While it’s been a frigid winter in the eastern U.S., the western region of the country has seen record warmth
원본 콘텐츠
The latest bout of brutally cold weather that has beset the eastern U.S. for weeks sent wind chills into the negative teens and 20s Fahrenheit (negative mid-20s to negative low 30s Celsius) in the U.S. Northeast over the weekend. Meanwhile, out West, winter has brought record-breaking warmth that is more suited for spring and even summer. “I’m sitting here in a T-shirt in early February, a mile high in Colorado,” says climate scientist Daniel Swain of the California Institute for Water Resources. This stark disparity is the product of a persistent atmospheric pattern. That pattern is about to break, however, and the weather fortunes of the two halves of the country are set to switch. To explain what’s happening, let’s review a favorite winter weather bugaboo: the polar vortex. The vortex is like a circular rushing river of wind that corrals the bitterest cold air up in the Arctic. When the vortex weakens, that tight circle becomes wavier, akin to how a slow-moving river tends to ...