From Toronto to Minneapolis, Chicago to Omaha many places in North America are seeing a surge in summer heat well into fall. But one of the drivers is a weather phenomenon occurring thousands of miles away, in the Pacific Ocean.  A marine heat wave, stretching from the coast of Japan to North America, is contributing to higher temperatures—and is expected to have a crucial impact on winter forecasts.  Here’s what to know.  What is a marine heat wave and does climate change impact it? Marine