A polar low pressure is a small, often intense low pressure that forms when cold air from the ice sheet in the Arctic flows out over open water, according to Store norske lexikon. These low pressures are often followed by heavy snow showers, strong winds and very poor driving conditions. And that is exactly what is heading towards Lofoten, Vesterålen and Troms right now. In a few hours it is expected to hit land – a bit unclear exactly where and when. They are therefore eagerly watching at the Meteorological Institute in Tromsø this afternoon. – Where this will end is difficult to say right now, meteorologist Gunnar Noer at Værvarslinga in northern Norway tells news. – We do not see anything related to the low pressure as such yet, other than heavy showers in the west of the sea off Lofoten, Vesterålen. And then we expect this to form in the evening and tonight. Photo: Meteorological Institute Polar low pressures in line Yr.no yesterday warned of severe weather when two polar low pressures hit the north early Thursday morning. – Polar low pressures often cause rapid changes in the weather. We have forecast a strong gale, but it is assumed that there may be a small storm. There is also a great deal of uncertainty in the forecasts now, so we formulate ourselves a bit. – What does the uncertainty consist of? – Firstly, whether the polar low pressures will form or not, and secondly, where they will be located. We now have two main solutions, one that provides the weather a bit out to sea, and one that provides weather around Vesterålen and Troms. The first polar low pressure is expected to form on the night of Thursday. And then more bad weather can roll in on Friday, mainly in Sør-Troms, Lofoten and Vesterålen, says the meteorologist. – It will lie slightly off the coast of Troms, if we are to believe the forecasts tomorrow. Then there is the development of new polar low pressure on Friday. There is a hint of development in Nordland on Saturday as well. Then it happens on Sunday. Polar low pressure Polar low pressures are small, intense low pressures that form in arctic air masses on the north side of the polar front in winter. In recent years, there have typically been 10–15 polar low pressures towards the Norwegian coast during the winter, and there are most cases in January to March. Experience shows that the wind can increase from a breeze to a gale in less than fifteen minutes. Polar low pressures are scary, as they bring rapid increases in wind and heavy snowfall, often with snow fronts and with difficult visibility and generally bad weather. In earlier times, polar low pressure was the cause of many shipwrecks and accidents, but in the period from 1999 to 2017 there is only one known case in Norway where life has been lost due to polar low pressure. Source: snl.no
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