Walter has always been spot on with his last point.
A 15 to 25 kt tailwind striking a cliff face will cause compression and updraft.
This will give an increase of speed and also considerable updraft causing a high ROC.
It will also generate vortices creating moderate to severe turbulence, plus local downdraughts within the general updraft.
This makes all analysis/ simulation and even flights trying to match the exact conditions all speculative.