Weather or Not: What is the Jet Stream?

What is the Jet Stream?

(KSLA) - High above the surface you stand on is the jet stream that impacts our weather every day and you may not even know. What exactly is the Jet Stream?

The Jet Stream is a fast-flowing current of air located 5 to 7 miles above the Earth's surface. It is several thousand miles wide and long, but is very thin. The jet stream is created between two air masses of different densities and temperature. The pressure differences create a wind in between them, forming the jet stream.

There are two distinct currents in the northern hemisphere: polar jet and the subtropical jet.

The jet stream is important because it pushes weather patterns from west to east. For the most part weather doesn't stay in one place for too long, this is because it moves along the path of the jet stream.

Jet streams move to different positions throughout the year and follow temperatures and pressure differences. The jet stream forms a ridge near higher pressure and a trough near lower pressure. For more on high and low pressure, click here.

The seasons have a huge impact on where the jet stream is located. These graphics are approximate locations of the jet stream during the summer and winter. El Nino and La Nina influence the jet stream and can cause different patterns.

During the summer months, the subtropical jet influences our weather more. It moves northward from the Caribbean and Mexico. During the summer, there is less of a temperature gradient or difference in temperatures from the northern and southern portions of the United States. Because of this, the winds in the jet stream are much weaker.

During the winter months is when the polar jet will influence our weather more. The polar jet will move southward from Canada. This can cause arctic air to move into the United States and depending on how deep the trough is, bring that air right here to the ArkLaTex. Because of the strong temperature gradient, the winds of the jet stream are much stronger.

The jet stream is also important for aviation. If the plane you are flying on gets close to the jet stream and it is flowing quite fast, it can reduce travel time and how much fuel is used. The jet stream also has carried Saharan Dust from Africa and carried smoke from the California wildfires across the United States.

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