Severe in-flight turbulence is on the rise, according to climate researchers, and more and more flights are likely to risk posing injuries to passengers when turbulence suddenly hits. While the worst turbulence tends to come without warning, much of it can be predicted, and the turbulence-tracking website Turbli.com gives free forecasts of a flight’s turbulence from take-off to landing. In addition to predictions of delays that headwinds might cause, the website uses data from US and UK weather services to create annual rankings for turbulence-prone airports and routes. South America has the w…