Greatest probability of major spring floods will be in northern Norway

spring floodsRøykenes.Greatest probability of major spring floods will be in northern Norway. : Svein Eriksen / SCANPIX

Northern Norway will get the worst spring flooding this year, along with parts of Trøndelag and northern parts of eastern Norway. The rest the country, and southern Norway will escape, without paying a heavy price.

This is based upon net snowfall, and shown in an analysis made by the Norwegian Water Resources and Energy Directorate (NVE).

‘It is far more likely than normal for large scale spring flooding in the northern and central parts of the country. In large areas of southern Norway, the probability of major spring floods is extremely low based on what we know about snow there’, said a hydrologist and flood alert expert from NVE, Inger Karin Engen.

80% probability

In Northern Norway, there is as much as an 80% probability rating that spring floods may arrive on an orange level, the second highest level. These are floods of a magnitude that may cause serious injury. This applies especially to rivers that drain the Finnmark plateau, and some upland waterways in northern Norway.

Tana and Alta river, at Masi in Finnmark, has a 90% probability of a yellow warning level, and 70% of orange. Målselva in Troms was registered with an 80% probability that the flood risk may now be put at the orange level.

Compared to the last 56 years, the amounts of snow in early April is at around 90% of what is normal at this time of year for the country
as a whole.

‘This year there was unusually little snow in large parts of southern Norway, while there was very much snow compared to normal levels in northern parts of the country. In north eastern parts of Norway, it is quite normal to have snow at this time of year’, said Engen. She added that ‘therefore, the risk of major flooding in southern Norway is small, but will be conditional upon whether the weather gods agree’.

The weather since 1957

‘How big the floods really are, of course, is completely dependent on the weather. We have seen several examples in recent years of very large floods even though there has been little snow’, stressed Engen.

‘The analysis are based on current water storage, and the weather at this time of year since 1957. Then we calculate 59 theoretical flood scenarios. This forms the basis for our projections about the likelihood of major spring floods this year’, said Engen.


Source: NTB scanpix / Norway Today