Norway, Sweden, Finland: Adverse weather forecast to continue across parts of Scandinavia through at least Jan. 15 in the aftermath of Storm Gyda /update 2

Event

Storm Gyda hit central and western Norway Jan. 12-13. Although the storm has been declared over, adverse weather is forecast to continue across much of Norway, northwestern Sweden, and southwestern Finland through at least Jan. 15. Gyda brought over 10 cm (4 inches) to much of central Norway and strong winds and snowfall, causing landslides, flooding, roads closures, and power outages across the region. Though the worst of the weather has passed and the Norwegian Meteorological Institute has declared the storm over, the threat of flooding, landslides, avalanches, and strong winds remain over the coming days.

Several roads have been closed due to flooding and landslides across the affected region, including in Gjemnes, Molde, Surnadal, Sunndal, and Volda municipalities in More og Romsdal County; Fosen, Garberg, Heim, Verdal, and Vinjeora municipalities in Trondelag County; in mountainous areas of Vestlandet County; and in the Saltfjellet mountain area of Nordland County. Many bus and ferry services in the affected areas have suspended operations. Hundreds of claims regarding minor property damage due to water inundation, roof damage, and leaks have been received by authorities across western and central Norway as of Jan. 14. Due to the storm, thousands of people were left without power across the country, including 8,200 in the Oslo area.

Government Advisories
As of Jan. 14, the Norwegian Meteorological Institute has issued red (the highest level on a three-tier scale) avalanche warnings for the Trollheimen mountain range in More og Romsdal and Trondelag counties; north and south Trondelag County; and Helgeland, Ofoten, Salten, and Svartisen in Nordland County. Orange avalanche warnings are in place across much of the rest of Norway. Yellow flood warnings are in place for More og Romsdal County and parts of Vestland and Trondelag counties. Yellow snow, landslide, avalanche, and wind warnings are in place for much of the rest of Norway.

Additionally, the Swedish Meteorological and Hydrological Institute has issued orange wind and snowfall warnings have been issued in the Lapland Mountains and mountainous areas of Jamtland County. Gale warnings have been issued for most eastern coastal areas of Sweden.

The Finish Meteorological Institute has issued orange warnings for strong winds and high waves for the seas off southwestern Finland Jan. 14-15. Yellow strong wind warnings have been issued for Aland, Satakunta, and Southwest Finland counties Jan. 14. Authorities could upgrade and expand coverage of the weather warnings over the coming days.

Hazardous Conditions
Flash and areal flooding are possible, especially in areas where the soil is saturated. Such flooding could occur in low-lying communities near watercourses and other bodies of water and in urban areas with easily overwhelmed stormwater drainage systems. Sites located downstream of large reservoirs may be subject to flash flooding after relatively short periods of intense rainfall. In addition to the heavy rainfall, the system will likely bring widespread damaging winds to coastal and mountainous areas. Wind gusts could cause blowing and drifting snow; decreased visibility is likely in mountainous areas. Rain-induced landslides cannot be discounted in areas of elevated terrain; there is also the possibility of avalanches in mountainous areas where the snowpack has become unstable due to heavy snowfall. Adverse weather conditions are likely to cause power outages throughout the affected area.

Transport
Storm Gyda will likely cause transport disruptions across affected areas through at least Jan. 15. Traffic and commercial trucking delays might occur along regional highways. Flooding downpours could inundate some low-lying roads in areas with poor drainage. Strong winds might also pose a hazard to high-profile vehicles. Floodwaters and related debris may render some bridges, rail networks, or roadways impassable, impacting overland travel in and around the affected area. Flooding in urban areas could also result in significant traffic congestion.

The disruptive weather will likely cause delays and cancellations at regional airports. Authorities may temporarily suspend port operations if strong winds trigger hazardous sea conditions, impacting freight and maritime passenger traffic. Flooding could block regional rail lines; freight and passenger train delays and cancellations are possible in areas that see heavy rainfall and potential track blockages.

Disruptions triggered by inclement weather and resultant hazards, such as flooding, could persist well after conditions have improved; it could take days before any floodwaters recede and/or debris is cleared. If there is severe damage to infrastructure, repair or reconstruction efforts may result in residual disruptions.

Advice

Monitor local media for weather-related updates and advisories. Confirm all transportation reservations and business arrangements prior to travel in the affected area. Seek updated information on road conditions before driving or routing shipments through areas where severe weather is forecast; plan for possible supply chain disruptions if routing shipments through affected areas. Stay away from elevated streams, creeks, and other watercourses that are prone to flash flooding. Do not attempt to navigate flooded roadways. Exercise caution in elevated terrain due to the threat of landslides. Charge battery-powered devices in the event of prolonged electricity outages.

Resources

MeteoAlarm
Norwegian Meteorological Institute (Norwegian)
Swedish Meteorological and Hydrological Institute (Swedish)
Finish Meteorological Institute (Finish)