sardinia.
The interesting thing has been, as said previously, the snow along the coast of the Adriatic sea. This event is quite unusual (though it can happen every few years) and it is due to the Adriatic sea effect: very cold air (from the Balkans) moves above the warmer sea (picking up moisture), and pushes against the Appennines condensing and leading to precipitation. If the column of air is cold enough (like today), snow can fall also along the coast.
For this reason the snow observed today was significant, because the continuous flow of air from N.E. has led to precipitation on the same areas.
The situation is clearly visible from the satellite image (Figure2).
The cold air should move eastward tomorrow and by Sunday there will be an increase in temperatures especially in the south. Next week cold air from Central Europe should reach the peninsula, but it is still too early to describe the possible effects. In the meantime, we can enjoy this unusual weather in the south.