Potential flooding has been compared to famous July 1995 floods in Eastern Norway, which itself was the worst flood in the region since the 18th century.
Sudden melting of snow during warmer weather caused the 1995 flood, which is estimated to have cost Norway two billion kroner.
Similar conditions in 2018 were predicted by meteorologists as early as March this year, NRK reports.
“There is every reason to be wary of the situation, which is like that of 1995 with a lot of snow in the mountains and a long cold spell. If it suddenly gets warm with a lot of rain, conditions are optimal for a similar spring flood,” climate researcher Øyvind Paasche of the Bjerknes Centre for Climate Research told the broadcaster.
Water levels in several rivers in Eastern Norway are now reported to be on the rise as a result of warm spring weather.
Professor Atle Nesje of the University of Bergen's Department of Earth Science told NRK that water levels were likely to rise in coming days.
“There is a lot of snow melting caused by high daytime temperatures, and high levels of precipitation are expected in the coming days. That increases risk of flooding in Eastern Norway,” he said.
Weather warning information service varsom.no currently rates flood risk levels as “orange” – the third of five warning levels – for the Buskerud, Oppland and Hedmark counties.
That denotes a “serious situation that occurs rarely, requires preparation by response teams and can cause serious damage,” according to the website, a collaboration between the Norwegian Water Resources and Energy Directorate (NVE), Norwegian Meteorological Institute (MET) and The Norwegian Public Roads Administration (NPRA)
Residents are advised by the agency to keep updated on the situation by following weather and radar reports and updates. Valuable items should be moved from at-risk areas such as low-lying valleys as well as basements. Drainage routes should be kept open and access roads free from any remaining ice and snow as well as other obstructions.
“What has characterised conditions this year has been relatively high snow levels in the valleys of Eastern Norway, combined with the late spring, which raises concerns of flooding when warm weather combines with rain. That is exactly what we will have in the next two to three days,” Nesje told NRK.