Weather, widespread rain and snowfall in the highlands today. From tomorrow, high pressure returns.

A new Atlantic-origin disturbance front is rapidly crossing Italy today, Saturday, November 7, bringing widespread precipitation, snowfall in the highlands, and a general increase in wind. The rain, of weak to moderate intensity, initially affected the Lombardy Alps and Pre-Alps and the regions of the Northeast, then extended in the afternoon to the central Adriatic side, and in the evening to Puglia, Basilicata, and Calabria. Snowfall is expected in the Dolomites at altitudes around 1,300-1,400 meters and in the northern Apennines from 1,600-1,800 meters.

Starting tomorrow, Sunday, November 8, a significant expansion of a high-pressure field is expected, ensuring ample clear skies and the restoration of atmospheric stability over much of the country. Residual rainfall, of weak intensity, will be confined only to Salento, the Ionian Calabria, and southeastern Sicily. During the night and early morning hours, fog banks may form over the low plains of the North and in the internal valleys of the Center.

Weather forecasts describe the passage of a 'disturbed front,' meaning an unstable air mass that, colliding with different air masses, brings weather changes. This specific front arrives from the Atlantic Ocean, an area often a source of disturbances for Europe. Its rapid passage over Italy is a typical event of the autumn season, when atmospheric currents favor the transit of cloud systems laden with rain from the northwest toward the southeast.

The mechanism predicts that, after the passage of a disturbed front, a period of stable weather often follows. This occurs because the front is followed by an area of 'high pressure,' also called an 'anticyclone,' where descending air tends to dissolve clouds and stabilize the atmosphere. The forecast of an improvement for tomorrow thus follows a classic meteorological dynamic: today's instability is caused by the front in transit, while tomorrow's stability is guaranteed by the arrival of this anticyclonic ridge. The nighttime fogs forecast in the North and Center are a direct consequence of the stabilization: with clear skies, the ground loses heat rapidly, cooling the air in contact and causing the water vapor present to condense.