Although it may seem counter-intuitive, the explosive brush fires raging in Southern California and the frigid weather gripping the eastern U.S. are connected. They are the consequences of an extreme jet pattern that makes the West hot and dry, and simultaneously the East cold.  New research suggests that climate change and shrinking sea ice may contribute to more frequent instances of starkly contrasting weather across the U.S.

The overarching weather pattern responsible for the contrasting extremes between the coasts is known as the North American Winter Dipole. Scientists use this term to describe abnormally warm conditions in the West and cold conditions in the East. Under such a pattern, the jet stream, the super highway for storms that divides cold and warm air, surges north in the western half of the nation, and crashes south in the eastern half.