Germany, Poland: Adverse weather forecast across both countries through at least Aug. 28 /update 1

Event

Thunderstorms are forecast across parts of parts of Germany and Poland through at least Aug. 28. Heavy rainfall, strong winds, lightning, and possible hail may accompany storms. In Germany, storms are expected to spread from the west to the northeast Aug. 25, with further isolated storms in central and southern regions. Showers and thunderstorms are expected to continue in southeastern and northern regions Aug. 26-28, with isolated storms also possible across much of the country. Thunderstorms are possible across much of Poland Aug. 25-26, with the most severe storms likely in southern regions. Thunderstorms are likely to persist in southeastern regions Aug. 27-28, with showers possible across much of the rest of Poland. Heavy downpours could trigger flooding in low-lying areas and landslides on unstable slopes. Strong winds may cause property damage and power outages.

As of Aug. 25, the German Weather Service (DWD) has issued red short-term thunderstorm warnings (the second highest level on a four-tier scale) for parts of western North Rhine-Westphalia State, orange thunderstorm warnings for parts of northeastern and southeastern Baden-Wurttemberg, central, southern, and western Bavaria, northern Hesse, southeastern Lower Saxony, central, eastern, and western North Rhine-Westphalia, and far western Thuringia states, and yellow storm warnings for parts of western Thuringia State. A wider red-level advanced warning of severe thunderstorms is in place across a wide area stretching from western Germany across to northeastern regions. Rainfall amounts of up to 2.5 cm (1 inch) in a short period of time and winds gusting up to 110 kph (68 mph) are possible in parts of the affected area during storms.

Poland's Institute of Meteorology and Water Management (IMGW) has issued orange thunderstorms with hail warnings across Lower Silesia, Opole, and Silesia provinces and parts of central and western Lesser Poland and western Swietokrzyskie provinces. Yellow thunderstorms and hail warnings are in place across the rest of the eastern half of the country. Rainfall totals of 2.5-4 cm (1-1.6 inches) and winds gusting up to 90 kph (56 mph) are possible in affected areas.

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

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 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 rainfall 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.

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 airports in the region. Flooding could block regional rail lines; freight and passenger train delays and cancellations are possible 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, possible evacuations, 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. 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

Germany Weather Service (DWD)
Poland Institute of Meteorology and Water Management (IMGW)