The Polar Jet Stream

Question

You've seen how atmospheric convection currents create low- and high-pressure systems at specific latitudes. At 0° and 60° N and S low-pressure systems are common. At 30° and 90° N and S high-pressure systems are
common.
But the band of Earth's surface between 30° and 60° N and S is not determined by convection currents. Rather, this band is controlled by the atmospheric currents both north and south.
Something interesting happens at 60°. Iwo circulation systems rub against each other. Cold air from the middle band (30°-60°) meets warm air from the adjacent band (60°-90°). And this boundary creates the polar jet stream. The polar jet stream is a narrow band of strong wind in the upper atmosphere.
How does the Polar Jet Stream impact air travel from west coast to east coast? One sentence.

Answer 1

The Polar Jet Stream can impact air travel from the west coast to the east coast by either speeding up or slowing down the flight time depending on the direction of travel.