How The Jet Stream Influences Weather

by Joshua

Driving, Forecasting Weather, weather maps, winter

jet-stream-photo-by-jurvetson.jpg You’ve probably heard about the jet stream, but maybe you aren’t exactly sure what a jet stream does.

Jet streams play a very important part in determining the type of weather we have.

They’re currents of wind which meander in the atmosphere 20,000 to 30,000 feet or more above the ground.

If you watch your local weather forecast, you’ll likely see the jet stream represented as a blue ribbon across the weather map.

Because jet streams can drive the weather, meteorologists attempt to forecast them and the types of weather they will likely bring.


Why The Jet Stream Is Important

A jet stream, being a strong current of wind, plays a vital weather role in these ways:



Because jet streams are currents of wind which circle the world, their impacts are felt not just regionally but also globally.

Jet streams blow from west to east with winds of 50 knots or greater. They are a general feature in Earth’s upper-level winds.


Different Kinds Of Jet Streams

There are generally 2 types of major jet streams:

Beyond that, the polar jet stream is found about 20,000 to 25,000 feet above the ground and is stronger than the subtropical jet stream. However, the subtropical jet stream is located over 30,000 feet in the atmosphere.

The region of the atmosphere where the main jet streams form is called the tropopause. This is the area between the troposphere and the stratosphere.


Why Do Jet Streams Form?

Earth’s rotation is extremely important in causing our weather. Friction and movement in the atmosphere caused by our planet’s rotation influence the wind patterns in the upper atmosphere.

The result of the atmosphere being affected by this rotation is a series of various winds which tend to flow between different types of air masses.

Relatively cold temperatures near the poles influence the polar jet streams (both hemispheres have a polar jet stream). Warmer regions close to the equator cause the sub-tropical jet streams, which are found north and south of the equator.


Jet Stream Fun Fact

Did you know?…


Bringing Cold Weather South For The Winter

The polar jet stream is a crucial player in determining how cold winter gets in the United States — especially in the southern states.

The polar jet stream often dives southward. When this happens, it can plow cold fronts to regions as far south as Florida.

In fact, when the polar jet stream plunges south over the United States during the winter time, you can almost guarantee some very cold weather will follow.


Low-Level Jet Streams

Jet stream currents generally are found high in the atmosphere, but similar currents of high-speed winds can also occur closer to the ground — sometimes less than 1,000 feet up.

Low-level jet streams can also affect weather patterns.