Norway, Sweden: Flood-threat and disruptions continue in parts of the region following severe weather as of Aug. 15 /update 3

Event

Disruptions are ongoing across parts of southern Norway and southern and southeastern Sweden as of Aug. 15 following the passing of Storm Hans through the region. The storm brought heavy rainfall across the region Aug. 7-10, causing many rivers to burst their banks, triggering widespread flooding. Although floodwaters have begun to recede in many areas, the flood threat remains elevated and further rainfall is forecast in the region over the coming days, which could exacerbate the situation.

As of Aug. 15, more than 1,000 people remain evacuated across parts of southeastern Norway due to flooding and landslides. A railway bridge in Ringebu, Innlandet County, collapsed into the Lagen River Aug. 14. The Braskereidfoss hydro-electric power plant on the Glama River in Innlandet County partially collapsed Aug. 9. All major roads were closed and many rail services disrupted in the affected region following the passing of the storm. As of Aug. 15 all major routes have reopened; however, some minor roads remain closed and authorities are advising that lane closures and local diversions are ongoing in places. Sections of some rail lines remain closed and delays are possible on other routes. In Sweden, a train derailed between Iggesund and Hudiksvall in eastern Sweden Aug. 7 during the storm, and much of the port of Gothenburg was flooded. Severe flooding also occurred in Are Municipality in Jamtland County and several roads and rail services in affected areas were blocked by flooding and landslides.

As of Aug. 15, the Norwegian Meteorological Institute is maintaining red flood warnings (the highest level on a three tier-scale) for parts of Innlandet and Viken counties around the Drammen watercourse through at least Aug. 16. Orange flood warnings and orange and yellow landslide warnings are in place for other parts of Innlandet and Viken counties. A yellow rainfall warning is in place for parts of southeastern Norway late aug. 15-early Aug. 16. As of Aug. 15, the Swedish Meteorological Institute issued red flood warnings for areas along the Gavlean, Marnasan, and Kolningsan rivers through at least Aug. 18, as well as orange and yellow flood warnings across other parts of southern and southeastern Sweden. Yellow heavy rainfall warnings have been issued across parts of southern and southeastern Sweden late Aug. 15-early Aug. 16. Officials could update and extend the coverage of weather alerts over the coming days. Further heavy downpours could trigger additional flooding, especially in areas where river levels are already high and the ground is saturated from previous rainfall.

Hazardous Conditions
Further sustained heavy rainfall could trigger additional 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
Norwegian Public Roads Administration
Swedish Civil Contingencies Crisis Information