The risk of landslides increases during the weekend in northern Norway
In Ofoten and Sør-Troms, the risk of avalanches increases to a great risk of avalanches (danger level 4) as temperature, wind and precipitation increase on Saturday. On Sunday, the risk of landslides increases to a great risk of landslides also in Svartisen, Salten, West Finnmark, North Troms, Lyngen and Inner Troms.
It is expected that many naturally occurring landslides can occur. Some landslides can be very large.
Increased risk of landslides in Ofoten and Sør-Troms on Saturday
The risk of landslides first increases in Ofoten and Sør-Troms beyond Saturday. The cause of the avalanche danger is a new low pressure with milder weather, significant rainfall and wind up to storm strength. Håvard Toft Larsen, duty manager in NVE’s avalanche warning, explains why this leads to extensive unstable conditions.
– In the mountains there is already a lot of fresh snow that has come in recent days. When it increases beyond Saturday, it will be possible for a lot of snow to accumulate on steep slopes over a short period of time, which increases the risk of landslides. An increase in temperature during the evening means that the snow cover is further destabilized. Mild weather and rain weaken the stability of the snow below the mild weather limit. Wet and dry luck landslides can loosen by themselves, and we expect some landslides to be very large.
Increased risk of landslides in northern Norway on Sunday
On Sunday, the risk of avalanches increases to great avalanche danger (danger level 4) also in Salten, Svartisen, West Finnmark, North Troms, Lyngen and Indre Troms. In all regions in the north, landslides can loosen by themselves on Sunday. Some very large landslides are also expected.
Mild weather, strong winds and increases the risk of landslides in northern Norway. In the mountains, it will be able to loosen large dry landslides because Finns move large amounts of jib snow into leheng, while it can loosen wet landslides in the lowlands because rain and mild weather weaken the snow, says Toft Larsen.
Mild weather and rain also lead to the danger of slush in Nordland and parts of Troms, and danger warnings have been issued at a good level. The risk of landslides will be greatest in areas where there is more than 50 cm of snow. Avalanches can be triggered on relatively gentle slopes where water is collected.
Mild weather increases the risk of wet landslides also in southern Norway
In Hardanger, Voss, Indre Fjordane, Sunnmøre, Romsdal, Trollheimen, Jotunheimen and Indre Sogn, the risk of landslides is significant. It is expected that some large wet landslides can loosen naturally. During the weekend, the mild weather limit rises, which means that wet landslides can loosen naturally higher up in the mountains. Håvard Toft Larsen, duty manager at NVE’s avalanche warning, says that people who are going on a trip should be careful.
– In general, we recommend avoiding terrain steeper than 30 degrees and keeping a good distance to outlet areas.