Norway, Sweden: Storm-related disruptions ongoing across the region as of Aug. 10 /update 1

Event

Disruptions are ongoing across parts of southern Norway and southern Sweden as of Aug. 10 due to the passing of Storm Hans through the region. The storm has brought heavy rainfall across the region since Aug. 7, causing many rivers to burst their banks, triggering widespread flooding. As of Aug. 10, authorities have evacuated more than 4,000 people across southern Norway due to flooding and landslides. The Braskereidfoss hydro-electric power plant on the Glama River in Innlandet County partially collapsed Aug. 9. All major roads in the region were closed as of early Aug. 10, and rail services across southern Norway have been suspended. A train derailed between Iggesund and Hudiksvall in eastern Sweden Aug. 7 during the storm, and much of the port of Gothenburg has been flooded.

Although weather conditions are expected to improve across the region from Aug. 10, the threat of flooding is likely to remain due to run-off from mountainous areas into already dangerously high rivers. As of Aug. 10, the Norwegian Meteorological Institute is maintaining red flood warnings (the highest level on a three tier-scale) for parts of southern Innlandet and central Viken counties, as well as orange and yellow flood warnings across Olso and much of the rest of Innlandet and Viken counties through at least Aug. 12. Yellow landslide warnings are also in place across parts of southern Norway. The Swedish Meteorological Institute is maintaining orange and yellow flood warnings across parts of far southern and south-central Sweden. 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 likely 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

MeteoAlarm
Norwegian Meteorological Institute
Swedish Meteorological and Hydrological Institute