Bad weather on the way: heavy downpours expected in the Northwest over the weekend

An intense weather disturbance is set to hit northwestern Italy over the weekend. According to forecasts, a cold air vortex of Baltic origin, moving retrogressively towards Western Europe, will cause a worsening of the weather starting Saturday evening, with rains intensifying on Sunday.

The most affected regions will be Piedmont and Liguria, where showers and thunderstorms are expected, locally heavy and persistent, with torrential downpour characteristics. Weather models estimate rainfall accumulations that could exceed 200 millimeters in 24 hours, especially in northern Piedmont, eastern Liguria, and upper Tuscany. The bad weather will also involve western Lombardy and western Emilia, but with less intense phenomena.

In Central Italy, showers and thunderstorms will affect Tuscany and upper Lazio, while in the South, irregular cloudiness with some rain is expected in Ionian Sicily and southern Calabria. Over the rest of the country, the weather will be more stable, with widespread clearings along the Adriatic and in Central-Southern Italy.

The weather forecasting and alert system in Italy for civil protection purposes operates differently from ordinary weather forecasts. The National Department of Civil Protection, together with the Regions, prepares the National Meteorological Vigilance Bulletin daily, which highlights potentially dangerous situations for people or property. This bulletin serves as the basis for assessing hydrogeological risks such as flooding and landslides.

Based on these forecasts, each Region and Autonomous Province evaluates potential criticalities in their territory and communicates them in the National Criticality/Alert Bulletin. It is then the responsibility of the Regions to disseminate alerts to local civil protection systems. Finally, Mayors are tasked with activating municipal plans, informing citizens, and deciding on actions to protect the population in the event of severe weather.

The incoming event was identified by probabilistic models over a week ago. Its dynamics are unusual: it is not a classic Atlantic depression, but a core of cold air detached from the Baltic latitudes. This vortex, pushed toward France, will interact with milder, humid air, while a blocking anticyclone over the central Mediterranean will favor the persistence of heavy rainfall in northwestern Italian regions.