Originally Posted by
Kooka
Because it is much, much more likely they went through the top of a buildup. You should look at all these “clear air” turbulence incidents with a great deal of cynicism. Night time, they’re always at night. In the tropics. Nowhere near a jet stream.
Daytime IMC is also when the 'fly into a buildup' occurs. About 15 yrs ago our Chief Pilot wrote "if it's night time, or daytime and you can't see the horizon, put the radar on. We've had 5 airplanes fly into the top of buildups in the last quarter."
Weather app showed no forecast turbulence for the area. It's not foolproof but it's pretty darn accurate. But it did show a small cluster of cells/buildups in the vicinity of where the event occurred.
The next question - what radar settings were being used? The calibrated settings won't show weather that you'd avoid if you could see it with your naked eye.