Originally Posted by
langleybaston
CAT is not necessarily a feature of jet streams, and has a variety of causes from the surface upwards.
The best practical answer might come from a hot air ballooner or a glider pilot near the stall in wind sheer conditions.
Unpleasant at an informed guess.
I am white knuckle self loading freight, having lectured on "Met. hazards to aviation" for three years. Too much information as they say.
Your informed guess is correct.
I have done a lot of glider-towing in lee-wave conditions at Cowley Alberta, which is Canada's premier wave-soaring location*. Last October, I had some of the most severe CAT I have ever experienced, such that I am debating wearing a parachute in future! We normally try to tow towards the lower, southern end of the Livingstone Range, which generates the wave, to try and avoid the rotor turbulence.
However, on two occasions, very experienced glider pilots had to release because they had lost control and on another flight, I watched my pen floating in front of me for several seconds!
A very experienced tow-pilot at my club used to say "The rotor is not rough, unless you get rolled inverted!"
* See
Cowley Canada's Diamond mine. There is a panorama on this page which shows the wooded lower ridge we aim for in order to minimize turbulence.