The principle is simple. Warm, toasty air in the Arctic is melting the ice. Then the warm Arctic air plunges south and cools sixty or seventy degrees as it mixes with warm tropical air.
Using climate math, the average of 80 and 32 is -34. Most climate scientists probably never should have made it past third grade.
Last winter, missing Arctic ice made the US warm, but this winter it is making the US cold.
h/t to Marc Morano