It seemed that airplanes arriving and departing from Will Rogers World Airport in Oklahoma City, Oklahoma, United States, on the morning of Aug. 3, 2012, would have few problems with wind conditions. The air was dry, and the surface weather map was devoid of any significant systems, typical of summer in the Southern Great Plains. Winds were light at the surface, running about 5 kt. And winds well aloft also were weak, less than 25 kt to 40,000 ft. So imagine the surprise when pilots ran into winds in excess of 40 kt just 1,600 ft above the ground. This was an example of what meteorologists call a “low-level jet stream” or a “low-level jet.”
Jet streams are fast-moving currents of air that have been likened to rivers in the sky. For many years, meteorologists only theorized about their existence. Driven by the inherent temperature contrasts on Earth and the effects of the planet’s rotation — the Coriolis effect — the air never is still. In the meteorologists’ view, fl…
