A high pressure zone stationed over Finland will ensure that conditions continue to be sunny but very cold throughout the weekend and beyond across much of the country. According to Meteorologist Marjo Hoikkanen, certain key factors are responsible for the current weather.
”We need sufficient cold air – an arctic air mass, which comes from Siberia or the North Pole. But cold air alone isn’t enough (to cause these conditions), we also need surface inversion,” Hoikkanen said.
Inversion causes cold air to settle very close to the ground surface, whereas in normal conditions temperatures fall as air rises. In clear, windless conditions the air does not circulate.
”The land surface freezes and cools all of the lower layers of air. Because the cold air is heavy, it remains close to ground level, it cannot circulate and mix. At worst it can continue for weeks at a time and the air just gets progressively colder,” Hoikkanen explained.
No change over the next week
As a result of the current conditions the cold snap will persist into next week. Precipitation will occur mainly in marine areas.
”Depending on wind direction snowfall will occur mainly closer to Sweden but last night and this morning (Saturday), it has arisen mostly on the south coast and to some extent also in the Åland Islands,” she added.
The mercury will inch down to -30 degrees Celsius in Lapland Saturday, while temperatures in the south will remain around -15 degrees, with no change in sight during the weekend.
“Looking ahead for about one week, there are no major changes on the horizon. Perhaps in the most frigid areas of Lapland, the -30-degree temperatures may let up a bit,” the meteorologist predicted.