Blocking Patterns: Cool Air Down South Means a Heatwave in Greenland

Global warming has mangled the Northern hemisphere’s weather. No clearer indication of this is the fact that currently, where I’m sitting in Gaithersburg, MD it’s 48 degrees Fahrenheit. Now let’s jump northward. Way north. North of the Arctic Circle north. So far north that only tens of miles away rests a glacier hundreds of meters thick.

That’s right, we’re talking about Greenland. Nuuk, Greenland to be specific. What’s the temperature there currently at 3:51 PM, Gaithersburg time?

48 degrees Fahrenheit.

The fact that two places separated so far north and south can experience practically the same weather is a perfect illustration of what global warming combined with Arctic sea ice melt has done to our weather patterns. Currently, a powerful blocking pattern and a very wavy jet stream is plunging far to the south and into the eastern United States. That jet stream has origins in the Arctic, so it is currently involved in cooling down Gaithersburg, Maryland.

The jet currently running down over the eastern US drinks deep of warmer temperate and tropical air before making a hairpin turn to the north, it travels up over the Atlantic Ocean, keeps making its way north until, at last, it comes to Greenland, depositing 48 degree Gaitherburg air directly over where it should be freezing in Nuuk.

That 48 degree temperature is a veritable heatwave for Nuuk at this time of year. The average daily high for this date is 26 degrees Fahrenheit. Nuuk’s high for today is 22 degrees warmer than it should be. And it’s not just today. For much of the winter Greenland has been far, far hotter than usual. The below graph, provided by NSIDC shows average temperatures for the Nuuk region of Greenland being about 5 degrees Fahrenheit or 3.3 degrees Celsius above average for the entire period.

Greenland temps NSIDC

(Image source: NSIDC)

Persistent warmer temperatures for Greenland have been a typical result of the new, global warming spawned weather pattern. It is this weather pattern that resulted in a major melt event for Greenland last summer. One that wrecked infrastructure there and contributed mightily to a 1 cm rise in sea level in just one year. Well, that blocking pattern is still in place. Going into the spring/summer of 2013, the weather is still stuck in a much hotter than usual mode for Greenland. If it continues, it will likely mean both more glacial melt and more extreme weather.

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