The Norwegian Meteorological Institute has issued extreme weather warnings for Oppland, Hedmark, Buskerud, Hordaland, Sogn and Fjordane, Møre, Romsdal and Trøndelag.
In the coastal areas between Trøndelag and Hordaland, the storm may develop into a hurricane with wind gusts of up to 35 to 50 metres per second (108-180 kph).
The strong winds are expected to affect air travel.
“Worst case scenario, we will have to close airports. On the positive side, I note that we have had mild weather recently, so at least we don't have heavy snowfall to clear in addition to the wind,” Gurli Høeg Ulverud from airport operator Avinor told NTB.
SAS said on Friday morning that it anticipates flights will have difficulty landing at both Haugesund Karmøy Airport and Bergen Airport Flesland. Airports across Norway have advised travellers to stay updated on their airlines' websites.
Waves are expected to be as high as 13 metres outside of Hordaland and Sogn and Fjordane, leading to closed bridges and mountain passes. Ferry traffic may also be brought to a standstill.
“People should stay home and remain indoors [on Friday]. It will be dangerous. Bridges, ferry crossings and mountain passes may be closed. And then you'll be set in checkmate here in Western Norway,” Ronny Sleire, a traffic operator at the Road Traffic Management Centre West, told Bergens Tidende.
The extreme weather led Statoil to move some 250 employees to other platforms in the North Sea. Meanwhile, all helicopter departures from Bergen may also be cancelled.
The source of the extreme weather is a low pressure front that is expected to develop into a hurricane in the waters around Shetland. The system is expected to move into the northern part of the North Sea by Friday afternoon or evening before later hitting Western Norway and Trøndelag.
The Oslo area will get strong winds and precipitation on Friday, but nothing approaching the extremes that other parts of the country will see.
On Saturday, a somewhat weakened Tor will arrive in Nordland.