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One of the most turbulent of these phenomena is known as sudden stratospheric warming. Westerly winds in the stratosphere periodically reverse, resulting in big temperatures swings, during which parts of the stratosphere can warm by as much as 90 degrees F (50 degrees C) in a couple of days.
This is typically accompanied by a rapid sinking of air that pushes onto the Atlantic jet stream at the top of the troposphere. The jet stream, which drives weather systems widely across the Northern Hemisphere, begins to snake. This disturbance can cause a variety of extreme weather, from persistent intense rains to summer droughts and “blocking highs” that can cause weeks of intense cold winter weather from eastern North America to Europe and parts of Asia.