The phenomenon is described in meteorological jargon as the North Atlantic oscillation is entering a negative phase (NAO)
Prior to last winter the phenomenon had not occurred for years, with the standard situation being that NAO was in a positive phase with warm southwesterly winds bringing mild, almost snow-free winters to northern Europe.
“It is now looking exactly like last winter. If it continues it means the cold. But you never know when it turns,” said meteorologist and researchers Per Kållberg at meteorological agency SMHI to the Sydsvenskan daily.
Meteorologists across the globe are now discussing whether the negative phase will persist. It started in December 2009 and has remained since then, which is the longest period for 40 years, according to the newspaper.
“The fascinating thing is that we have known about this phenomenon a long time but have no idea why it emerges,” said Per Kållberg.
Temperatures plunged across Sweden on Wednesday night at the same time as wind and snowfalls in southern Sweden started to ease off.
Nikkaluokta in northern Lapland recorded -36 degrees Celsius during Wednesday – the lowest temperature so far this winter, according to SMHI. It is furthermore the lowest November temperature in Sweden since 1995, when -37 degrees Celsius was recorded in Vuoggatjålme in central Lapland.
The extremely cold temperatures are forecast to hold until at least over the weekend, according to SMHI.
SMHI retained a class 2 storm warning, the next highest level, for high water levels in Ljungbyån and Lyckebyån.
Snowfalls continue to cause slippery conditions on many roads in southern and central Sweden.
An accident involving a truck and post office vehicle was reported in Kalmar county, but no injuries were sustained.
“It is icy in the whole county,” said a spokesperson for the county police force.
Two people were injured in a collision between a bus and a car on road 28 between Nävragöl and Spjutsbygd north of Karlskrona during the morning.
They were rushed to Blekinge hospital in Karlskrona, with their condition unknown on Thursday morning.
A school bus landed in the ditch in Lilla Edet and came to a rest on its side. No one was hurt in the accident.