France: Adverse weather forecast across much of the country through at least Sept. 13

Event

Severe weather is forecast across much of mainland France through at least Sept. 13. Thunderstorms are forecast to break out across parts of the country as the recent heatwave impacting much of France draws to a close. Storms are expected to impact southeastern, eastern, central, and northern regions Sept. 11-12, before shifting eastward through Sept. 13. Winds gusting up to 90 mph (56 kph) and rainfall totals of 3 cm (1.2 inches) per hour are possible during storms. Heavy downpours associated with the storms could trigger flooding in low-lying areas. Strong winds, lightning, and possible hail may also accompany storms.

Meteo France has issued the following weather warnings across the country Sept. 11:

• Orange thunderstorm warnings (the middle tier on a three-tier scale): Dordogne, Gironde, Landes, Lot-et-Garonne, and Pyrenees-Atlantiques departments in Nouvelle Aquitaine Region and Gers, Hautes-Pyrenees, Lot, and Tarn-et Garonne departments in Occitanie Region.

• Yellow thunderstorm warnings: Across the rest of Nouvelle Aquitaine Region, all of Centre-Val de Loire, Hauts-de-France, Ile-de-France, Normandy, and Pays de la Loire regions and Nievre and Yonne departments in Bourgogne-Franche-Comte Region, Ille-et-Vilaine Department in Brittany Region, Ardennes, Aube, Marne, and Meuse departments in Grand Est Region, and Aveyron, Haute-Garonne, and Tarn departments in Occitanie Region.

Further yellow thunderstorm warnings have been issued across much of central, eastern, northeastern, and southern France Sept, 12. Officials could update and possibly extend the coverage of weather alerts over the coming days.

Hazardous Conditions
The storms could produce rounds of heavy precipitation, strong winds, and isolated thunderstorm activity in affected areas. Where precipitation falls as rain, flash and areal flooding is possible. Such flooding is possible in low-lying communities near watercourses and other large bodies of water, as well as in urban areas with easily overwhelmed stormwater drainage systems. Sites downstream of large reservoirs may be subject to flash flooding after relatively short periods of intense rainfall. Power outages could occur throughout the affected areas due to potential wind damage to power lines and other infrastructure.

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.

The disruptive weather may cause some delays and cancellations at airports in the worst affected areas. Flooding could block regional rail lines; freight and passenger train delays and cancellations are possible in areas that see heavy rainfall and potential track blockages.

Disruptions triggered by inclement weather and resultant hazards, such as flooding, could persist well after conditions have improved - it could take days before any floodwaters recede and/or officials clear debris. If there is severe damage to infrastructure, repair and/or reconstruction efforts may result in residual disruptions.

Advice

Monitor local media for weather-related updates and advisories. Confirm all transport reservations and business arrangements before traveling in affected areas. Seek updated information on road conditions before driving or routing shipments through areas where severe weather is forecast; plan for possible supply chain disruptions throughout the affected areas. Stay away from elevated streams, creeks, and other watercourses that are prone to flash flooding. Do not attempt to navigate flooded roadways. Exercise caution in elevated terrain due to the threat of landslides. Charge battery-powered devices in the case of prolonged electricity outages.

Resources

Meteo France