The Jet Stream

In the northern hemisphere, the jet stream acts as a boundary between northern latitude polar air, and mid latitude warm air. The jet stream can be described as a river of air moving West to East somewhere around 30,000 ft. It is in a constant state of fluctuation in speed, latitude, and altitude. During the summer months the jet stream tends to migrate north and reside mostly in Canada or along the border between Canada and the United States. A dip in the jet stream can be an indicator of an approaching cold front and the possibility for unstable weather or high winds. As the jet stream moves South into your area, you will notice the upper level air temperatures start to drop. This can decrease the overall stability of the region. If the jet stream is significantly North of your area, you don’t need to be concerned with it. If it is over your region or south of you, keep in mind that the weather conditions will likely be unstable and may change rapidly.