Europe: Adverse weather forecast across northern Croatia, Hungary, Kosovo, and Serbia through at least June 23

Thunderstorms and heavy rainfall are forecast across northern Croatia, Hungary, Kosovo, and Serbia through at least June 23. Strong winds, lightning, and hail may accompany storms.

The Croatian Meteorological and Hydrological Service (DHMZ) issued orange thunderstorm warnings (the middle level on a three-tier scale) across Karlovac and Osijek regions and yellow thunderstorm warnings across Zagreb Region June 21. Orange thunderstorm warnings are in place for Osijek Region, and yellow thunderstorm warnings for Karlovac and Zagreb regions June 22.

The Hungarian Meteorological Service issued orange thunderstorm and yellow heavy rainfall warnings across central, eastern, and southern Hungary, and yellow thunderstorm warnings across the rest of the country June 22. Yellow thunderstorm warnings are in place across most of the country June 23, with the exception of some western regions.

The Republic Hydrometeorological Service of Serbia issued orange thunderstorm and yellow heavy rainfall warnings across Backa, Banat, and Srem regions and yellow thunderstorm warnings across Belgrade and Western Serbia regions June 22. Yellow thunderstorm warnings have been issued across Kosovo and Serbia June 23.

Officials could update and/or extend the coverage of weather alerts over the coming 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 cancellations are possible 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.