Severe weather approaching Northern Italy: Atlantic disturbance brings heavy rains

An Atlantic disturbance is preparing to hit Italy, bringing bad weather to several regions, particularly in the North. Starting Wednesday, September 16th, the stable weather of recent days will be disrupted by the arrival of an unstable trough from the North Atlantic. The first rains will affect the northern regions, with more widespread and intense phenomena in the Alps and central-northern Lombardy.

Thursday, September 17th is expected to be the most unstable phase, with widespread and strong showers and thunderstorms in central Liguria, central-eastern Piedmont, Lombardy (especially Milan, Bergamo, Brescia), western Emilia, and particularly in the areas of Trevigiano, northeastern Veneziano, and Friuli Venezia Giulia. Here, rainfall accumulations could be more substantial, with a risk of critical conditions. Phenomena will also affect much of Tuscany and Umbria.

On Friday the 18th, the bad weather will persist in the North in a more irregular form, improving from the Northwest in the afternoon-evening. Temperatures will see a moderate rise due to the influx of mild western currents. The Central-South and the islands will generally experience better conditions, with scarce or localized phenomena.

The arrival of this disturbance follows a period of meteorological stability over Italy, after the passage of an unstable wave in the middle of last week. Until today, with the exception of Sicily and southern Calabria affected by a cyclone over the southern Mediterranean, the weather has been substantially dry and sunny over the rest of the country. The moderate stability was due to a recovery of high pressure, more structured in the west.

The situation is changing due to a new plunge of an unstable trough from the North Atlantic, which will already move close to the Alpine sectors tomorrow. A depressionary trough extending from Scandinavia to the Baltic will orient itself toward France and central-eastern Spain, activating humid and unstable currents that from the western Mediterranean will conquer northern Italy. This meteorological mechanism causes the disturbance to extend progressively.

Projections indicate that after this bad weather episode, between the end of the week and the last decade of September, high pressure may strengthen again, with good weather and temperatures still above the seasonal average. The summer of 2026 has already recorded the record for the hottest season in Italy since 1950, and the long-term projections from the European Centre for Medium-Range Weather Forecasts foresee a dynamic climate with possible new unstable episodes alternating with mild or warm phases.