MetEd COMET is a training program for forecasters world wide providing professionally produced training on a variety of topics. It requires some background in atmospheric science, but is nonetheless useful for pilots who want a deep dive into a weather topic.

Take a look at their web site:

https://www.meted.ucar.edu/

Search for "Forcasting Mountain Wave Turbulence for Aviation" Published 12/21/2016

You'll have to register online, but there are no other restrictions or pay walls involved.

I've just browsed the printable version of the training and have not carefully review it. You can view it online, or download a zipped file for instruction offline.

Walt Rogers WX