Europe: Adverse weather forecast across southeastern France, western Italy, Monaco, far eastern Spain, and southern Switzerland through Oct. 6 /update 1

Event

Rounds of thunderstorms, heavy rainfall, strong winds, and possible flooding are forecast to occur in Southeastern France, western Italy, Monaco, the Balearic Islands in Spain, and western and central Switzerland through at least Oct. 6.

Authorities have issued the following warnings:

• Red-level heavy rain, thunderstorm, and flood warnings (the highest level on a four-tier scale): Bouches du Rhone Department in France; Liguria, Piedmont, and Tuscany regions in Italy; far western Grisons, northwestern Ticino, and Uri cantons in Switzerland

• Orange-level heavy rain, thunderstorm, and flood warnings (second-highest level on a four-tier scale): Alpes de Haute Provence, Alpes Maritimes, Haute Corse, Var, and Vaucluse departments in France; Aosta Valley, Lazio, Lombardy, Sardinia, and Sicily regions in Italy; Monaco; the Balearic Islands in Spain; far southeastern Bern, Glarus, western Grisons, Nidwalden, Obwalden, Schwyz, northern Ticino, and eastern Valais cantons in Switzerland

• Yellow-level warnings: The rest of the affected area

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

Hazardous Conditions
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. Landslides cannot be discounted in hilly or mountainous areas, especially where the soil has become saturated by heavy rainfall. Disruptions to electricity and telecommunications services are possible where significant winds, flooding, or landslides impact utility networks.

Transport
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.

Severe weather could also trigger flight delays and cancellations at regional airports. Flooding could block regional rail lines; freight and passenger train delays and cancellations are likely in areas that see heavy rainfall and potential track inundation.

Localized business disruptions may occur in low-lying areas; some businesses might not operate at full capacity because of flood damage to facilities and some employees' inability to reach work sites.

Advice

Monitor local media for weather updates and related advisories. Confirm all transport reservations and business appointments before travel through at least Oct. 6. Make allowances for localized travel delays and potential supply chain disruptions where flooding has been forecast. Do not drive on flooded roads. Charge battery-powered devices in the case of prolonged electricity outages.

Resources

MeteoAlarm
Météo-France (French)
Italy Servizio Meteorologico (Italian)
Spain Agencia Estatal de Meteorologia (Spanish)
MeteoSwiss (German)