Scientists thought turbulence, outside of clouds and thunderstorms, was caused by jet streams and changes in wind speed. These episodes of turbulence are known as wind shear. Recent research suggests thunderstorms have far-reaching effects by modifying airflow, which strenghthens the jet stream and increases wind shear at a significant distance from a designated storm cell. Researchers at the University of Melbourne report domestic flights along international routes between the U.S. and Australia vector around storm cells, but could still encounter wind shear and clear-air turbulence. The identification of near-cloud turbulence may change the FAA’s guidelines for thunderstorm detection. Around 15 passengers are injured each year by turbulence, with industry costs at $100 million per year. Fastcast: Wet again.