The powerful “Greenland Block” increases the chances of extreme weather | Bot To News


A man hauls out cars after a snow storm in February 2010 in Silver Spring, Maryland.

A man uses a shovel to dig up his car in Silver Spring, Maryland, on February 6, 2010. Photo: Jewel Samad/AFP via Getty Images

An extreme weather pattern is affecting conditions in the US and Europe, specifically in a powerful area of ​​high pressure in Greenland and Hudson Bay. This feature, known as the “Greenland Block,” along with another climate cycle, typically leads to cold and snowy in the eastern United States, parts of Europe and Asia.

The panorama: The lockdown high in Greenland is acting as an atmospheric bypass, shifting weather systems around it and encouraging, but not guaranteeing, bouts of cold air in Europe and North America as Christmas approaches.

  • In the UK, temperatures dipped below freezing in many areas on Wednesday with unusually cold conditions. it is expected to last until the weekend and next week.
  • The UK Met Office is forecasting snow, ice and in some places blizzard conditions for parts of Scotland, Ireland and Wales.
  • This could cause energy prices to rise sharply after the winter has gotten off to a mild start, due to gas supply shortages due to the war in Ukraine.

meanwhile in the arctictemperatures have been much milder than average despite 24 hours of darkness.

  • On Sunday, Utqiagvik, the northernmost community in the US, experienced its warmest day in December on record, with a high of 4°F. This was also the warmest day there between October 20 and April 22, according to the National Weather Service.
  • Greenland, which lies under the high pressure dome, has also recently seen unusually mild conditions. Due mainly to human-caused climate change, the Arctic has been warming at about four times the rate of the rest of the world.

Between lines: Meanwhile, conditions over the North Atlantic are reminiscent of the blizzard-induced pattern during the winter of 2009-10, when blizzards “Snowmageddon” and “Snowpocalypse” buried the Mid-Atlantic states.

  • However, there is no guarantee that this pattern will have the same result, the experts told Axios. In fact, signs so far indicate that it could even lead to milder-than-average conditions in the central and eastern US over the next week or two.
  • The North Atlantic Oscillation, which is the cycle of air pressure variability over the center of the North Atlantic Ocean, it currently also favors outbreaks of cold air and snow for parts of North America, Europe and Asia. The NAO index is calculated by taking the difference in air pressure at sea level between Iceland and the Azores.
  • The last time the NAO was this negative during the month of December was in 2009, according to Judah Cohen, AER’s head of seasonal forecasting.
  • Cohen told Axios that the NAO is a big driver of colder-than-average conditions in Europe and often does the same in the eastern US.
  • Some of the biggest snowstorms in cities like Washington, New York, and Boston were tied to NAO negative phases.
Computer model projection showing the Greenland block in place, influencing the northern hemisphere weather pattern.
Computer model projection showing the Greenland block in place, influencing the northern hemisphere weather pattern. (Weatherbell.com)

How does it work: During periods of Greenland lockdown and negative NAO conditions, the jet stream blowing west to east across the US is often forced south, preventing storms from moving west from the I-95 corridor and bring warm air and rain.

  • Instead, these factors increase the chances of cooler coastal storms that tend to be more likely to be prolific snow producers.
  • “I think there’s a strong chance that this pattern will produce something memorable,” Cohen said, noting that computer model projections don’t yet show such a scenario.

the intrigue: According to University of Oklahoma meteorologist Tomer Burg, subtle differences between the current weather pattern and past Greenland blocking events can make all the difference in this case.

  • Instead of blocking and allowing frigid air to invade Europe and the US immediately, computer models show the likely development of a powerful storm system in the central US Rocky Mountains.
  • Meanwhile, the East could experience a period of unusual warmth. This storm could, in time, allow cold air to move eastward at the end of the month.

The bottom line: Extreme weather patterns often result in remarkable results, even if they don’t fit the textbook definition of a particular phenomenon.





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