Spring officially arrived, as scheduled, this year on March 20, but residents of much of the United States and Canada would be hard-pressed to believe it.
Last month was the second coldest March of the 21st Century, and 13 degrees colder than last March.
It shows. Just take a look at the animation above, showing the area surrounding the western Great Lakes earlier this week and at this the same time last year. The difference is stark. Here in Maine, at the Farmers’ Almanac’s head office, the cold spring provide a sharp contrast to last year’s unusual 85 degree days during the opening days of the season.
So why has it been so cold?
During a normal spring, the jet stream carries warm air up from the Southern Hemisphere. This year, however, a large high pressure system — essentially a stationary mass of warm air – has stagnated over the Atlantic Ocean and Greenland, blocking the normal flow of weather systems.
Instead, that high pressure system has redirected the flow of air so that Arctic air from the Northwest blast down across the Canada and the Great Lakes, punishing the Midwest and Eastern U.S.
Fortunately for those who are longing for spring, the high-pressure has already begun to dissipate, and should loosen its grip soon, allowing spring to truly get underway.