Denmark: Adverse weather forecast across most of the country through early June 28

Severe weather is forecast across most of Denmark through early June 28. Thunderstorms and heavy rainfall are expected to move in from the south into southern Jutland late afternoon June 27. The unstable weather is expected to spread over much of the country overnight June 27-28, but will likely lose intensity as it moves northeastward over the country. Rainfall amounts of 2.5-3.5 cm (1-1.4 inches) in less than an hour are possible during storms in southern regions and 1.5-2.5 (0.6-1 inches) in eastern and northern regions. Heavy downpours may trigger flooding in low-lying areas and strong winds may cause property damage and power outages.

As of June 27, the Danish Meteorological Institute has issued orange thunderstorm, heavy rainfall, and hail warnings (the highest level on a three-tier scale) across the Jutland area of Syddanmark and central and western Midtjylland regions. Yellow warnings are in place for the rest of Syddanmark and Midtjylland regions and parts of southwestern Nordjylland and southern Sjaelland regions. Blue warnings are in place across the rest of the country, with the exception of Bornholm Island. Authorities will likely issue new alerts or update/rescind existing advisories as weather conditions change over the coming days.

The storms could produce rounds of heavy rainfall, strong winds, and isolated thunderstorm activity across the affected areas. 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 the soil has become saturated by heavy rainfall.

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, landslides, 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. Strong winds might also pose a hazard to high-profile vehicles.

Severe weather could also trigger flight delays and cancellations at airports across the affected areas. Authorities may temporarily suspend port operations or close beach fronts if strong winds trigger hazardous sea conditions. 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.