Norway: Adverse weather forecast across northern regions through at least Dec. 10

Severe weather is forecast across parts of northern Norway through at least Dec. 10. Heavy rainfall and strong winds are forecast across parts of Nordland, Troms, Finnmark, and northern Trondelag counties, with rainfall totals of 5-9 cm (2-3.5 inches) possible in parts of the region Dec. 9-10. precipitation is expected to gradually transition to sleet or snow late Dec. 10. The heavy downpours could trigger flooding in low-lying areas and landslides on unstable slopes. Avalanches are also possible in mountainous areas due to loosened snowpack.

As of Dec. 9, the Norwegian Meteorological Institute has issued orange heavy rainfall warnings (the middle level on a three-tier scale) for parts of Nordland, Troms, and western Finnmark counties and yellow heavy rainfall warnings for other parts of Nordland and Finnmark counties. Yellow strong wind warnings are in place for parts of northern Troms and western Finnmark counties. Orange and yellow flood and landslide warnings are in place over much of the affected area. Red high avalanche danger warnings have been issued for the Lyngen area in northern Troms County Dec. 10 and orange and yellow avalanche warnings are in place across the region Dec. 9-10. Officials could update and possibly 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 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.

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.