The Northern Hemisphere stratospheric polar vortex is a belt of fast-moving air circulating around the North Pole. Sometimes the stratospheric polar vortex can stretch southward over the United States. A stretched stratospheric polar vortex reflects upward waves back down, left, which affects the jet stream and surface weather, right. If the climate is warming, why are we still getting severe winter storms? One factor may be increasing disruptions to the stratospheric polar vortex , which appear to be linked to the rapid warming of the Arctic with climate change.