The jet streams follow the contours of low and high pressure areas (troughs and ridges), which move like waves in the atmosphere across the earth. How does the polar jet stream impact winter weather in the Northern Hemisphere? A) The polar jet stream moves south brings large amounts of snow and ice. B) When the polar jet stream dips farther south and brings colder temperatures. C) The polar jet stream bumps into the stronger tropical jet stream causing lots of rain and snow. D) The polar jet stream moves horizontally across the United States, causing colder temperatures in northern states only.