What is the Jet Stream?
The jet stream is a stream of wind that flows high above the earth, and moves from east to west over our state. Storms out over the ocean change how the jet stream passes over us and where it comes from. Sometimes the jet stream flows southward from Alaska and Canada. When it does, it brings colder weather to Idaho. At other times, storms off the coast of California and sometimes as far away as Hawaii send warm, moist air over our state and cause our weather to change. The next time you watch a weatherman on television, listen to how he explains why our weather will be what it is. Usually, he will talk about how the jet stream affects our weather. In this image supplied by AccuWeather, we can see the jet stream as a blue line.