It has been a chilly March across much of the Northern Hemisphere, due to a blocking high pressure system that was stalled over Greenland. Climate Central explains:
As Climate Central has reported, the long-lasting cold was related to a strong blocking High pressure system over Greenland, which was associated with a particular configuration of an atmospheric pressure pattern known as the Arctic Oscillation, or AO. The AO is a measure of the difference in relative air pressure between the Arctic and the mid-latitudes, and the configuration of air pressure patterns can have profound impacts on weather patterns in the Northern Hemisphere…
The AO Index fell all the way to -5.6, which was one of its lowest readings on record, dating back to 1950. As this occurred, near record-breaking cold broke out in the U.K., which had its fourth-coldest March since 1962. Germany saw its coldest March since 1883, and Moscow had its coldest March since the 1950s, according to NASA and news reports.
However, temperatures have been correspondingly above normal in the Arctic. Compare Greenland to Europe in this NASA map (blue for below-average temperature, red for above):
And here’s a crazy unseasonable crackup in the Beaufort Sea:
At least over the next month or two, we’re supposed to have nicer weather. This summer could be a doozy.