Germany: Adverse weather forecast across south-central, southeastern, and western regions through at least early May 22

Heavy rainfall and thunderstorms are forecast across much of south-central, southeastern, and western Germany through at least early May 22. Heavy rainfall is expected in Saarland and parts of Rhineland-Palatinate states from early May 21 and severe thunderstorms are expected to break out across western, south-central, and southeastern regions from the afternoon of May 21 through early May 22. Rainfall totals of around 2-6 cm (1.2-0.8 inches) are expected across the region, with isolated higher totals, and winds gusting up to around 75 kph (47 mph) are possible during storms. As of May 20, the German Weather Service (DWD) has issued a red advance warning (the second highest level on a four-tier scale) for heavy rainfall across Saarland and parts of southern Rhineland-Palatinate and a red advance warning for severe thunderstorms across the rest of the affected area. Officials could update and extend the coverage of weather alerts over the coming hours and 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 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 are possible in hilly or mountainous areas, especially where heavy rain has saturated the soil.

Authorities could issue mandatory evacuation orders for flood-prone communities over the coming days. Disruptions to electricity and telecommunications services are possible where significant 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. Severe weather could also trigger flight delays and cancellations at regional airports. Flooding could block regional rail lines; freight and passenger train delays and cancelations are likely in areas with 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, possible evacuations, and some employees' inability to reach work sites.