How do jet streams affect weather?
Jet streams are narrow bands of fast winds that generally flow west to east near the top of the troposphere.
Formation process and geographic mechanism
Temperature contrast between equator and poles creates an upper-level pressure gradient, while Earth's rotation turns the flow into a winding westerly current. The jet forms ridges and troughs rather than a straight line. These waves steer warm and cold air, fronts and developing low-pressure systems. Speed and position shift by season.
Spatial outcomes, measurement and management
A northward or southward shift alone cannot specify a city's weather; moisture, surface pressure and topography also matter. Aircraft may use tailwinds in one direction and face longer travel in the other. Climate-change effects on jet waviness remain active research, and no single extreme event is assigned to one cause automatically.