Italy: Adverse weather forecast across much of the country through at least Nov. 23

Successive weather systems are expected to bring rainfall, thunderstorms, snowfall, and strong winds across parts of Italy through at least Nov. 23. The first system is expected to bring showers, storms, and strong winds to central and southern regions and some snowfall in northern Alpine regions Nov. 20, before a second more intense system generates rainfall and strong winds across much of the country and snowfall at lower altitudes in northern regions Nov. 21-22, as well as a drop in temperature particularly across northern Italy. Conditions are forecast to improve in most areas from Nov. 23. Heavy rainfall may trigger flooding in low-lying areas and landslides on unstable slopes. Strong winds may cause property damage and power outages. Hazardous travel conditions are likely in mountainous regions due to reduced visibility caused by blowing snow.

Officials have issued the following weather warnings across the country Nov. 20-21:

Nov. 20

• Orange strong wind warnings (the middle level on a three-tier scale): Abruzzo, Aosta Valley, Basilicata, Calabria, Campania, Emilia-Romagna, Lazio, Marche, Molise, Puglia, Sardinia, Sicily, Tuscany, and Umbria regions.

• Yellow heavy rainfall warnings: Tuscany Region.

• Yellow thunderstorm warnings: Basilicata, Calabria, Campania, Sicily, Tuscany, and Umbria regions.

• Yellow snowfall warnings: Aosta Valley Region.

• Yellow strong wind warnings: Trentino Alto Adige Region.

Nov. 21

• Orange heavy rainfall warnings: Tuscany Region.

• Orange heavy snowfall warnings: Aosta Valley, Emilia-Romagna, Liguria, Piedmont, and Tuscany regions.

• Orange strong wind warnings: Abruzzo, Lazio, Liguria, Marche, Molise, Puglia, Sardinia, Sicily, Tuscany, and Umbria regions.

• Yellow thunderstorm warnings: Calabria, Campania, Lazio, Sicily, and Tuscany regions.

• Yellow snowfall warnings: Friuli Venezia Giulia, Lombardy, Trentino Alto Adige, and Veneto regions.

• Yellow strong wind warnings: Aosta Valley, Basilicata, Campania, Friuli Venezia Giulia, Piedmont, and Veneto regions.

Officials could update and possibly extend the coverage of weather alerts over the coming days.

Sustained heavy rainfall could trigger flooding in low-lying communities near rivers, streams, and creeks. Urban flooding is also possible in developed areas with easily overwhelmed or a lack of stormwater drainage systems. Sites located downstream from large reservoirs or rivers may be subject to flash flooding after relatively short periods of intense rainfall.

Precipitation could fall as snow in the higher elevations over the coming days. Wind gusts could cause blowing and drifting snow; decreased visibility is likely in mountainous areas. Rain-induced landslides cannot be discounted in areas of elevated terrain; there is also the possibility of avalanches in mountainous areas where the snowpack has become unstable due to heavy snowfall. Disruptions to electricity and telecommunications services are possible where significant winds, flooding, or landslides impact utility networks.

Floodwaters and debris flows may render some bridges, rail networks, or roadways impassable, impacting overland travel in and around affected areas. Ponding on road surfaces could cause hazardous driving conditions on regional highways. Authorities could temporarily close some low-lying routes that become inundated by floodwaters. Heavy snow will likely make driving hazardous in some areas; authorities could implement temporary road closures or detours in such locations. Mountain passes and tunnels could be closed as a precautionary measure during periods of intense snowfall.

The disruptive weather will likely cause delays and cancellations at regional airports. Authorities may temporarily suspend port operations along the coast if strong winds trigger hazardous sea conditions, impacting freight and passenger maritime traffic. Flooding or snow could block regional rail lines; freight and passenger train delays and cancellations are possible in areas that see heavy rainfall and potential track blockages.