WASHINGTON (AP) – Anchorage, Alaska, was warmer Tuesday than Jacksonville, Florida. The weather in the U.S. is that upside down.

That’s because the Arctic’s deeply frigid weather escaped its regular atmospheric jail that traps the worst cold. It then meandered south to the central and eastern United States.

And this has been happening more often in recent times, scientists say.

___WHY IS IT SO COLD?

Super cold air is normally locked up in the Arctic in the polar vortex, which is a gigantic circular weather pattern around the North Pole. A strong polar vortex keeps that cold air hemmed in.

Source: Science Says: Why there’s a big chill in a warmer world – SFGate