Germany, Poland: Adverse weather forecast across the region through at least June 28

Severe weather is forecast across Germany and Poland through at least June 28. Thunderstorms are expected across parts of both countries over the coming days, with the most intense storms likely over parts of central and northern Germany and southern Poland June 27 and eastern and southern Germany June 28. Heavy rainfall, strong winds, lightning, and possible hail may accompany storms. 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 June 27, the German Weather Service (DWD) has issued a red advanced warning (the second highest level on a four-tier scale) of severe thunderstorms across parts of northern Bavaria, northeastern Hesse, central, eastern, and southeastern Lower Saxony, western Saxony-Anhalt, much of Schleswig-Holstein, central and western Thuringia states. Short-term red thunderstorm warnings are in place for parts of southwestern Saxony, as well as orange warnings for parts of southern and western Bavaria and yellow warnings for south-central Brandenburg states.

Poland's Institute of Meteorology and Water Management (IMGW) has issued orange thunderstorm warnings (the middle level on a three-tier scale) across Lesser Poland and much of Silesian, and parts of southern and eastern Holy Cross, southern Lodz, and southern Subcarpathian provinces. Yellow thunderstorm warnings are in place across Greater Poland, Lower Silesian, Lubusz, Opole, West Pomeranian, and the rest of Silesian provinces, as well as parts of southern and western Kuyavian-Pomeranian, southwestern and western Masovian, southwestern Pomeranian, and central and western Subcarpathian.

Officials could update and possibly 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 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 strong winds 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 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.