It happens every now and then. Today, on February 15, 2021 an unusually wide band of frigid air over the center of the United States is spreading dangerous ice and snow in many areas that rarely see such weather.
Utilities in 14 states are told to start rolling blackouts because of storm strains, reported the NYT. The National Weather Service that at least 150 million Americans were under ice or winter weather advisories. Many places have set record low temperatures, including 26 below zero in Sioux Falls, S.D. Hundreds more new daily records were expected to be set by the end of the week. As much as known now, the current cold spell will last for some more days.
Six years ago, in mid-February 2015 the situation was very similar. North American was caught by a cold wave that affected most of Canada and the eastern half of the United States. Several places broke their records for their coldest February on record, while some areas came very close. One of the explanation given was that the ‘Siberian Express’ pushed Arctic air and record lows to the United States, whereby decades-old cold records began to tumble in the Southeast, gripping the Midwest, Northeast, South, and four cities set all-time record lows (nbcnews.com reported on February 19, 2015)
In contrast to 2015, little has so far been heard of the ‘Siberia Express’ playing a role in the current cold snap. Wouldn’t it be interesting to know how it comes about and whether the North Atlantic and Europe also come into play? Was there a difference between 2015 and now in 2021?
Western Europe is under the influence of the weather system from West to East. Atlantic low pressure areas move east, unless cold continental high pressure air blocks them. These are the winters that Europe talks about.
This succeeds very well when the North Sea and Baltic do not assist the Atlantic weather because they cannot release enough heat or are hindered by sea icing. During last winter 2014/15 they served as perfect helpers and keep the cold from Siberia at a safe distance.
The more the Atlantic weather governs the situation beyond the Ural the further Polar and Siberian cold will be pushed eastwards, called ‘Siberian Express’. This was felt in Alaska, Canada and in the U.S.
This year Europe received a cold spell a few days earlier than the U.S, which receded today, the 15th February. The noticeable difference in the States currently is that the US Atlantic coast faces the severe cold spell in the next day, because the Atlantic and the still surplus average warm seas, could push the cold eastwards. Now the cold in North-America is stronger pushed towards the Atlantic, at least a bit which should not be ignored but the mechanism must be understood.
The subject in more detail at:: 1ocean-1climate