A: If the bumps are associated with rain, such as in a thunder storm, the answer is yes. Pilots use radar in those situations to avoid turbulence contained in thunderstorms. The rain, or moisture, is needed for the radar to display the storm or, as the pilot would say, “paint the weather” on his radar screen.
Turbulence not associated with moisture, often called “clear-air turbulence,” is not displayed on aircraft radar. In these situations, pilots use weather forecasts and/or reports from other pilots (called “pireps”) in aircraft flying ahead of them.
Although experts can forecast clear-air “bumps” with very sophisticated equipment, and pilots can report them, it is not always possible to detect and avoid them. That is why it is important to always return to your seat when the captain turns on the seatbelt sign, and to wear your seatbelt at all times while you are in your seat.
Captain Calvin Janacek is United’s Chicago chief pilot.
You can write to United’s chief pilots by addressing firstname.lastname@example.org