Weatherz School: Jet stream

Hearing “jet stream” may evoke an image of a jet plane. It turns out there is a connection between the two. Pilots get a front row seat to this important weather feature. As we dive into the jet stream, we need to hit the skies.

The jet stream is a current of strong winds high in the atmosphere. Reaching all around the globe, it’s a large-scale feature that can have big impacts on our local weather. The jet stream is driven by differences in temperature, and temperature changes with latitude.

The equator receives more heat from the sun than anywhere else. That’s why it gets colder as you move toward the poles. Jet streams form where the warm and cold areas come together.

On average, jet streams move at about 110 miles per hour. They can pick up past 250 miles per hour. That tends to happen in the winter when the temperature difference between the poles and the tropics are most extreme.

The winds in jet streams blow from west to east, but the flow often shifts to the north and south, creating what we call ridges and troughs. The jet stream helps steer weather systems. Some ride the jet.

If the jet is weak or if a weather system is far away from the jet stream, we get stretches of days with the same weather in the same areas. This can lead to droughts and floods, heat waves and cold snaps.

Jet streams can even effect air travel. Jets are typically 5 to 9 miles above the earth. Planes flying with the jet make great time, but going against it can delay your arrival.