Winter has receded in Europe this week. Temperature records are falling as unseasonably warm weather sweeps across the continent delivering an early spring thaw, even while neighbouring Russia is simultaneously going through a deep freeze.
The shocking weather pattern began to creep across the continent earlier this week, but has reached a fever pitch on Thursday as some countries’ all-time February high temperature records tumble. It was particularly balmy in Sweden on Thursday. An area in the country’s southeast recorded a high of 62.6 degrees Fahrenheit (17 degrees Celsius), the highest temperature in Sweden ever recorded in February. Though not the hottest temperature recorded in Europe, it’s jarring to see the mercury climb that high for a country synonymous with cold weather.
Poland also set an all-time record as did Lichtenstein, Croatia, Slovenia, and Slovakia, speaking to the widespread nature of the heat wave. Of those countries, Croatia saw the highest overall temperature, clocking in at nearly 80 degrees Fahrenheit (26.4 degrees Celsius). Fourteen monthly records for regions in the Czech Republic were also broken earlier this week. All told, temperatures are averaging anywhere from 20 to 30 degrees (11 to 16.7 degrees Celsius) above normal for this time of year.
The nice weather comes on the heels of an aggressive cold snap, sending residents yo-yoing from deep winter to spring in some areas over the course of a week. Germany recorded its biggest-ever boomerang from cold to warm temperatures, logging a low of minus-10.8 degrees Fahrenheit (minus-23.8 degrees Celsius( in the city of Goëttingen on Feb. 14 to a high of 64.6 degrees Fahrenheit (18.1 degrees Celsius) just seven days later. The previous record spike had been set in 1880. In addition to the heat over Europe right now, freakishly warm air is also parked in the Arctic near the North Pole as well as Greenland.
The warm temperatures are a little too familiar. In 2019, a heat wave swept the continent and delivered record-shattering temperatures in February of that year. The winter heat wave foretold a deadly hot summer, where around 2,500 people died due to excess heat. Researchers found the 2019 heat was at least 10 times more likely due to climate change, an increasingly common finding.
It’s not all balmy sunshiny weather this week, though. Temperature maps show an abrupt shift from warm to cold temperatures roughly dividing east and west portions of the continent. In Russia, temperatures plummeted 25 degrees Fahrenheit (13.9 degrees Celsius) below average in some regions.
The reason for the sharp divide between the two regions is a sharp snap in the jet stream, a fast-flowing river of air that travels from west to east. While it can wiggle here and there, every now in then the oscillations can become more extreme, trapping warm air from the tropics in one region and cold Arctic air in another. That’s exactly what’s happening over Europe and Russia respectively right now. Some research has linked extreme waves in the jet stream to increased Arctic warming, which is weakening the temperature gradient between the poles and tropics that normally holds the jet stream more taut. Outbreaks of more extreme temperatures are liable to become more common as a result, in addition to the impacts of other natural climate shifts that can sometimes align such as the Arctic Oscillation.
This week’s European warm wave should cool off a bit as we head into the weekend as a coming front helps break up the high pressure currently camped over the continent.