We are independent & ad-supported. We may earn a commission for purchases made through our links.

Advertiser Disclosure

Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.

How We Make Money

We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently from our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What is the Jet Stream?

By R. Kayne
Updated May 21, 2024
Our promise to you
AllThingsNature is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At AllThingsNature, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

The jet stream is a river of wind that blows horizontally through the upper layers of the troposphere, generally from west to east, at an altitude of 20,000 - 50,000 feet (6,100 - 9,144 meters), or about 7 miles (11 kilometers) up.

This stream of air develops where air masses of differing temperatures meet. For this reason, surface temperatures determine where the jet stream will form. The greater the difference in temperature, the faster the wind velocity inside the stream. Jet streams can flow up to 200 mph (322 km/h), are thousands of miles long, hundreds of miles wide, and a few miles thick.

Cold polar air flowing down from the north meets the warmer air mass over the United States causing the polar jet stream to form. Areas of high and low pressure act like a moving riverbed, buckling and snaking the path of the air as it flows to the east. At times, it may dip further south into the U.S., bringing cold weather with it. At other times it retreats into Canada, leaving milder weather in the U.S.

During the winter, a second jet stream forms in the lower latitudes. It separates the air mass over the U.S. from warmer air masses rising from south of the equator. This is called the subtropical jet stream.

Within the streams of air, currents travel at varying speeds but are greatest at the core. Jet streaks are areas inside the stream where the velocity is higher than the rest of the air. These streaks cause air to rise, which lowers the pressure at the surface. When surface low pressures form, the rising air can cause clouds, precipitation and storms. Therefore understanding and observing the jet stream is instrumental in accurate weather forecasting.

The jet stream can also contain windshear, a violent and sudden change in wind direction and speed. Windshear can occur outside the stream as well, even at the surface. When vertical winds blast downward, it can cause an airliner that is in the process of take off to suddenly lose altitude and potentially crash. For this reason, all commercial planes in the U.S. since 1996 have been equipped with windshear warning systems.

In the final days of World War II, the jet stream was discovered when fighter planes flying to Japan found they were not making headway against the strong easterly winds. They ultimately changed altitude to make the flight. Today, trips to the east coast by commercial airliner are shorter in duration than trips to the west coast, due to the stream of air pushing the planes east.

There are those who have "walked" in the jet stream. Mt. Everest, at over 29,000 feet (8,839 m), is so high that its summit actually sits in the river of air with prevailing winds at about 118+ mph (190 kph). Standing on the summit is a dangerous business and one has to pick the right moment carefully. Most prefer to summit in early May or fall when the air pushes northward over Tibet.

Frequently Asked Questions

What is the jet stream and how does it form?

The jet stream is a high-altitude band of strong winds, typically found 5 to 9 miles above the Earth's surface, that forms at the boundaries of air masses with different temperatures. The temperature contrast between these air masses causes the wind to increase in speed and concentrate into a jet-like current, which is further influenced by the Earth's rotation.

How does the jet stream affect weather patterns?

The jet stream plays a crucial role in shaping weather patterns by steering storm systems and influencing temperature distribution. It can bring rapid weather changes, such as sudden cold snaps or heatwaves, depending on its position and strength. For instance, a northward meander of the jet stream can pull warm air from the tropics, leading to warmer conditions in higher latitudes.

Are there different types of jet streams?

Yes, there are several types of jet streams, with the most prominent being the polar jet stream and the subtropical jet stream. The polar jet stream occurs at higher latitudes and is associated with the boundary between polar and temperate air masses. The subtropical jet stream is found at lower latitudes and is related to the boundary between tropical and temperate air masses.

How do jet streams influence aviation?

Jet streams significantly impact aviation, as flying with the jet stream can reduce flight times and fuel consumption due to the tailwind effect. Conversely, flying against it can lead to increased flight times and fuel usage. Pilots often plan routes to take advantage of these high-speed winds or to avoid turbulence associated with them.

Can the jet stream change over time?

Yes, the jet stream can change over time due to natural climate variability and human-induced climate change. Factors such as the El Niño Southern Oscillation can temporarily alter the jet stream's pattern. Additionally, research suggests that global warming may be influencing the jet stream, potentially leading to more persistent and extreme weather events.

How do scientists predict the movement of the jet stream?

Scientists predict the movement of the jet stream using sophisticated computer models that take into account a multitude of atmospheric variables. These models simulate the Earth's atmosphere and use current weather data to forecast the jet stream's path. Meteorologists then interpret this data to make predictions about future weather patterns and their potential impacts.

AllThingsNature is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Link to Sources

Discussion Comments

By anon322681 — On Feb 28, 2013

How does the jet stream affect the weather on a mountain top?

By anon21759 — On Nov 21, 2008

(Jetwet) Oscillations in the (polar) jet stream are referred to as Rossby waves.

By JetWet — On Nov 02, 2008

Is there an oscillatory pattern to the jet stream descending into the west coast of the US? If so does it have a name?

By raymondl — On Aug 28, 2007

Is JetStream the primary factor for planning/plotting cross-Pacific flight routes ? Note that East-bound flights (e.g. from Beijing to LAX) has different route than the West-bound ones (from SFO/LAX to Beijing).

AllThingsNature, in your inbox

Our latest articles, guides, and more, delivered daily.

AllThingsNature, in your inbox

Our latest articles, guides, and more, delivered daily.