Norway, Sweden: Storm Gyda to bring heavy precipitation and possible flooding to Norway and northwestern and central Sweden through Jan. 14

Event

Storm Gyda is forecast to bring rounds of heavy precipitation, strong winds, and possible flooding to Norway and northwestern and central Sweden through at least Jan. 14.

Forecast models indicate extremely heavy rain in southern Trondelag and More og Romsdal counties in Norway Jan. 12-13. Significantly lower temperatures and a transition from rain to sleet and snow is likely in mountainous areas Jan. 14. Authorities warn that flooding, landslides, and avalanches are possible. Some uncertainty remains in the forecast and is subject to changes over the coming days.

Government Advisories
In response to Storm Gyda, the Norwegian Meteorological Institute has issued red (highest level on a three-tier scale) heavy rain warnings across southern Trondelag and More og Romsdal counties through Jan. 13. Orange heavy rain warnings are in place in Sogn og Fjordane and Innlandet while yellow heavy rain warnings have been issued over northern Trondelag and Hordaland. Yellow wind warnings are also in place off the coast of Trondelag and More og Romsdal early Jan. 12, while yellow snow and ice warnings are in place over the rest of northern and central Norway.

Additionally, the Swedish Meteorological and Hydrological Institute has issued orange wind and snowfall warnings in the Lapland Mountains through Jan. 14. Yellow ice warnings are in place across Angermanland as well as Jamtland, southeastern Norrbotten, and Vasterbotten counties. Authorities could upgrade and expand coverage of the weather warnings over the coming days.

Hazardous Conditions
Flash and areal flooding is possible, especially in areas where the soil is saturated. Such flooding could occur in low-lying communities near watercourses and other bodies of water, as well as 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. Rain-induced landslides cannot be discounted in areas of elevated terrain. In addition to the heavy rainfall, the system will likely bring widespread damaging winds to coastal and mountainous areas. The 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. 14. 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)