Bottom line - shear rate is not a measure of turbulence. On LIDO, it's recently gone from a scale of 0-5 to 0-10. It is suggested that upwards of 4, there may be a risk of significant turbulence, and I would brief the cabin crew accordingly. It's better that they are warned about potential turbulence before the flight, even if it comes to nothing. That's the non-technical users' guide .... which shouldn't be in this forum, of course
