Norway: Adverse weather forecast across southern regions through at least Nov. 26

Event

Heavy rainfall is forecast to bring a threat of flooding and landslides across parts of southern Norway through at least Nov. 26. The affected area includes southern parts of Agder and Vestfold og Telemark counties along the Skagerrak Strait coast. The heavy downpours could cause rivers to overflow and lead to flooding in low-lying areas, as well as landslides on unstable slopes. Floodwaters on road surfaces will likely cause transport disruptions in the affected area; road closures have been reported in Arendal in Agder County and Brodsjovannet in Vestfold og Telemark Nov. 25.

As of Nov. 25, the Norwegian Meteorological Institute has issued the following weather warnings across the affected area:

• Orange flood warnings (the middle level on a three-tier scale): Across parts of southeastern Agder and southwestern Vestfold og Telemark counties.

• Yellow flood and landslide warnings: Across the rest of the affected area.

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 and 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 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 affected regions. 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

Norwegian Meteorological Institute