Jet Stream

Jet Stream is a narrow band of strong winds (typically 60-250+ knots) found at altitudes between 25,000 and 45,000 ft, flowing from west to east in both hemispheres. Jet streams are caused by temperature gradients between air masses.

Aviation impact:

• Tailwind benefit: Eastbound flights route through the jet stream to save fuel and time
• Headwind penalty: Westbound flights route around or below the jet stream
• CAT: Clear Air Turbulence frequently occurs along jet stream boundaries

Daily jet stream analysis is fundamental to flight planning, especially for transatlantic and transpacific routes. The North Atlantic Tracks (NATs) are repositioned daily based on jet stream position.